WO2024171832A1 - Wireless communication device - Google Patents

Abstract

Provided is a wireless communication device which is capable of communicating with a base station at a plurality of frequencies and is reduced in size.　The wireless communication device comprises: a signal processing unit; a housing in which the signal processing unit is contained; a first antenna which is provided outside the housing, is connected to the signal processing unit via a transmission cable, and communicates with a base station using radio waves of a first frequency; a second antenna which is provided in the housing or on the outer surface of the housing, is connected to the signal processing unit, and communicates with the base station using radio waves of a second frequency lower than the first frequency; and a third antenna which is connected to the signal processing unit and communicates with a terminal.

Description

Wireless communication device

This disclosure relates to a wireless communication device.

　Conventionally, there is a transceiver unit that is installed on the window glass of a building. The transceiver unit has an antenna unit that is installed on the outside surface of the window glass, and a power supply unit that is installed on the indoor surface of the window glass. The power supply unit supplies power to the antenna unit through the window glass. The antenna unit includes a first antenna plate and a second antenna plate. The first antenna plate receives radio waves from outdoors, and the second antenna plate radiates the signal received by the first antenna plate indoors (see, for example, Patent Document 1).

JP 2022-531502 A

However, if the number of antennas for communicating with external base stations increases, placing multiple antennas in one housing will result in the device becoming larger.

The objective is to provide a compact wireless communication device that can communicate with a base station on multiple frequencies.

A wireless communication device according to an embodiment of the present disclosure includes a signal processing unit, a housing that houses the signal processing unit, a first antenna that is provided outside the housing and connected to the signal processing unit via a transmission cable and communicates with a base station using radio waves at a first frequency, a second antenna that is provided inside the housing or on the outer surface of the housing and connected to the signal processing unit and communicates with the base station using radio waves at a second frequency that is lower than the first frequency, and a third antenna that is connected to the signal processing unit and communicates with a terminal.

It is possible to provide a compact wireless communication device that can communicate with a base station on multiple frequencies.

1 is a diagram showing an example of a building in which a wireless communication device according to an embodiment is installed, as viewed from the side; FIG. 1 illustrates an example of a configuration of a wireless communication device according to an embodiment. FIG. 2 illustrates an example of a configuration of a first antenna of the wireless communication device according to the embodiment. 2 is a diagram illustrating an example of a circuit configuration of a signal processing unit of the wireless communication device according to the embodiment. 11 is a diagram illustrating an example of a configuration of a first antenna of a wireless communication device according to a first modified example of an embodiment. FIG. FIG. 13 is a diagram illustrating an example of a configuration of a wireless communication device according to a second modified example of the embodiment.

Below, an embodiment in which the wireless communication device of the present disclosure is applied will be described. In the following, the same elements will be given the same reference numerals, and duplicated explanations may be omitted.

The following defines and explains the XYZ coordinate system. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are mutually perpendicular. In addition, the length, width, thickness, etc. of each part may be exaggerated below to make the configuration easier to understand. Furthermore, terms such as parallel, right angle, orthogonal, horizontal, vertical, up and down, etc., are permitted to be misaligned to the extent that they do not impair the effect of the embodiment.

In the following explanation, "radio waves" refers to a type of electromagnetic wave, and generally, electromagnetic waves below 3 THz are called radio waves. Below, electromagnetic waves emitted from outdoor base stations or relay stations will be called "radio waves", and electromagnetic waves in general will be called "electromagnetic waves". In addition, below, when we refer to "millimeter waves" or "millimeter wave band", we mean not only the frequency band of 30 GHz to 300 GHz, but also the quasi-millimeter wave band of 24 GHz to 30 GHz.

<Embodiment>
The wireless communication device of the embodiment can function as a repeater that receives radio waves coming from a base station or a relay station, performs processing such as amplification without converting the frequency, and then radiates the radio waves. The wireless communication device of the embodiment can also function as a repeater that receives radio waves coming from a base station, performs processing such as frequency conversion and amplification, and then radiates the radio waves.

The wireless communication device of the embodiment is capable of transmitting and receiving radio waves of a first frequency and radio waves of a second frequency between a base station or a relay station. The second frequency is lower than the first frequency.

The radio waves of the first frequency are radio waves in a frequency band equal to or greater than a specified frequency. The specified frequency is approximately 1 GHz to 3 GHz. As an example, the radio waves of the first frequency are radio waves in the millimeter wave band of the fifth generation mobile communication system (5G) or in a frequency band equal to or greater than a specified frequency of Sub-6, LTE (Long Term Evolution), LTE-A (LTE-Advanced), or UMB (Ultra Mobile Broadband).

The second frequency radio wave is a radio wave with a frequency lower than a predetermined frequency. The predetermined frequency is about 1 GHz to 3 GHz. As an example, the second frequency radio wave is a radio wave with a frequency lower than the predetermined frequency of Sub-6, LTE, LTE-A, or UMB, such as the fifth generation mobile communication system (5G).

In addition, when the wireless communication device of the embodiment radiates radio waves received from a base station or relay station as a repeater, the radio waves of the first frequency and the second frequency described above may be amplified or otherwise processed before being radiated without frequency conversion.

In addition, when the wireless communication device of the embodiment radiates radio waves received from a base station or relay station as a repeater, it may perform processing such as frequency conversion and amplification on the radio waves of the first frequency or the second frequency described above, and radiate the radio waves as radio waves of IEEE802.11 (Wi-Fi (registered trademark)), IEEE802.16 (WiMAX (registered trademark)), IEEE802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), or LPWA (Low Power Wide Area), etc. Of these, Wi-Fi and WiMAX can be used as wireless LANs (Local Area Networks).

<Overview of wireless communication device 100>
Fig. 1 is a diagram showing an example of a building 1 in which a wireless communication device 100 according to an embodiment is installed, as seen from the side. In addition to the building 1 and the wireless communication device 100, Fig. 1 also shows base stations BS1 and BS2, and a smartphone 50. The base stations BS1 and BS2 are examples of external devices. Fig. 1 shows the base stations BS1 and BS2, but the external device of the wireless communication device 100 may be a relay station. Even if the external device of the wireless communication device 100 is a relay station, the wireless communication device 100 will communicate with the base station via the relay station.

Below, the operation and configuration of the wireless communication device 100 may be described using the operation of the wireless communication device 100 receiving radio waves. Since the operation of the wireless communication device 100 transmitting radio waves is the opposite operation to the operation of receiving radio waves, the description of the operation of the wireless communication device 100 transmitting radio waves may be omitted.

The building 1 may be a detached house, a building, an apartment, or a commercial facility such as a shopping mall or a department store, an airport, a factory, a power facility, a government building, a station (station building), or a bus stop building. The window 10 is used in these buildings 1. The window 10 includes a window glass 11 and a window frame (the window frame on the building 1 side). The wireless communication device 100 is installed inside the building 1 as an example, and has a function as a repeater that relays radio waves arriving from the outside to the inside and relays radio waves from the inside to the outside. Note that, as an example, a form in which the wireless communication device 100 is installed inside the building 1 will be described here. However, the wireless communication device 100 may be installed outdoors as long as there are areas where radio waves of a first frequency described later cannot reach and areas where they can reach.

In FIG. 1, as an example, the XYZ coordinate system is defined based on the indoor principal surface of the window glass 11. The indoor principal surface of the window glass 11 is the principal surface parallel to the XY plane on the +Z direction side of the window glass 11. The building 1 has a wall 1W parallel to the XY plane on the -Z direction side, and the window 10 is provided in the wall 1W.

As an example, base station BS1 transmits and receives radio waves of a first frequency, and base station BS2 transmits and receives radio waves of a second frequency. As described above, the first frequency is a frequency equal to or higher than a predetermined frequency, and the second frequency is a frequency lower than the predetermined frequency. The predetermined frequency is approximately 1 GHz to 3 GHz. Note that, although the explanation is given here separately for base station BS1 and base station BS2, a single base station may transmit and receive radio waves of the first frequency and the second frequency.

The first frequency is the frequency of radio waves that do not penetrate the wall 1W of the building 1, and the second frequency is the frequency of radio waves that penetrate the wall 1W of the building 1. The predetermined frequency that is the boundary between the first and second frequencies is approximately 1 GHz to 3 GHz, depending on the material and structure of the wall 1W. Note that radio waves not penetrating the wall 1W of the building 1 does not only mean that radio waves do not penetrate the wall 1W at all, but also means that the radio waves that penetrate the wall 1W are weak and do not provide sufficient radio wave strength for practical use to communicate with terminals such as smartphone 50 and PC (Personal Computer) inside (indoors) the wall 1W of the building 1.

The first frequency radio waves emitted from base station BS1 do not penetrate the wall 1W of building 1, and therefore penetrate only the pane 11 of window 10 to enter the building. Because the first frequency radio waves have a high degree of directional propagating ability, they only reach the line of sight (LOS) area of window 10, which makes it easy for blind zones to form inside the building. The pane 11 of window 10 is the entry point for the first frequency radio waves into building 1.

In addition, the second frequency radio waves emitted from base station BS2 penetrate the window glass 11 of the window 10 of building 1 and the wall 1W and enter the building, reaching not only the line of sight (LOS) area of the window 10 but the entire interior of building 1. For this reason, it is difficult for dead zones to occur indoors for the second frequency radio waves.

The wireless communication device 100 includes a first antenna 110 provided on the indoor main surface of the window glass 11 of the window 10 in order to transmit and receive radio waves of a first frequency to and from the outdoor base station BS1. The first antenna 110 is connected to the device body 101 via a transmission cable 115. The wireless communication device 100 includes a plurality of first antennas 110 as an example. In FIG. 1, a plurality of first antennas 110 are shown together, but each of the first antennas 110 is connected to one transmission cable 115. Since FIG. 1 shows four transmission cables 115 as an example, FIG. 1 shows a configuration in which four first antennas 110 are provided as an example. Details of the configuration of the first antennas 110 will be described later with reference to FIG. 3. Note that the wireless communication device 100 may include one first antenna 110.

Also, a matching layer 117 is provided between each first antenna 110 and the indoor main surface of the window glass 11. A liquid crystal phase shifter 118 is provided on the +Z direction side of each first antenna 110. That is, the first antenna 110 is provided between the matching layer 117 and the liquid crystal phase shifter 118. As an example, the first antenna 110 is adhered to the window glass 11 by a fixing member such as a holder (not shown). The matching layer 117 is held between the window glass 11 and the first antenna 110 by a holder (not shown). As an example, the liquid crystal phase shifter 118 is held on the +Z direction side of the first antenna 110 by a holder (not shown). Also, the liquid crystal phase shifter 118 may be held by directly adhering to the +Z direction side of the first antenna 110 with an adhesive layer or the like.

The liquid crystal phase shifter 118 is used when the wireless communication device 100 performs beamforming using the multiple first antennas 110 as a phased array antenna, but a phase shifter other than the liquid crystal phase shifter may be used instead of the liquid crystal phase shifter 118. However, since the liquid crystal phase shifter 118 consumes little power and generates little heat, it is preferable to install it on the window glass 11 in that it can suppress thermal cracking. Furthermore, if the wireless communication device 100 does not perform beamforming using the first antenna 110, the wireless communication device 100 does not need to include the liquid crystal phase shifter 118. Furthermore, if there is no particular problem in not including the matching layer 117, the wireless communication device 100 does not need to include the matching layer 117. The matching layer 117 and the liquid crystal phase shifter 118 will be described later.

The wireless communication device 100 also includes a second antenna (not shown in FIG. 1) installed inside the device body 101, which is installed indoors, to transmit and receive radio waves of a second frequency to and from the outdoor base station BS2.

Then, as an example, the wireless communication device 100 performs amplification processing, or amplification processing and frequency conversion processing, on the radio waves of the first frequency received by the first antenna 110 and the radio waves of the second frequency received by the second antenna 120, and outputs them indoors from a third antenna (not shown) or the like provided on the device main body 101.

By outputting radio waves from the wireless communication device 100 indoors, the signals can be easily received by devices indoors such as smartphones 50 and PCs.

<Specific configuration of wireless communication device 100>
A specific configuration of the wireless communication device 100 will be described using Fig. 2 and Fig. 3 in addition to Fig. 1. Fig. 2 is a diagram showing an example of the configuration of the wireless communication device 100. Fig. 2 simplifies the configuration and shows one first antenna 110 and one transmission cable 115. Fig. 3 is a diagram showing an example of the configuration of the first antenna 110. Fig. 3 shows four first antennas 110 as an example.

The wireless communication device 100 includes a first antenna 110, a transmission cable 115, a matching layer 117, a liquid crystal phase shifter 118, a second antenna 120, third antennas 130A and 130B, connectors 135A-135C, a housing 140, and a signal processing unit 150. The connectors 135A-135C are an example of an input/output terminal. As described above, as an example, a form in which the wireless communication device 100 includes four first antennas 110 and four transmission cables 115 will be described here, but the wireless communication device 100 may include at least one first antenna 110 and one transmission cable 115.

The second antenna 120, the third antennas 130A and 130B, the connectors 135A to 135C, and the signal processing unit 150 are housed inside the housing 140. Of these, the connector 135C is provided inside the housing 140 with a portion of it exposed to the outer surface of the housing 140. The connector 135C is a connector into which a LAN cable located outside the housing 140 can be inserted and removed, and therefore a portion of it is exposed to the outer surface of the housing 140. Note that the wireless communication device 100 may be configured to include terminals to which the two third antennas 130A are connected, as an example of input/output terminals, instead of the connectors 135A and 135B. The terminals to which the two third antennas 130A are connected may be provided separately from the signal processing unit 150, for example, or may be provided in the signal processing unit 150. The terminals provided on the signal processing unit 150 may be terminals on the substrate of the signal processing unit 150, or terminals on an MCU (Micro Controller Unit) of a wireless module of the signal processing unit 150, which will be described later, etc.

The second antenna 120, the third antennas 130A and 130B, the connectors 135A to 135C, the housing 140, and the signal processing unit 150 constitute the device body 101. The device body 101 is not transparent to visible light and does not transmit visible light.

<Example of operation of wireless communication device 100>
Here, the following describes an example of the wireless communication device 100 performing the following operation. The wireless communication device 100 amplifies the radio waves of the first frequency received by the first antenna 110 in the signal processing unit 150 and radiates the radio waves indoors from the third antenna 130A. In addition, as an example, the wireless communication device 100 converts the radio waves of the second frequency received by the second antenna 120 into radio waves of a wireless LAN in the signal processing unit 150, amplifies the radio waves, and radiates the radio waves indoors from the third antenna 130B. Instead of a wireless LAN, UWB, Bluetooth (registered trademark), LPWA, or the like may be used. In addition, as an example, the wireless communication device 100 converts the radio waves of the second frequency received by the second antenna 120 into a signal for a wired LAN in the signal processing unit 150, amplifies the signal, and transmits the signal to a terminal (not shown) such as a PC located indoors via a LAN cable (not shown) connected to the connector 135C.

In this case, the wireless communication device 100 may be configured, for example, to perform either one of the following operations regarding the second frequency radio waves received by the second antenna 120: converting the radio waves into wireless LAN radio waves, amplifying the radio waves, and radiating the radio waves indoors from the third antenna 130B; or converting the radio waves into a signal for a wired LAN, amplifying the radio waves, and outputting the signal from the connector 135C. In this case, if the operation of outputting a signal for a wired LAN from the connector 135C is not performed, the wireless communication device 100 does not need to include the connector 135C for a wired LAN.

<Modification of the operation of the wireless communication device 100 (part 1)>
Also, the wireless communication device 100 may be configured to perform the following operation, for example, instead of the configuration for performing the above-mentioned operation. For example, the wireless communication device 100 may convert the radio wave of the first frequency received by the first antenna 110 into a radio wave of a wireless LAN in the signal processing unit 150, amplify the radio wave, and radiate the radio wave indoors from the third antenna 130A. In this case, for example, the wireless communication device 100 may convert the radio wave of the second frequency received by the second antenna 120 into a radio wave of a wireless LAN in the signal processing unit 150, amplify the radio wave, and radiate the radio wave indoors from the third antenna 130B. That is, both the radio wave of the first frequency received by the first antenna 110 and the radio wave of the second frequency received by the second antenna 120 may be converted into a radio wave of a wireless LAN, amplified, and radiated indoors from the third antennas 130A and 130B. Also, as an example, the wireless communication device 100 may convert radio waves of a first frequency received by the first antenna 110 into a signal for a wired LAN in the signal processing unit 150, amplify the signal, and transmit the signal to a terminal (not shown) such as a PC located indoors via a LAN cable (not shown) connected to the connector 135C. Also, as an example, the wireless communication device 100 may amplify radio waves of a second frequency received by the second antenna 120 in the signal processing unit 150, and radiate the signal indoors from the third antenna 130B.

In this case, the wireless communication device 100 may be configured, for example, to perform either one of the following operations: converting radio waves of the first frequency received by the first antenna 110 into wireless LAN radio waves, amplifying the radio waves, and radiating the radio waves indoors from the third antenna 130A; or converting the radio waves into a signal for a wired LAN, amplifying the radio waves, and outputting the signal from the connector 135C. In this case, if the operation of outputting a signal for a wired LAN from the connector 135C is not performed, the wireless communication device 100 does not need to include the connector 135C for a wired LAN.

<Modification of the operation of the wireless communication device 100 (part 2)>
Also, instead of being configured to perform the above-mentioned operations, the wireless communication device 100 may be configured to perform the following operations, for example. The wireless communication device 100 may be configured to amplify radio waves of the first and second frequencies received by the first and second antennas 110 and 120 in the signal processing unit 150 and radiate the amplified radio waves indoors from the third antennas 130A and 130B. In this case, the wireless communication device 100 does not need to include the connector 135C for a wired LAN.

<First Antenna 110>
The first antenna 110 is provided outside the housing 140 of the device main body 101, is connected to the signal processing unit 150 via a transmission cable 115, and is an antenna that communicates with the base station BS1 by radio waves of the first frequency. The first antenna 110 has a luminous transmittance of 50% or more. The details will be described later.

The device body 101 does not transmit visible light and would obstruct visibility if placed on the window 10, so it is placed on a flat surface such as a wall 1W near the window 10 on the indoor side, a bay window frame, or a floor. In this case, the device body 101 may simply be placed on a flat surface such as a floor.

The first frequency radio waves emitted from base station BS1 penetrate only through the window glass 11 of window 10 and enter the interior of the building, so in order for the first antenna 110 to receive the first frequency radio waves, it is preferable to place the first antenna 110 within the line of sight (LOS) area of the window 10. For this reason, the first antenna 110 is provided outside the housing 140. As the first antenna 110 is not provided inside the housing 140, the device main body 101 and the housing 140 can be made smaller.

More specifically, the first antenna 110 is provided on the indoor main surface of the window glass 11 of the window 10 as shown in FIG. 1. The first antenna 110 is connected to a connector 145 of the housing 140 of the device main body 101 via a transmission cable 115 as shown in FIG. 2. The transmission cable 115 is formed of a coaxial cable as an example. Although one connector 145 is shown in FIG. 2, as an example, the wireless communication device 100 includes four first antennas 110 and four transmission cables 115, four connectors 145 are provided on the housing 140.

Each first antenna 110 has a substrate 110A, an antenna element 111, a feed line 112, and branch lines 113 and 114. As an example, the substrates 110A of the four first antennas 110 are integrated.

The antenna element 111, the feed line 112, and the branch lines 113 and 114 are provided on the surface on the -Z direction side of the substrate 110A. The first antenna 110 has a ground layer provided on the entire surface on the +Z direction side of the substrate 110A, but this is not shown in FIG. 3. The ground layer is connected to a ground potential point (not shown).

FIG. 3 shows four antenna elements 111 of four first antennas 110. The configuration of the four antenna elements 111 is, for example, the same as each other. The pitch between adjacent antenna elements 111 is, for example, approximately λ/2, where λ is the wavelength at the communication frequency of the first antenna 110. The pitch between adjacent antenna elements 111 is the distance in the X direction between the centers of adjacent antenna elements 111.

As an example, the wireless communication device 100 is capable of, for example, MIMO (Multiple-Input and Multiple-Output) communication using four antenna elements 111 (first antenna 110). Also, as an example, the wireless communication device 100 may perform beamforming using the four antenna elements 111 (first antenna 110) as a phased array antenna. Also, as an example, the wireless communication device 100 may be configured not to perform MIMO communication or beamforming using the four antenna elements 111 (first antenna 110).

A feed line 112 and branch lines 113 and 114 are provided for each antenna element 111. Branch line 113 is an example of a first branch line, and branch line 114 is an example of a second branch line.

<Substrate 110A>
The substrate 110A is formed of any material that is transparent to radio waves radiated from the base stations BS1 and BS2 and that can support the antenna element 111, the feed line 112, and the branch lines 113 and 114. "Transparent to the radiated radio waves" means, for example, that the transmission loss is 10 dB or less. "The substrate 110A is transparent to the radiated radio waves" means that the transmission loss of the substrate 110A is 10 dB or less, preferably 6 dB or less, more preferably 3 dB or less, and even more preferably 1 dB or less.

The substrate 110A may also be transparent to visible light. "Transparent" to visible light means that the visual transmittance is at least 40%, preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more.

As an example, a resin substrate (resin film) may be used as the substrate 110A. Examples of resin materials that satisfy the above conditions include acrylic resins such as polymethyl methacrylate, cycloolefin resins, polycarbonate resins, and polyethylene terephthalate (PET). Also, a glass plate may be used as the substrate 110A. Examples of glass plates that satisfy the above conditions include soda-lime glass, alkali-free glass, Pyrex (registered trademark) glass, and quartz glass. Note that, as an example, a form in which the substrate 110A is a resin substrate will be described here.

<Overall configuration of antenna element 111, feed line 112, and branch lines 113 and 114>
The antenna element 111, the power feed line 112, and the branch lines 113 and 114 can be formed of, for example, a thin metal film of copper, nickel, gold, etc. When the substrate 110A is transparent to visible light, it is preferable from the viewpoint of visibility that the antenna element 111, the power feed line 112, and the branch lines 113 and 114 are formed of, for example, a mesh-shaped thin metal film of copper, nickel, gold, etc.

In addition, the antenna element 111, the power supply line 112, and the branch lines 113 and 114 may be formed of a transparent conductive film such as zinc oxide (ZnO), tin oxide (SnO ₂ ), tin-doped indium oxide (ITO), indium oxide-tin oxide (IZO), or the like, a metal nitride such as titanium nitride (TiN) or chromium nitride (CrN), or a Low-e film for Low-e glass.

As described above, the first antenna 110 only needs to have a visual transmittance of 50% or more if the substrate 110A is transparent to visible light and the antenna element 111, the feed line 112, and the branch lines 113 and 114 are made of transparent conductors such as mesh-like thin metal films.

<Antenna element 111>
The antenna element 111 has a rectangular shape in the XY plane (planar view of the first antenna 110) and constitutes a patch antenna together with a ground layer on the surface on the +Z direction side of the substrate 110A. The antenna element 111 has a feeding point 111A at the center of its width in the X direction at the end on the -Y direction side.

<Power supply line 112>
The feed line 112 is connected to the feed point 111A and extends from the feed point 111A in the −Y direction. The feed line 112 overlaps with the ground layer on the opposite side of the substrate 110A, and thus constitutes a microstrip line. The end of the feed line 112 on the −Y direction side is connected to the signal line of the transmission cable 115, and is connected to the signal processing unit 150 via the connector 145. When the transmission cable 115 is constituted by a coaxial cable, the signal line of the transmission cable 115 is the core wire of the coaxial cable. In this case, the shield wire of the transmission cable 115 is connected to the ground layer provided on the surface of the substrate 110A on the +Z direction side. In addition, instead of a coaxial cable, a waveguide, or a transmission line such as a microstrip line or a coplanar waveguide formed on a flexible substrate or the like may be used as the transmission cable 115.

<Branch line 113>
The branch line 113 branches off from the middle of the feed line 112 and extends in the −X direction, for example. The length of the branch line 113 is λe/2, where λe is the electrical length of the wavelength at the communication frequency of the first antenna 110. The length of the branch line 113 is the length in the extension direction between the end of the branch line 113 on the +X direction side where it is connected to the feed line 112, and the end (open end) on the −X direction side.

Branch line 114 is connected to midpoint 113A of the length of branch line 113 in the extension direction. The length of the section of branch line 113 on the +X side of midpoint 113A is λe/4, and the length of the section of branch line 113 on the -X side of midpoint 113A is λe/4. Since the distance to midpoint 113A and the distance to the end of branch line 113 on the -X side and the end on the +X side are both λe/4, midpoint 113A is a node of the AC voltage when antenna element 111 transmits and receives radio waves. In other words, the voltage at midpoint 113A is always 0V.

<Branch line 114>
The branch line 114 branches off from a midpoint 113A of the length of the branch line 113 in the extension direction, and extends, for example, in the −Y direction. This is because the branch line 114 is less likely to affect the radiation characteristics of the antenna element 111 if it extends in the −Y direction rather than the +Y direction.

The branch line 114 branches off from midpoint 113A of the length of the branch line 113 in the extension direction, and the voltage at midpoint 113A is always 0V. Therefore, connecting the branch line 114 to midpoint 113A of the branch line 113 is equivalent to a state in which nothing is connected to midpoint 113A of the branch line 113. In other words, the impedance of the branch line 114 theoretically does not affect the radiation characteristics of the antenna element 111. Such branch lines 113 and 114 form a choke structure.

Furthermore, the four branch lines 114 of the four first antennas 110 have different resistance values from each other. This is to make the four first antennas 110 identifiable. The branch lines 113 and 114 are an example of a choke structure and an example of an identification portion.

The resistance value of each branch line 114 is an example of a predetermined DC resistance value. As an example, the resistance values of the four branch lines 114 may be set to four different resistance values within a range of 0 Ω to 500 Ω.

A pad 114A is provided at the end of the branch line 114 on the -Y direction side, and as an example, a through-hole via that penetrates the substrate 110A in the thickness direction (Z direction) is provided in the pad 114A. The end of the through-hole via on the +Z direction side is connected to a ground layer provided on the surface of the substrate 110A on the +Z direction side.

When the four branch lines 114 are made of a mesh-like thin metal film, for example, they may have different resistance values due to differences in mesh density, etc. Furthermore, when the four branch lines 114 are made of a thin metal film, for example, they may have different thicknesses, lengths, materials, etc., so that they have different resistance values. Furthermore, when the four branch lines 114 are made of a thin metal film, for example, they may have different resistance values due to differences in thickness, length, material, etc. Furthermore, when the four branch lines 114 are made of a thin metal film, for example, they may have different resistance values due to differences in resistance values of the resistors inserted in series in each branch line 114. Here, a form having a mesh structure made of thin metal wires will be described.

Since the resistance values of the four branch lines 114 are different from each other, for example, when the wireless communication device 100 performs MIMO communication or beamforming with the four antenna elements 111 (first antenna 110), the signal processing unit 150 can identify the four antenna elements 111 (first antenna 110). This is because the signal processing unit 150 is connected to the antenna elements 111 and the ground layer on the surface on the +Z direction side of the substrate 110A via the transmission cable 115. Note that, as an example, when the wireless communication device 100 does not perform MIMO communication or beamforming with the four antenna elements 111 (first antenna 110), the resistance values of the four branch lines 114 may be equal to each other.

In addition, in both cases where the resistance values of the four branch lines 114 are different from one another and where the resistance values of the four branch lines 114 are equal to one another, the signal processing unit 150 can identify the attachment/detachment state of the four first antennas 110 to the four connectors 145. The branch lines 114 function as an identification unit.

Since the resistance value differs between when the first antenna 110 is connected to the signal processing unit 150 and when it is not connected, the signal processing unit 150 can identify the attached/detached state of the first antenna 110. Note that the identification unit is not limited to one that uses the resistance value, and may be, for example, an identification unit that can output identification information such as an ID (identifier).

<Transmission cable 115>
For example, the transmission cable 115 is detachable from the connector 145. That is, the transmission cable 115 is detachable from the housing 140. For example, the transmission cable 115 may be a coaxial cable.

<Matching layer 117>
As described above, the matching layer 117 (see FIG. 1 ) is provided between each first antenna 110 and the indoor main surface of the window glass 11. As the wireless communication device 100 includes, as an example, four first antennas 110, the wireless communication device 100 includes four matching layers 117, but these are shown as an integrated unit in FIG. 1 .

When radio waves of the first frequency pass through the window glass 11, the radio waves are attenuated. In order to suppress the attenuation (loss) of the radio waves, it is preferable to provide a matching layer 117. By using the matching layer 117, when the first antenna 110 transmits and receives radio waves, the electrical length of the radio waves passing through the window glass 11 can be adjusted to match the impedance, thereby reducing loss.

<Liquid crystal phase shifter 118>
The liquid crystal phase shifter 118 is provided on the +Z direction side of each first antenna 110. The liquid crystal phase shifter 118 and the signal processing unit 150 are connected via a signal line or the like (not shown). The dielectric constant of the liquid crystal layer of the phase shifter 118 is controlled by the signal processing unit 150 via a signal line or the like (not shown). Since the electrical length of the wavelength of the radio waves transmitted and received by the four first antennas 110 is changed, the phase of the radio waves transmitted and received by the four first antennas 110 can be changed. Beamforming is possible by using the antenna 110 as a phased array antenna.

As mentioned above, the liquid crystal phase shifter 118 is used when the wireless communication device 100 performs beamforming with the first antenna 110. If the wireless communication device 100 does not perform beamforming with the first antenna 110, the wireless communication device 100 does not need to include the liquid crystal phase shifter 118.

<Second Antenna 120>
The second antenna 120 is provided inside the housing 140 or on the outer surface of the housing 140, is connected to the signal processing unit 150, and communicates with the base station BS2 using radio waves of a second frequency lower than the first frequency.

The second frequency radio waves penetrate the walls 1W of the building 1, and therefore reach the entire interior of the building 1, unlike the first frequency radio waves which only reach the line of sight (LOS) area of the window 10. Therefore, the second frequency radio waves reach the housing 140 which is placed on the floor or wall 1W inside the building 1. For this reason, as an example, the second antenna 120 is provided inside the housing 140 or on the outer surface of the housing 140.

"Inside the housing 140" refers to the inside of the space surrounded by the outer wall of the housing 140, and "providing the second antenna 120 inside the housing 140" means that the second antenna 120 is located inside the housing 140. In this case, even if a part of the second antenna 120 is exposed to the outer surface of the housing 140, the second antenna 120 is considered to be located inside the housing 140. In addition, "the outer surface of the housing 140" refers to the surface of the outer wall of the housing 140, and "providing the second antenna 120 on the outer surface of the housing 140" means that at least a part of the second antenna 120 may be located outside the outer surface of the housing 140.

Here, as an example, the second antenna 120 is provided directly behind the outer wall of the housing 140. The directly behind the outer wall of the housing 140 is inside the housing 140 (inside the housing 140).

The window 10 is provided with a first antenna 110, and if more antennas are provided on the window 10, there is a risk that the visibility through the window 10 may be impaired. From this perspective, by not providing a second antenna 120 on the window 10, good visibility through the window 10 can be ensured.

The second antenna 120 is preferably provided directly behind the outer wall on the upper side of the housing 140 so as to be able to receive radio waves of the second frequency more efficiently. The second antenna 120 may be of any type as long as it is an antenna capable of receiving radio waves of the second frequency, but an inverted F antenna is preferable because it can provide a wide bandwidth. The wireless communication device 100 may be configured to include multiple second antennas 120. In this case, the wireless communication device 100 may be configured to perform MIMO communication using multiple second antennas 120, as an example.

< Third Antennas 130A and 130B>
As an example, the third antennas 130A and 130B are connected to the signal processing unit 150 via connectors 135A and 135B, respectively. The third antennas 130A and 130B may be antennas of an appropriate type according to the frequency of radio waves to be transmitted and received, etc.

As an example, the third antenna 130A radiates radio waves of the first frequency that have been received by the first antenna 110 and processed by the signal processing unit 150, such as amplified, into the interior of the building 1. In this case, the third antenna 130A may be any antenna capable of transmitting and receiving radio waves of the first frequency, and may be, for example, a patch antenna or a monopole antenna.

The third antenna 130B, for example, radiates indoors the wireless LAN radio waves that are received by the second antenna 120 and have their frequency converted and amplified by the signal processing unit 150. In this case, the third antenna 130B may, for example, be an antenna for the wireless LAN.

In this way, as an example, the third antenna 130A radiates radio waves of the first frequency indoors in the building 1, and the third antenna 130B radiates radio waves of the wireless LAN indoors, so that, as an example, the smartphone 50 can receive both radio waves of the first frequency and radio waves of the wireless LAN indoors in the building 1.

<Connectors 135A to 135C>
The connectors 135A to 135C are provided inside the housing 140 or on the outer surface of the housing 140, connected to the signal processing unit 150, and are connectors for inputting and outputting communication data transmitted and received by the second antenna 120. As for the connectors 135A and 135B, as described above, terminals to which the two third antennas 130A are connected may be used instead of the connectors 135A and 135B.

"Inside the housing 140" refers to the inside of the space surrounded by the outer wall of the housing 140, and "providing the connector 135A inside the housing 140" means that the connector 135A is located inside the housing 140. In this case, even if a portion of the connector 135A is exposed on the outer surface of the housing 140, the connector 135A is treated as being located inside the housing 140. In addition, the outer surface of the housing 140 refers to the surface of the outer wall of the housing 140, and "providing the connector 135A on the outer surface of the housing 140" means that at least a portion of the connector 135A may be located outside the outer surface of the housing 140.

Connectors 135A and 135B are connectors to which third antennas 130A and 130B are respectively connected. Connector 135C is a connector to which a LAN cable can be connected.

As an example, connectors 135A and 135B are provided inside housing 140. This is because third antennas 130A and 130B are connected to connectors 135A and 135B, respectively, in advance. As an example, connector 135C is provided on the outer surface of housing 140. As an example, this is to allow a LAN cable connector to be detached (inserted and removed) from connector 135C as necessary. Note that multiple connectors 135C for LAN cables may be provided.

As an example, if a LAN cable is used to connect the connector 135C and a PC, the communication data received by the second antenna 120 can be acquired by the PC, and the data in the PC can be radiated from the second antenna 120 via the LAN cable and the connector 135C.

<Housing 140>
The housing 140 accommodates therein the second antenna 120, the third antennas 130A and 130B, the connectors 135A to 135C, and the signal processing unit 150. The housing 140 is a case for the device main body 101, and is, for example, a box-shaped member. As an example, a part of the connector 135C is exposed on the outer surface of the housing 140.

The housing 140 also has a connector 145. The connector 145 is a connector that allows the transmission cable 115 connected to the first antenna 110 to be detached, and therefore a portion of the connector 145 is exposed on the outer surface of the housing 140.

<Signal Processing Unit 150>
The signal processing unit 150 is connected to the first antenna 110, the second antenna 120, the third antennas 130A and 130B, and the connector 135C. Among these, the signal processing unit 150 is connected to the first antenna 110 and the third antennas 130A and 130B via the connector 145 and the connectors 135A and 135B, respectively.

The signal processing unit 150 amplifies the radio waves of the first frequency received by the first antenna 110 and outputs them to the connector 135A. The radio waves of the first frequency output to the connector 135A are radiated from the third antenna 130A to the interior of the building 1. The signal processing unit 150 converts the frequency of the radio waves of the second frequency received by the second antenna 120 to a wireless LAN frequency, amplifies the frequency, and outputs it to the connector 135B. The wireless LAN radio waves output to the connector 135B are radiated from the third antenna 130B to the interior of the building 1. The signal processing unit 150 also converts the frequency of the radio waves of the second frequency received by the second antenna 120 to a wired LAN frequency, amplifies the frequency, and outputs it to the connector 135C.

In the case of Part 1 and Part 2 of the modified operation of the wireless communication device 100 described above, the signal processing unit 150 performs the operations described in Part 1 and Part 2.

<Circuit configuration of signal processing unit 150>
Fig. 4 is a diagram showing an example of a circuit configuration of the signal processing unit 150 of the wireless communication device 100. In addition to the signal processing unit 150, Fig. 4 shows the first antenna 110, the transmission cable 115, the second antenna 120, the third antennas 130A and 130B, the connectors 135A to 135C, the housing 140, and the connector 145.

The signal processing unit 150 has a wireless module 151, switches 152A, 152B, LNAs (Low Noise Amplifiers) 153A, 153B, ADCs (Analog to Digital Converters) 154A, 154B, DACs (Digital to Analog Converters) 155A, 155B, and PAs (Power Amplifiers) 156A, 156B.

The switch 152A is connected to the first antenna 110 via the transmission cable 115 and the connector 145, and the ADC 154A and the DAC 155A are connected to the switch 152A via the LNA 153A and the PA 156A, respectively. The ADC 154A and the DAC 155A are connected to the wireless module 151. The first antenna 110, the transmission cable 115, the connector 145, the switch 152A, the LNA 153A, the ADC 154A, the DAC 155A, and the PA 156A constitute the wireless communication unit 102A. When the wireless communication device 100 performs MIMO communication using multiple first antennas 110, the number of wireless communication units 102A equal to the number of channels of the MIMO communication is connected to the wireless module 151.

A switch 152B is connected to the second antenna 120, and an ADC 154B and a DAC 155B are connected to the switch 152B via an LNA 153B and a PA 156B, respectively. The ADC 154B and the DAC 155B are connected to the wireless module 151. The second antenna 120, the switch 152B, the LNA 153B, the ADC 154B, the DAC 155B, and the PA 156B constitute the wireless communication unit 102B. When the wireless communication device 100 performs MIMO communication using multiple second antennas 120, a number of wireless communication units 102B equal to the number of channels of the MIMO communication are connected to the wireless module 151.

The wireless module 151 is, for example, configured with an MCU (Micro Controller Unit), and performs switching processing of the switches 152A and 152B, processing for setting the gain of the LNAs 153A, 153B, and the PAs 156A and 156B, and relay processing. The relay processing includes processing for converting the frequency of the radio waves from the first or second frequency to the frequency of a wireless LAN or a wired LAN.

When the wireless module 151 receives radio waves through the first antenna 110 of the wireless communication unit 102A, it switches the three-terminal switch 152A to connect the first antenna 110 to the LNA 153A. When the wireless module 151 transmits radio waves through the first antenna 110, it switches the three-terminal switch 152A to connect the first antenna 110 to the PA 156A. When the wireless module 151 receives or transmits radio waves through the second antenna 120, it similarly switches the three-terminal switch 152B.

LNA 153A is provided between switch 152A and ADC 154A, and amplifies the radio waves received by first antenna 110 and outputs them while preventing degradation of the signal-to-noise ratio. If necessary, a mixer may be provided between LNA 153A and ADC 154A to mix the radio waves output from LNA 153A with a local signal, demodulate the signal, and convert it into an intermediate frequency (IF) signal.

The ADC 154A digitally converts the signal output from the LNA 153A and outputs it to the wireless module 151.

When the wireless communication device 100 transmits a signal from the first antenna 110, the DAC 155A converts the signal output by the wireless module 151 into an analog signal and outputs the analog signal to the PA 156A. If necessary, a mixer may be provided between the DAC 155A and the PA 156A to mix the signal with a local signal and perform modulation.

PA156A amplifies the signal output from DAC155A and outputs it to the first antenna 110 via switch 152A.

In addition, when the wireless module 151 transmits or receives radio waves using the second antenna 120 of the wireless communication unit 102B, it controls the PA 156B via the switch 152B of the wireless communication unit 102B to perform the same processing as that performed for the wireless communication unit 102A.

First Modification of the Embodiment
Fig. 5 is a diagram showing an example of the configuration of a first antenna 110M according to a first modified example of the embodiment. The first antenna 110M according to the first modified example of the embodiment has a substrate 110MA, an antenna element 111M, a feeder line 112, and branch lines 113 and 114M. The first antenna 110M differs from the first antenna 110 shown in Fig. 3 in that it has a substrate 110MA made of a glass plate, an antenna element 111M made of a monopole antenna, and a branch line 114M. The differences from the first antenna 110 shown in Fig. 3 will be described below.

<Substrate 110MA>
The substrate 110MA is a glass plate, and examples of the material that can be used include soda-lime glass, non-alkali glass, Pyrex (registered trademark) glass, and quartz glass. A ground layer 110MG is provided on approximately half of the surface on the +Z direction side of the substrate 110MA on the -Y direction side. The ground layer 110MG is formed, for example, of a mesh-like metal thin film made of copper, nickel, gold, or the like.

<Overall configuration of antenna element 111M, feed line 112, and branch lines 113 and 114M>
As an example, the antenna element 111M, the feed line 112, and the branch lines 113 and 114M are formed of a metal thin film such as copper, nickel, or gold, similar to the ground layer 110MG. Note that the branch line 114M is set to a predetermined resistance value, similar to the branch line 114 of the first antenna 110 shown in Fig. 3, and therefore may be formed of a transparent conductive film such as ITO, which has a higher resistance value than a mesh-shaped metal.

The first antenna 110M has a visual transmittance of 50% or more because the substrate 110MA is transparent to visible light, and the antenna element 111M, the feed line 112, and the branch lines 113 and 114M are made of transparent conductors such as mesh-like metal thin films.

<Antenna element 111M>
The antenna element 111M is, for example, a linear monopole antenna extending along the Y direction in the XY plane (planar view of the first antenna 110M), and extends further in the +Y direction than the ground layer 110MG provided on the surface of the substrate 110MA on the +Z direction side. The antenna element 111M has a feed point 111A at the end on the -Y direction side. The position of the feed point 111A in the Y direction is approximately equal to the position of the end edge extending in the X direction on the +Y direction side of the ground layer 110MG in plan view.

<Branch line 114M>
The branch line 114M branches off from a midpoint 113A in the length of the branch line 113 in the extension direction, and extends, for example, in the -Y direction to a pad 114MA located on the end edge of the substrate 110MA in the -Y direction. In Fig. 5, the branch line 114M is bent between the midpoint 113A and the pad 114MA in order to increase its length. The branch lines 113 and 114M form a choke structure.

Furthermore, the four branch lines 114M of the four first antennas 110M have different resistance values from each other. This is to make the four first antennas 110M identifiable. The branch lines 113 and 114M are an example of a choke structure and an example of an identification portion.

The resistance value of each branch line 114M is an example of a predetermined DC resistance value. As an example, the resistance values of the four branch lines 114M may be set to four different resistance values within a range of 0 Ω to 500 Ω.

A pad 114MA is provided at the end of the branch line 114M in the -Y direction. Because the substrate 110MA is a glass plate, it is not as easy to fabricate a through-hole via as it is with a resin substrate, and the cost is high. For this reason, when using the substrate 110MA made of a glass plate, a connector (not shown) is connected between the pad 114MA and the ground layer 110MG, and the connector is connected to the shielded wire of the coaxial cable used as the transmission cable 115.

As an example, if the four branch lines 114M are made of a mesh-like metal thin film, they may have different resistance values due to differences in mesh density, etc.

Since the resistance values of the four branch lines 114M are different from each other, for example, when the wireless communication device 100 performs MIMO communication or beamforming with the four antenna elements 111M (first antennas 110M), the signal processing unit 150 can identify the four antenna elements 111M (first antennas 110M). This is because the signal processing unit 150 is connected to the antenna elements 111M and the ground layer 110MG of the substrate 110MA via the transmission cable 115. Note that, as an example, when the wireless communication device 100 does not perform MIMO communication or beamforming with the four antenna elements 111M (first antennas 110M), the resistance values of the four branch lines 114M may be equal to each other.

In addition, in both cases where the resistance values of the four branch lines 114M are different from one another and where the resistance values of the four branch lines 114M are equal to one another, the signal processing unit 150 can identify the attachment/detachment state of the four first antennas 110M to the four connectors 145. The branch lines 114M function as an identification unit.

<Second Modification of the Embodiment>
6 is a diagram showing an example of the configuration of a wireless communication device 100M according to a second modified example of the embodiment. The wireless communication device 100M shown in FIG. 6 includes two sets of the first antenna 110, the transmission cable 115, the matching layer 117, and the liquid crystal phase shifter 118 shown in FIG. 1. As described with reference to FIGS. 1 to 4, one set includes four first antennas 110. Therefore, the wireless communication device 100M shown in FIG. 6 includes two sets of four first antennas 110. That is, the wireless communication device 100M includes two sets of eight first antennas 110. The wireless communication device 100M may include three or more sets of the first antenna 110, the transmission cable 115, the matching layer 117, and the liquid crystal phase shifter 118.

Such a wireless communication device 100M can perform, for example, eight-channel MIMO communication at two types of first frequencies, beamforming to form two beams at two types of first frequencies, etc. If the wireless communication device 100M includes three or more sets of the first antenna 110, transmission cable 115, matching layer 117, and liquid crystal phase shifter 118, the number of channels and beams of MIMO communication can be further increased.

Furthermore, the first antennas 110 of some of the multiple sets may constitute an array antenna that communicates at a first frequency of 10 GHz or less, and the first antennas 110 of some of the other multiple sets may constitute a phased array antenna that communicates at a first frequency of 25 GHz or more. In this case, beamforming can be performed by using the antenna elements 111 included in the first antennas 110 of some of the other multiple sets as a phased array antenna.

＜Effects＞
The wireless communication device 100 includes a signal processing unit 150, a housing 140 that houses the signal processing unit 150, a first antenna 110 that is provided outside the housing 140 and connected to the signal processing unit 150 via a transmission cable 115, and communicates with a base station BS1 using radio waves of a first frequency, a second antenna 120 that is provided inside the housing 140 or on the outer surface of the housing 140, connected to the signal processing unit 150, and communicates with a base station BS2 using radio waves of a second frequency lower than the first frequency, and connectors (135A to 135C) that are provided inside the housing 140 or on the outer surface of the housing 140, connected to the signal processing unit 150, and input and output communication data transmitted and received by the first antenna 110 or the second antenna 120. Since the first antenna 110 is not provided inside the housing 140, the device body 101 and the housing 140 can be made smaller.

As a result, it is possible to provide a wireless communication device 100 that is compact and capable of communicating with a base station at multiple frequencies.

It may further include a third antenna 130A or 130B connected to the connector (135A or 135B). Therefore, communication data transmitted and received by the first antenna 110 or the second antenna 120 can be radiated from the third antenna 130A or 130B connected to the connector (135A or 135B). Radio waves of the first or second frequency can be relayed to a terminal such as a smartphone 50 or a PC that can receive the radio waves radiated by the third antenna 130A or 130B.

The first antenna 110 may also be installed within the line of sight of the window 10 near the indoor window 10. In cases where radio waves of the first frequency pass through the window glass 11 without passing through the wall 1W of the building 1, installing the first antenna 110 within the line of sight of the window 10 ensures that communication using radio waves of the first frequency can be performed between the outdoor base station (BS1 or BS2) and the first antenna 110. The second antenna 120 may also be placed in a position that is not within the line of sight of the window 10. This allows for a high degree of freedom in the location where the housing 140 is placed.

The first antenna 110 may also have a visual transmittance of 50% or more. When the first antenna 110 is provided on the window glass 11, this can prevent the visibility from being impaired and allow more visible light to enter the room through the window glass 11.

In addition, the transmission cable 115 may be detachable from the housing 140. Since the transmission cable 115 can be detached from the housing 140, the first antenna 110 can be easily attached to the window glass 11, and the housing 140 can be easily installed. In addition, the first antenna 110 can be easily replaced.

The first antenna 110 may also have an identification unit (113, 114) that allows the signal processing unit 150 to identify whether the first antenna 110 is attached to or detached from the housing 140. The signal processing unit 150 can identify whether the first antenna 110 is connected to the signal processing unit 150 or not based on the identification unit.

Furthermore, the system may include a plurality of first antennas 110, and the identification units (113, 114) of the plurality of first antennas 110 may be different from each other. For example, when performing MIMO communication or beamforming, the signal processing unit 150 can easily identify the plurality of first antennas 110.

The first antenna 110 may have an antenna element 111 and a choke structure (113, 114) connected to the antenna element 111, and the identification portion (113, 114) may be the choke structure (113, 114). The choke structure is invisible in terms of AC, so it is possible to make the first antenna 110 identifiable without affecting the antenna characteristics of the first antenna 110.

The first antenna 110 further includes a feed line 112 connected to the antenna element 111, and if the electrical length of the wavelength at the communication frequency of the first antenna 110 is λe, the choke structure (113, 114) may include a branch line 113 that branches off from the feed line 112 and has a length of λe/2, and a branch line 114 that branches off from the midpoint of the length of the branch line 113 and has a predetermined DC resistance value. The choke structure including the branch lines 113 and 114 is not visible from the feed line 112 or ground in terms of AC, so that the first antenna 110 can be made identifiable without affecting the antenna characteristics of the first antenna 110.

The specified DC resistance value may be between 0 Ω and 500 Ω. A DC resistance value between 0 Ω and 500 Ω allows the first antenna 110 to be reliably identified. Also, it allows easy determination as to whether the first antenna 110 is connected.

Furthermore, a plurality of first antennas 110 or second antennas 120 may be included. A wireless communication device 100 capable of implementing MIMO communication, beamforming, etc. can be provided.

The antenna may further include a matching layer 117 provided between the first antenna 110 and the window 10. When the first antenna 110 transmits and receives radio waves, the electrical length of the radio waves passing through the window glass 11 is adjusted to match the impedance, thereby reducing loss.

The multiple first antennas 110 may also be phased array antennas. This provides a wireless communication device 100 capable of implementing beamforming and the like.

The phased array antenna may also be a phased array antenna having a liquid crystal phase shifter. A wireless communication device 100 can be provided that can adjust the phase with the liquid crystal phase shifter to achieve beamforming, etc.

The first frequency is equal to or higher than a predetermined frequency, and the second frequency is lower than the predetermined frequency, which may be equal to or higher than 1 GHz and equal to or lower than 3 GHz. By setting an appropriate predetermined frequency according to the structure of the wall 1W of the building 1, it is possible to provide a wireless communication device 100 that can transmit and receive radio waves of the first frequency that pass through the window glass 11 using the first antenna 110, and can transmit and receive radio waves of the second frequency that pass through the wall 1W using the second antenna 120.

The second antenna 120 may also be an inverted F antenna. By making the second antenna 120 a broadband inverted F antenna, radio waves at the second frequency can be transmitted and received over a broadband even if the second antenna 120 is provided inside the housing 140 or on the outer surface of the housing 140.

The first antenna 110 may also be adhered to the window glass 11 of the window 10. By adhering the first antenna 110 to the window glass 11, the first antenna 110 can be stably installed in the line of sight area of the window 10, and radio waves of the first frequency can be stably transmitted and received.

Furthermore, the wireless communication device 100 may include a plurality of sets of the first antenna 110 and the transmission cable 115, and some of the first antennas 110 of the plurality of sets may constitute an array antenna that communicates at a first frequency of 10 GHz or less, and some of the other of the plurality of sets may constitute a phased array antenna that communicates at a first frequency of 25 GHz or more. It is possible to provide a wireless communication device 100 that transmits and receives radio waves of a relatively low first frequency using an array antenna, and can perform beamforming on radio waves of a relatively high first frequency using a phased array antenna. By performing beamforming on radio waves of a relatively high first frequency, it is possible to improve the gain and improve the performance of the wireless communication device 100. Radio waves can be transmitted and received under optimal conditions depending on the frequency levels of the plurality of first frequencies and the characteristics of the radio waves of each first frequency, such as the linearity.

The above describes an exemplary wireless communication device of the present disclosure, but the present disclosure is not limited to the specifically disclosed embodiments, and various modifications and variations are possible without departing from the scope of the claims.

This international application claims priority to Japanese Patent Application No. 2023-020790, filed on February 14, 2023, the entire contents of which are incorporated herein by reference.

1 Building 1W Wall 10 Window 11 Window glass 50 Smartphone 100, 100M Wireless communication device 101 Device main body 102A, 102B Wireless communication unit 110, 110M First antenna 110A, 110MA Substrate 110MG Ground layer 111, 111M Antenna element 111A Power supply point 112 Power supply line 113, 114, branch line Branch line (identification unit, an example of a choke structure)
113A: midpoint 114A, 114MA: pad 115: transmission cable 117: matching layer 118: liquid crystal phase shifter 120: second antenna 130A, 130B: third antenna 135A to 135C: connector (an example of an input/output terminal)
140: Housing 145: Connector 150: Signal processing unit 151: Wireless module 152A, 152B: Switch 153A, 153B: LNA
154A, 154B ADC
155A, 155B DAC
156A, 156B PA

Claims (18)

1. A signal processing unit;
   A housing that houses the signal processing unit;
   a first antenna provided outside the housing, connected to the signal processing unit via a transmission cable, and configured to communicate with a base station using radio waves of a first frequency;
   a second antenna provided within the housing or on an outer surface of the housing, connected to the signal processing unit, and configured to communicate with the base station using radio waves having a second frequency that is lower than the first frequency;
   an input/output terminal provided within the housing or on an outer surface of the housing, connected to the signal processing unit, and performing input/output of communication data transmitted and received by the first antenna or the second antenna.
2. The wireless communication device of claim 1, further comprising a third antenna connected to the input/output terminal.
3. The wireless communication device according to claim 1 or 2, wherein the first antenna is installed in the vicinity of an indoor window and within the line of sight of the window.
4. The wireless communication device according to any one of claims 1 to 3, wherein the first antenna has a visual transmittance of 50% or more.
5. The wireless communication device according to any one of claims 1 to 4, wherein the transmission cable is detachable from the housing.
6. The wireless communication device according to any one of claims 1 to 5, wherein the first antenna has an identification unit that enables the signal processing unit to identify whether the first antenna is attached to or detached from the housing.
7. The first antenna includes a plurality of first antennas,
   The wireless communication device according to claim 6 , wherein the identification portions of the plurality of first antennas are different from one another.
8. The first antenna is
   an antenna element; and a choke structure connected to the antenna element;
   The wireless communication device according to claim 7 , wherein the identification portion is the choke structure.
9. The first antenna further includes a feed line connected to the antenna element,
   If the electrical length of the wavelength of the first antenna at the communication frequency is λe, then
   The choke structure includes:
   A first branch line branching off from the feed line and having a length of λe/2;
   The wireless communication device according to claim 8 , further comprising: a second branch line branching off from a midpoint of the length of the first branch line and having a predetermined DC resistance value.
10. The wireless communication device according to claim 9, wherein the predetermined DC resistance value is between 0 Ω and 500 Ω.
11. The wireless communication device according to any one of claims 1 to 10, comprising a plurality of the first antennas or the second antennas.
12. The wireless communication device of claim 3, further comprising a matching layer disposed between the first antenna and the window.
13. The wireless communication device according to claim 11, wherein the first antennas are phased array antennas.
14. The wireless communication device according to claim 13, wherein the phased array antenna is a phased array antenna having a liquid crystal phase shifter.
15. the first frequency is equal to or greater than a predetermined frequency, and the second frequency is less than the predetermined frequency,
    The wireless communication device according to claim 1 , wherein the predetermined frequency is equal to or higher than 1 GHz and equal to or lower than 3 GHz.
16. The wireless communication device according to any one of claims 1 to 15, wherein the second antenna is an inverted F antenna.
17. The wireless communication device according to claim 3, wherein the first antenna is attached to the window glass of the window.
18. a plurality of pairs of the first antenna and the transmission cable;
    the first antennas of some of the plurality of sets constitute an array antenna that communicates at the first frequency of 10 GHz or less;
    The wireless communication device according to claim 1 , wherein the first antennas of other of the plurality of sets constitute a phased array antenna that communicates at the first frequency of 25 GHz or higher.

Images