JPH03182103A - Phased array antenna - Google Patents

Abstract

PURPOSE:To make an antenna thin as a whole by respectively constituting feeding circuit such as a phase shifter, a distributor, and driving circuit on the same surface of a substrate, and laminating them together with a plane- shaped antenna element. CONSTITUTION:A phased array antenna is composed of an antenna layer, which is composed of 16 radiating element conductors 14 arranged at rectangular lattice positions on a dielectric substrate 12, and a feeding circuit layer composed of 16 phase shifters 22, which are arranged on the back of the dielectric substrate 20 corresponding to the respective radiating element conductors 14, and the distributor. the antenna layer and the feeding circuit layer are adhered with a ground conductor board 16 between. In the lower direction of the feeding circuit layer, a drive circuit layer is provided through an air layer 70 while being composed of a driving circuit 34, which is arranged on the surface of a circuit board 30 corresponding to the respective phase shifters 22 on the dielectric substrate 20, and a control line 32 and these antenna layer, feeding circuit layer and driving circuit layer are laminated in this order. Thus, the device can be made thin as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a phased array antenna whose beam direction can be electronically scanned, and particularly to its thinning.

[Background Art] With the rapid progress of electronic communication technology in recent years, radio communication has come to be used in various fields. Under these circumstances, mobile communications such as car telephones are attracting attention as transmitters and receivers become smaller.

In mobile communication, there is a method in which a plurality of base stations are provided on the ground and communication with mobile objects is carried out within the area under the jurisdiction of these base stations, and this method is used in automobile telephones and the like. However, in such a communication system that uses terrestrial base stations, the communicable range is limited because an unlimited number of base stations cannot be provided.

On the other hand, mobile communications using satellites do not have such restrictions and can provide high-quality services over a wide range, so studies are underway in various fields to put them into practical use.

Here, an antenna for mounting on a mobile object is extremely important. This is because if the antenna cannot transmit and receive well, no matter how sophisticated the other transmitting and receiving equipment is, good communication cannot be achieved.

As a moving object such as a car moves, its relative position with respect to a satellite etc. changes as the object moves, so it is necessary to change the direction of transmission and reception according to the driving situation. Therefore,
BACKGROUND ART Conventionally, antennas for mobile objects that can control the pointing direction have been employed. In particular, for mobile objects such as automobiles, it is necessary to be small and lightweight, and to be able to track satellites etc. in response to the violent movement of the automobile, and we believe that a phased array antenna that can electronically scan the beam is suitable. It is being

Here, a basic configuration example of a phased array antenna will be explained based on the drawings.

FIG. 10 is a schematic configuration diagram showing an example of a conventional phased array antenna, which has n antenna elements A1 to An that convert radio waves and current. Corresponding to these antenna elements AI-An, n phase shifters iBl to Bn that change the phase of the high frequency current fed thereto are connected. Further, each of the phase shifters B1 to Bn is connected to a distributor C that distributes or bases high frequency power and a drive circuit that drives the phase shifters B1 to Bn.

In the phased array antenna, the directivity (beam) of the antenna can be changed by controlling the amount of phase shift of each of the plurality of phase shifters 81 to an by a drive circuit.

In this way, phased array antennas can scan beams electronically at high speed, making them useful for ships, aircraft,
It is thought to have characteristics suitable for antennas for radar and satellite communication in moving objects such as trains and automobiles.

[Problems to be Solved by the Invention] As described above, the conventional phased array antenna achieves a thin structure by employing a microstrip antenna as the antenna element A. but,
Since a phased array antenna includes not only the antenna element A, but also a phase shifter B, a distributor C, and a drive circuit, it is difficult to make the entire antenna smaller and thinner, including these elements, and it is difficult to install it in a small moving object such as a car. The problem was that it was difficult to Alternatively, a method such as arranging the antenna element and the feeding circuit separately may be considered, but such a configuration poses problems such as complicating the connection between the antenna element and the feeding circuit, and is difficult to realize in practice.

Therefore, it is necessary to reduce the size and thickness of the structure including the antenna element, feeder circuit, drive circuit, etc.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a phased array antenna with a thin structure.

[Means for Solving the Problems] A phased array antenna according to the present invention includes an antenna layer provided on a dielectric substrate and having a plurality of radiating element conductors, and a strip line connected to each of the plurality of radiating element conductors. A power supply circuit layer having a power supply circuit including a phase shifter and a distributor formed of conductors, and a drive circuit having a drive circuit connected to the power supply circuit and supplying a signal for controlling the amount of phase shift in the phase shifter. The antenna layer is characterized by having a structure in which the antenna layer, the feeder circuit layer, and the drive circuit layer are laminated.

In this way, in the present invention, the power supply circuit and the drive circuit such as a phase shifter and a divider are respectively configured on the same surface of the substrate, and by stacking them together with the planar antenna element, it is possible to Compared to phased array antennas, the entire antenna is extremely thin.

[Function] The phased array antenna according to the present invention has the above-described configuration, and the high frequency current supplied via the distributor is transmitted by a plurality of phase shifters whose phase shift amount is set by a drive circuit. It is set to a predetermined phase and is supplied to each corresponding radiating element conductor. Therefore, radio waves with a predetermined phase are transmitted from the radiating element conductor. Note that during reception, the high frequency Tli currents obtained by the radiating element conductor can be combined into the same phase through the opposite path.

[Effects of the Invention] As explained above, according to the phased array antenna according to the present invention, since each component is laminated in a layered structure, the device as a whole can be made thinner, and can be mounted on a moving body such as a vehicle, and can be mounted on a mobile object such as a satellite. be able to communicate effectively with

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

Example 1 FIG. 1 is a perspective view showing the structure of a phased array antenna of Example 1, and FIG. 2 is a sectional view thereof.

As shown in FIG. 1, the phased array antenna of this embodiment has 16 antenna elements arranged in a square grid on a dielectric substrate 12.
The antenna jφ consists of 16 radiating element conductors 14, and a feeding circuit layer consisting of 16 phase shifters 22 and distributors 24 arranged on the back surface of the dielectric substrate 20 corresponding to each radiating element conductor 14. ing. Then, as shown in FIG. 2, the antenna layer and the feeder circuit layer sandwich the ground conductor plate 16,
It's in close contact. Each phase shifter 2 on the dielectric substrate 20 is attached to the surface of the circuit board 30 via an air layer 70 below the power supply circuit layer.
Drive circuit 34 and control line 32 arranged corresponding to 2
The antenna layer, the feeder circuit layer, and the drive layer are stacked in the above order.

In this embodiment, 16 radiating element conductors 14 are provided, and they are arranged in a square grid position as shown in FIG. However, the present invention is effective for a phased array antenna in which antenna elements are arranged at arbitrary positions on a plane.

Next, each of the above-mentioned configurations will be explained in more detail.

The antenna layer is a radiating element conductor 1 formed by etching or other means on a copper-clad dielectric substrate on one surface of a dielectric substrate 12.
4 and is laminated on the ground conductor plate 16.

The feeder circuit layer includes a phase shifter 22 and a distributor 24 formed on one surface of a dielectric substrate 20 using a plurality of strip line conductors. In this example, the feed circuit layer is configured such that a dielectric substrate 12 forming the antenna layer and a dielectric substrate 20 forming the feed circuit layer are in close contact with each other with a ground conductor plate 16 in between.

Here, in order to make the entire antenna thinner, the feeder circuit especially needs to be small and thin, and the way it is arranged is important. In the present invention, as shown in FIG. 1, a power supply circuit is constructed of a strip line conductor or the like on a dielectric substrate 20, and
The distributor 24 is disposed on the same surface between the phase shifters 22, and the power supply circuit is integrated into an integrated structure, thereby achieving a thinner power supply circuit.

In addition, the arrangement of the feeding circuit is such that the phase shifter 22 is arranged directly below the radiating element conductor 14, and the dielectric substrate 12 forming the antenna layer is
The dielectric substrate 20 forming the power supply circuit layer and the power supply circuit layer share the ground conductor plate 16 and are bonded together, thereby achieving a thinner structure.

Note that since these two layers share the ground conductor plate 16, the radiating element conductor 14 and one end of the phase shifter 22 are coupled by the feed pin 26 to supply a high frequency signal to the antenna.

Next, the configurations of the phase shifter 22 and the distributor 24 will be explained.

Each phase shifter 22 includes a strip line conductor 50, a PIN diode 51, and a PIN diode 51 as shown in FIG.
Bias line 52 and drive circuit 34 for control of
and a connector 36b for connection. Such a phase shifter is called a line-switched phase shifter. And the PIN
The diode 51 performs a switching operation by the bias current supplied through the bias line 52.

The operation of the line switching type phase shifter will be explained with reference to FIG. This phase shifter connects strip lines with different lengths LL and L2 to P
Switching is performed by passing a bias current through the IN diode, and the phase is changed according to the line difference LL-L2. The phase shift difference φ0 at this time is expressed as φ−360X (LL−L2 j /λ), where λ is the wavelength used.

In this embodiment, as shown in Fig. 6, the line difference is 45'', 9
0″, 180″, and three line switching type phase shifters 5
4,55,56 are connected in cascade, and a 3-bit phase shifter that changes every 45'' in 360° is used.The number of bits of this phase shifter is related to the fineness with which the beam is scanned. As the number of bits increases, the structure becomes more complex, but the beam can be scanned in a correspondingly finer manner.

Although a line-switching phase shifter was used in this example, it is also possible to use a line-switching phase shifter or a hybrid phase shifter that can be made smaller and thinner using a dielectric substrate. Good too.

Next, the structure of the distributor is shown in FIG. The distributor 24 is made of a strip line conductor formed on the dielectric substrate 20, and the high frequency signal is distributed from the input/output terminal 60 to 11 locations (2
Finally, the signal is divided into 16 parts by the branching branch) and inputted to each phase shifter 22. Furthermore, the high frequency signal is outputted to the outside by attaching a coaxial connector 61 to the input/output end 60 and connecting it to a coaxial line. At this time, the inner conductor of the coaxial connector 61 is connected to the distributor 24, and the outer conductor is connected to the ground conductor plate 16.

As for the overall operation, the high frequency signal inputted to the divider 24 is divided into 16 parts and outputted to each phase shifter 22. Then, the amount of phase shift is changed by each phase shifter 22 according to the direction of the beam, and the beam is supplied to each radiating element conductor 14 via a power supply bin 26, from which it is transmitted as a radio wave.

Although the explanation has been given above mainly regarding transmission, the phased array antenna of the present invention operates in the same manner regarding reception, except that the path is reversed.

On the other hand, a drive circuit layer is arranged below the power supply circuit layer with an air layer 70 in between. The drive circuit layer is formed on the circuit board 30 by a drive circuit 34 for operating the PIN diode in the phase shifter 22 and a control line 32 for controlling the drive circuit 34. Here, the air layer 70 is required to be 10 mm and 15 degrees so that the characteristics of the power supply circuit layer are not deteriorated due to the proximity of the drive circuit layer.

The connection between the phase shifters 22 and the drive circuits 34 is as shown in FIG.
4 is arranged and connected via the connector 36a on the drive circuit 34 of 24(I and the connector 36b on the phase shifter 22. A cross-sectional view thereof is shown in FIG. 3. Each drive circuit 3
4 is connected to a control line 32, and the control line 32 is connected to an external control device via three connectors.

On the other hand, all of the drive circuits 34 are connected to a control device 90, as shown in FIG.
A command signal from is input to each drive circuit 34 via a connector 39. The connector 36 is connected between the drive circuit 34 and the phase shifter 22 by a total of six control lines, two each corresponding to the (45°) bit 54, (90o) bit 55, and (180") bit 56. A bias current is applied to the PIN diode 51 on the phase shifter 22 to control the phase shift amount of the phase shifter 22 and change the beam direction.

As described above, in the phased array antenna of the present invention, each element (antenna element A1 phase shifter B1 distributor C1 drive circuit D) is made thin and these are stacked and connected as described above, so the phased array antenna can be made very thin.

Example 2 A schematic cross-sectional view of Example 2 is shown in FIG.

In the first embodiment, the feeder circuit layer has a structure in which a strip line conductor is formed on one side of the dielectric substrate 20. On the other hand, in the second embodiment, the feeder circuit layer is composed of a phase shifter 22 and a distributor 24 formed of a line conductor or the like in a dielectric substrate 20.

The dielectric substrate 20 includes two ground conductor plates 16 and 4.
It has a structure in which it is tightly sandwiched between the two. Note that the other structures are the same as in the first embodiment.

In Example 1, the characteristics of the power supply circuit deteriorate due to the proximity of the drive circuit layer, so there is an air layer 7 of about 10 mm.
0 was needed. In contrast, in the structure of Example 2, the characteristics of the power supply circuit are not affected even when the drive circuit layer approaches. Therefore, the distance between the air layer 70 between the power supply circuit layer and the drive circuit layer can be narrowed. With this structure, the connector 36 that connects the phase shifter 22 and the drive circuit 34 can be shortened, and the thickness of the phased array antenna can be made even thinner than in the first embodiment.

In addition, in the second embodiment, as in the first embodiment, the connector 36 is divided into two connectors 36g and 36 as shown in FIG.
If it is divided into two parts and connected by plug-in type, the power supply circuit and drive circuit can be easily attached and detached.

Example 3 A schematic cross-sectional view of Example 3 is shown in FIG.

This third embodiment is characterized in that, in the configuration of the second embodiment described above, components of the drive circuit layer are mounted on the surface opposite to the power supply circuit layer 20. That is, a drive circuit layer 34 and a control line 32 are formed on the lower surface of the circuit board 30. Then, the phase shifter 22 and the drive circuit 34 are connected to the bin 38.
connected by.

As a result, an air layer 7 between the power supply circuit layer and the drive circuit layer
0 is eliminated, allowing two layers to be placed in close contact with each other. Therefore, the entire phased array antenna can be made thinner than ever before. Furthermore, in this example, there is no air layer 70 at all, and there is no need to connect with the connector 36 or the like, which increases the strength of the antenna and improves its earthquake resistance when mounted on a moving body or the like.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the phased array antenna of the first embodiment, Fig. 2 is a schematic sectional view showing the structure of the phased array antenna of the first embodiment, and Fig. 3 is a phase shifter of the first embodiment. 4 is a schematic sectional view showing the structure of the phased array antenna of Example 2; FIG. 5 is a schematic sectional view showing the structure of the phased array antenna of Example 3; Figure 6 is a perspective view showing the configuration of the phase shifter, Figure 7 is an explanatory diagram showing the operation of the phase shifter, Figure 8 is a perspective view showing the configuration of the distributor, and Figure 9 shows the connection relationship of the drive circuit. Explanatory diagram showing, No. 10
The figure is a schematic configuration diagram showing the configuration of a conventional example. ... Distributor 30 ... Circuit board 32 ... Control line 34 ... Drive circuit 36.36a, 36b, 39 - ... Connector 8 0 1 2 0 0 0 Inner conductor strip line conductor PIN of connector 36 Diode bias line coaxial connector air layer control device

Claims (2)

[Claims] (1) An antenna layer having a plurality of radiating element conductors provided on a ground conductor plate via a dielectric substrate; and an antenna layer each connected to the plurality of radiating element conductors and provided on the ground conductor plate via a dielectric substrate. A power supply circuit layer is formed of a power supply circuit consisting of a phase shifter and a distributor formed by a plurality of strip wire conductors, and a power supply circuit layer is connected to the phase shifter of this power supply circuit and transmits a signal for controlling the amount of phase shift. 1. A phased array antenna comprising: a drive circuit layer having a drive circuit to be supplied; (2) In the phased array antenna according to claim (1) above, the feeder circuit consisting of a phase shifter and a divider is formed by a plurality of line conductors in a dielectric substrate sandwiched between two ground conductor plates. A phased array antenna characterized by: