JPH0936630A - Antenna for portable radio device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna which can be used for a radio device using a high frequency radio wave of the ultrashort band or higher and is easily structured and produced and is formed to a small and thin size. SOLUTION: A dipole antenna is incorporated in band parts 2a and 2b, and a loading coil (inductance) is loaded on the side of feed terminals 7a and 7b of the dipole antenna. Therefore, the effective length of the antenna can be extended equivalently to actual dimensions of the antenna without reducing the efficiency or the gain for the wavelength of the radio wave having a desired tuning frequency, and the antenna can be minizturized. The structure and production of a buckle part 3 are simplified to easily produce the antenna since a loop is not constituted through the buckle part 3, and the antenna length is not changed to improve antenna characteristics and the sensitivity, the performance, and the stability of the radio device since the antenna is not affected by the thickness or the like of user's arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio device antenna for transmission / reception in a wristwatch-type radio broadcast receiver, transceiver, mobile phone, radio calling terminal, communication device and the like.

[0002]

2. Description of the Related Art Heretofore, various types of portable radio equipment having a size as small as a wristwatch have been proposed because of their small size, light weight and excellent portability. Since this portable wireless device is used by being worn on the wrist like a wristwatch, the antenna antenna section for receiving or transmitting radio waves is desired to be miniaturized due to the restrictions on the shape and size thereof. Was there.

Due to the progress of integrated circuit technology, the miniaturization and low power consumption of the radio circuit portion are rapidly progressing, and the small battery or rechargeable battery used as a power source is also small, high performance and high capacity. On the other hand, the miniaturization of antennas has made it possible to reduce the power that can be extracted by the area that the radio wave crosses, and the length of the antenna that is closely related to the tuning detection performance with the wavelength of the radio wave. This is because it was difficult to realize because it was limited by the size.

Therefore, for example, in a wristwatch type wireless device having a limited size, a bar antenna or the like is conventionally used by being built in a case for an AM radio receiver or the like for medium frequency band (MF) radio waves. In a very high frequency (VHF) band FM radio, a wireless calling terminal (pager), etc., a string type antenna that also serves as an earphone or a loop type band antenna that uses the band portion of a wristwatch is used.

[0005]

However, in the above-mentioned conventional antenna for portable radio equipment, since the bar antenna, the string type antenna, and the loop type band antenna are used, there are the following problems. (A) A bar with a built-in case for wristwatch-type wireless devices
For antennas, etc., in recent years, several hundred MHz band, and even several GH
A desired performance cannot be obtained in a radio calling terminal, a mobile phone, and a portable information device with a wireless communication device, which have higher frequencies in the z band. Also, in order to build it in the case part,
There is a problem that it is necessary to avoid using a conductive material such as metal as the case material.

(B) In the case of a string-shaped antenna that also serves as an earphone, such as an FM radio receiver, it may be attached at the time of use,
It had to be rolled out, and there was a problem in terms of usability and form. (C) Further, in the loop type band antenna, in order to form a loop, the loop is formed when the antenna is connected at the buckle part of the arm band, so that the structure and manufacturing are complicated, and the antenna There was a problem that the cost of the department would increase. Also, in such a method,
Not only can it be used when worn on the arm, but the size of the loop antenna changes depending on the size of the arm, and the antenna length also changes.
It was necessary to provide a separate adjustment circuit to compensate for changes in antenna length.

(D) In a wristwatch-type portable wireless device, even if a metal conductor is attached to a band portion to be worn on an arm, there are dimensional restrictions and a conductor in the antenna loop.
Or because the human body's arm, which is an object close to a dielectric, enters
There is a problem in that the characteristics become unstable and desired reception sensitivity and stable reception and communication cannot be performed. (E) Moreover, in general, with loop antennas,
The ratio of the radiation resistance to the input resistance is small, and it is necessary to cancel the input reactance and use it.
There was a problem that the antenna system had to be used in a state of extremely poor efficiency.

Therefore, the present invention can be applied to a radio device using high frequency radio waves in the ultra-high frequency band or higher, and since it is not necessary to form a loop, the structure and the manufacturing can be facilitated and the device can be formed to be small and thin. It is an object of the present invention to provide an antenna for a portable wireless device capable of performing the above.

[0009]

In order to achieve the above object, an antenna for a portable wireless device according to the invention of claim 1 is used as an antenna of a portable wireless device worn by a user by a band portion provided on a main body. In the antenna for portable radio equipment used, the band portion is a conductor having plasticity and is fed from the center point so that the distribution of the current flowing in the conductor in the longitudinal direction is symmetrical with respect to the center point. A power feeding antenna element is provided, and an inductive impedance is loaded at a power feeding end portion of the power feeding antenna element.

According to a second aspect of the present invention, there is provided a portable wireless device antenna according to claim 2, wherein the band portion provided on the main body is used as an antenna of the portable wireless device worn by a user. The band portion is a conductor having plasticity, and is provided with a feeding antenna element fed from the center point so that the distribution of the current flowing in the longitudinal direction of the conductor is symmetrical with respect to the center point.
It is characterized in that a capacitive impedance is loaded on an outer end portion of the feeding antenna element.

Further, the antenna for portable radio equipment according to a third aspect of the present invention is a plastic antenna for a portable radio equipment used as an antenna of a portable radio equipment worn by a user by a band portion provided on the main body. And a feeding antenna element provided in the band portion, the feeding antenna element being fed from the center point such that the distribution of the current flowing in the longitudinal direction of the conductor is symmetrical with respect to the center point. Elements are provided side by side with a parasitic antenna element that is not fed, provided with a parasitic antenna element that is not fed, and by bringing the outer end portion of the feeding antenna element close to the parasitic antenna element side, the outer end portion of the feeding antenna element is provided. It is characterized by loading capacitive impedance.

According to a fourth aspect of the present invention, there is provided a portable wireless device antenna according to the invention, wherein the band portion provided on the main body is used as an antenna of the portable wireless device worn by a user. The band portion is a conductor having plasticity, and is composed of a feeding antenna element plate and a ground plate that sandwich a dielectric from both sides of the front and back sides of the band portion, and the feeding antenna element plate and the outer end portions of the ground plate are adjacent to each other. An inverted F-type antenna that is electrically short-circuited, and the outer end portion of the feeding antenna element plate is bent toward the ground plate side and brought close to each other, and a capacitive impedance is loaded on the outer end portion of the feeding antenna element plate. It is characterized by having done.

According to a fifth aspect of the present invention, there is provided a portable radio device antenna according to the invention, wherein the band portion provided on the main body is used as an antenna of the mobile radio device worn by a user. The band portion is a conductor having plasticity, and is composed of a feeding antenna element plate and a ground plate that sandwich a dielectric from both sides of the front and back sides of the band portion, and the feeding antenna element plate and the outer end portions of the ground plate are adjacent to each other. Is disposed in the feeding antenna element plate, and a plurality of slit-shaped notches having a predetermined length are provided at equal intervals in the feeding antenna element plate, whereby the feeding antenna element plate is provided. , The reactance element and the resistance component are equivalently loaded.

According to a sixth aspect of the present invention, there is provided a portable radio device antenna according to the invention, wherein the band portion provided on the main body is used as an antenna of the mobile radio device worn by a user. It is composed of a loop element made of a conductor having plasticity disposed in the band portion, a tap terminal is provided in the middle of the outer end side of the loop element, and one outer end of the loop element and the tap terminal are feeding terminals. On the other hand, one outer end of the loop element and the other outer end of the loop element are connected by a variable capacitance element, and a plurality of slit-shaped cuts of a predetermined length are provided at equal intervals in the middle of the loop element. Thus, when the loop element is equivalently loaded with the reactance element and the resistance component and the band portion is in a loop state, it acts as an L tap type loop antenna. On the other hand, when the band portion in the open state, characterized in that acting as a reverse F type antenna.

In the present invention, a feeding antenna element made of a conductor having plasticity is provided in the band portion, and the feeding end portion of the feeding antenna element is loaded with inductive impedance, or the outer end portion thereof is capacitive impedance. Is used as a transmitting and receiving antenna. Therefore, the effective length of the antenna can be increased equivalently to the actual size of the antenna without lowering the efficiency or the gain with respect to the wavelength of the radio wave of the desired tuning frequency, and the size can be reduced. .

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described with reference to the drawings, using a wristwatch type wireless device to which an antenna for a portable wireless device is applied as an example.

A. Principle of the Present Invention Generally, in a linear antenna such as a half-wavelength dipole antenna or a quarter-wavelength monopole antenna that operates by receiving an electric field component of a radio wave, a voltage distribution as shown in FIG. Produce a current distribution. For example, in the half-wavelength antenna shown in FIG. 1A, the current distribution has a maximum sine waveform at the center and a sine waveform of "0" at the outer end. On the other hand, the voltage distribution is, on the contrary, a sine waveform having a maximum value of "0" at the central portion and +/- at the outer end portion. Here, the voltage at the center is "0"
1/4 is a quarter-wave monopole antenna shown in FIG. 1 (b). In addition, FIG.
It is a conceptual diagram which shows the electric current distribution and voltage distribution of a 4-wavelength inverted F type antenna.

The input impedance of these linear antennas is such that the antenna length (L) is short with respect to the wavelength λ of the radio wave to be tuned such as λ / 2 and λ / 4 (for example, a wristwatch type antenna is miniaturized. 2)
As shown in (b), the reactance component of the input impedance becomes negative (-) and has a capacitive impedance (capacitance). On the other hand, when the antenna length (L) is long with respect to the wavelength λ, the reactance component becomes positive (+) and has an inductive impedance (inductance).

On the contrary, when the antenna length (L) is fixed, when a radio wave of a frequency (f <f ₀ ) lower than the frequency f _{0 of the} tuning radio wave is received, the wavelength λ is received.
Is longer than λ ₀ , the antenna length (L) is relatively short with respect to the wavelength λ, so the input reactance becomes negative (−), and the capacitive impedance (capacitance) appears. become. On the other hand, high frequency (f> f
On the contrary, when the radio wave of ₀ ) is received, its wavelength λ is λ ₀
Since the antenna length (L) is relatively long with respect to the wavelength λ, the input reactance becomes positive (+) and has an inductive impedance (inductance).

Here, when considering an ultra-compact radio device such as a wrist watch type, it is generally necessary to miniaturize the antenna as well. Therefore, an antenna having an ideal length and size should be built in. Is difficult, and it is necessary to use an antenna element that is short for the wavelength, or it is necessary to reduce the size of the antenna while securing an effective tuning wavelength as much as possible.

As described above, the input reactance is negative (-) when the antenna length (L) is short with respect to the antenna length (for example: L = λ / 4) tuned to the wavelength.
Then, it has a capacitive impedance (capacitance). Therefore, a positive (+) reactance opposite to the feeding point, that is, an inductive impedance (inductance) such as a coil may be provided as a load. Generally, when it is desired to shorten the antenna length, a loading coil may be used as shown in FIG. It should be noted that FIG. 3A shows a quarter-wave dipole antenna without a loading coil for comparison.

However, as shown in the current distribution shown in FIG. 1 or 2, when the load is placed near the feeding point where the current is largest, the loss is large and the efficiency of the antenna is lowered. . Therefore, the effective height of the antenna becomes shorter than the height of the antenna decreases.

On the contrary, when a capacitive impedance is loaded on the outer end of the antenna whose current distribution is "0",
As shown in the voltage distributions shown in FIGS. 1A to 1C, since the charge is being accumulated, even if the portion is replaced with a capacitor, the characteristics do not change much. In this way, if a load is provided at the outer end of the antenna, or if a concentrated capacitance is provided at the outer end of the antenna as shown in FIGS. Without doing so, the antenna length (L) can be reduced to ¼ wavelength or less and an antenna having an effective length similar to a half wavelength can be obtained. An embodiment of the antenna for portable wireless device of the present invention, to which the above-described antenna principle is applied, will be described below.

B. First Embodiment FIG. 5A is a front view showing the configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a first embodiment of the present invention is applied, and FIG. 5B is a first embodiment. It is a circuit diagram which shows the equivalent circuit of the antenna for portable wireless devices by an example. In the figure, wristwatch type wireless devices are roughly divided into clock functions,
Provided at one end of the band portion 2a for stopping the body portion 1 in which electronic parts such as wireless functions are stored, the band portions 2a and 2b for fixing the body portion 1 to the arm, and the band portions 2a and 2b. The buckle portion 3 is provided.

The above-mentioned main body portion 1 has a wireless circuit portion 6 and a conductive power supply terminal 7 as the components according to the present invention.
a and 7b are provided. The input and output ends of the wireless circuit unit 6 are connected to one ends of the power supply terminals 7a and 7b, respectively. The other ends of the power supply terminals 7a and 7b are electrically and physically fixed to one end of the antenna element 10a extending in the longitudinal direction inside the band portion 2a by a conductive screw 7c or the like. On the other hand, the other end of the power supply terminal 7b is connected to the band portion 2b.
Inside, the antenna element 10b extending in the longitudinal direction is electrically and physically fixed by a screw 7d.

The radio circuit section 6 supplies electric power to the antenna elements 10a and 10b, which will be described later, through the power supply terminals 7a and 7b, and at the same time extracts the received electric power received by the antenna elements 10a and 10b. Each of the antenna elements 10a and 10b is made of a plastic conductor such as a metal plate, a metal thin film, or an electric wire, and a part of the power supply terminals 7a and 7b side is formed into a zigzag pattern and a loading / loading pattern is formed.
By forming the coils 11a and 11b, a load of inductive impedance (inductance) is loaded. Since the power supply terminals 7a and 7b are provided between the main body 1 and the movable band portions 2a and 2b, they are made of a flexible base material or the like.

B-1. Modification of First Embodiment Further, in a modification of the first embodiment, FIG.
As shown in (b), the main body portion 1 is provided with a wireless circuit portion 6, loading coils 12a and 12b, and conductive power supply terminals 7a and 7b, which are components related to the present invention. There is. Loading coils 12a, 12b
Are the input / output terminals of the wireless circuit section 6 and the power supply terminals 7a and 7a, respectively.
It is connected between one end of b and carries a load of inductive impedance (inductance). The wireless circuit unit 6 includes antenna elements 13a, 13b via the loading coils 12a, 12b and power supply terminals 7a, 7b.
b while supplying power to the antenna elements 13a, 13b
The received power received at is taken out. Antenna element 13a,
Each of 13b is made of a plastic conductor such as a metal plate, a metal thin film, or an electric wire, and is different in that it does not have the above-mentioned loading coil portion.

In this way, in the first embodiment, the dipole antenna is built in the band portions 2a and 2b, and the inductance is loaded (loading coil) on the feeding terminals 7a and 7b side of the dipole antenna. For the wavelength of the radio wave of the tuning frequency of, without lowering the efficiency or gain,
The effective length of the antenna can be made equivalent to the actual size of the antenna, and the size can be reduced. It can also be used for wireless devices that use high-frequency radio waves in the ultra-high frequency band or higher, and it is not necessary to mount or unwind it at the time of use, thus improving usability. Furthermore, since the loop is not configured via the buckle part, the structure and manufacturing of the buckle part is simple and easy to manufacture.Because the thickness of the user's arm is not affected, the antenna length changes. Without this, the antenna characteristics and the sensitivity, performance, and stability of the wireless device can be improved.

C. Second Embodiment In a second embodiment according to the present invention, a dipole type antenna radiating element is also built in the band part, and a parasitic element without a feeding terminal is arranged in parallel with the antenna radiating element to provide no parasitic power. By making the element function as a reflector similar to the Yagi antenna, we have realized an antenna for mobile wireless devices.

FIG. 7A is a front view showing the structure of a wristwatch type wireless device to which the portable wireless device antenna according to the second embodiment of the present invention is applied, and FIG. 7B is the second embodiment. It is a circuit diagram which shows the equivalent circuit of the antenna for portable wireless devices by an example. The parts corresponding to those in FIG. 5 or 6 are designated by the same reference numerals and the description thereof will be omitted. In the figure, the input and output ends of the wireless circuit section 6 are connected to one ends of the power supply terminals 7a and 7b, respectively. The other end of the power supply terminal 7a has a band portion 2a.
Is electrically and physically fixed to one end of the antenna element 14a extending in the longitudinal direction. On the other hand, the other end of the power supply terminal 7b is electrically and physically fixed to one end of the antenna element 14b extending in the longitudinal direction inside the band portion 2b. The antenna elements 14a and 14b are
Each of them is made of a plastic conductor such as a metal plate, a metal thin film, or an electric wire, and extends straight in the longitudinal direction of the band portion to form a dipole antenna. Further, in the band portions 2a and 2b, parasitic elements 15a and 15b having no feeding terminals are arranged in parallel with the antenna elements 14a and 14b at intervals d. The parasitic elements 15a and 15b are short-circuited inside the main body 1 and function as a reflector similar to the Yagi antenna with respect to the antenna elements 14a and 14b.

C-1. Modification of Second Embodiment As a modification of the second embodiment, FIGS. 8A and 8B are used.
As shown in FIG. 2, the antenna elements 1 are attached to the band portions 2a and 2b.
6a, 16b and the parasitic elements 15a, 15b are separated by a distance d.
Spaced 1 apart. Antenna elements 16a and 16b
The outer end portion of is bent at a right angle toward the parasitic elements 15a and 15b, and is brought close to the distance d2 (d2> d1). As a result, a negative (-) reactance component,
That is, since the capacitive impedance (capacitance) is loaded, the effective length can be increased, and the actual size of the antenna can be shortened and miniaturized with respect to the tuning wavelength.

C-2. Modification of Second Embodiment As a modification of the second embodiment, FIGS. 9A and 9B are used.
As shown in FIG. 2, the antenna elements 1 are attached to the band portions 2a and 2b.
7a, 17b and the parasitic elements 15a, 15b are separated by a distance d.
Spaced 1 apart. Antenna elements 17a, 17b
Is bent toward the parasitic elements 15a and 15b at an angle θ from the middle thereof, and the outer end portion and the parasitic element 15 are bent.
The distances a and 15b are close to each other until a distance d2 (d2 <d1) is satisfied. As a result, as in the modification described above, a negative (-) reactance component, that is, a capacitive impedance (capacitance) is loaded, so that the effective length can be increased and the actual size of the antenna can be shortened with respect to the tuning wavelength. ,
Can be miniaturized.

D. Third Embodiment Next, FIG. 10A is a front view showing a configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a third embodiment of the present invention is applied, and FIG. It is a conceptual diagram which shows schematic structure of the antenna for portable radio | wireless apparatuses by 3rd Example. Note that the portions corresponding to those in FIG. In the figure, in the band portion 2a, a conductor 18 and a ground plate 19 made of a conductor, which sandwich a material of the band portion or a dielectric material such as Teflon, are arranged. The length a (≒ λ
/ (4√ε)) and has a width b on the side of the main body 1
At 0, it is connected to the ground plate 19. The conductor 18 and the ground plate 19 that sandwich the dielectric material act as an inverted F type quarter-wave strip antenna.

D-1. Modification of Third Embodiment Next, in a modification of the third embodiment, as shown in FIG.
As shown in FIG. 12B or FIG. 12A to FIG. 12C, in place of the above-described conductor 18, the outer end portion is brought close to the ground plate 19 side with a length c ′ so as to be connected to the ground plate 19. The conductor 21 whose distance is shortened so that d2 <d1 is built in the band portion 2a,
The capacitive impedance is equivalently loaded (top loading), and the effective antenna length is set to a'≤λ / (4√ε). The outer end portion of the conductor 21 on the main body 1 side is connected to the ground plate 1 by the short-circuit portion 22 penetrating the dielectric.
9 is connected. As a result, the actual size a ′ of the antenna can be shortened and the size can be reduced.

E. Fourth Embodiment Next, FIG. 13A is a front view showing a configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a fourth embodiment of the present invention is applied, and FIG. 13 is a conceptual diagram showing a schematic configuration of an antenna for portable radio equipment according to an embodiment, FIG.
(C) is a circuit diagram showing an equivalent circuit of the portable radio device antenna. Note that the portions corresponding to those in FIG. In the figure, the band portion 2a
Is the material of the band part or the dielectric 23 such as Teflon.
An antenna element 24 made of a conductive material and a ground plate 25 made of a conductive material are provided to sandwich the antenna element 2
Reference numeral 4 denotes a short-circuit portion 26 on the main body 1 side, which is connected to the ground plate 25. The antenna element 24 and the ground plate 25 that sandwich the dielectric 23 function as an inverted F type quarter-wave strip antenna. Further, a parasitic element 27 made of a conductor connected to the ground plate 25 is provided on the outer end side of the inverted F type quarter-wave strip antenna. This parasitic element 27 acts as a director. The antenna according to the fourth embodiment has an equivalent circuit as shown in FIG. In this case, since the parasitic element 27 has a capacitive impedance (capacitance) loaded between the antenna element 24 and the ground plate 25, the antenna element 24 can be shortened and downsized. Here, FIG. 14A is an equivalent circuit of an inverted F-type strip antenna having a parasitic element stub, and FIG. 14B is a conceptual diagram showing a bandwidth characteristic of the inverted F-type strip antenna. . In FIG. 14B, the dotted line is the bandwidth when there is no parasitic element, and the solid line is the bandwidth when there is a parasitic element. As shown in the figure, due to the effect of the waveguide by the parasitic element stub, the bandwidth can be widened and the characteristics can be improved.

E-1. Modification of Fourth Embodiment Further, in a modification of the fourth embodiment, as shown in FIG.
As shown in (b), instead of the parasitic element 27 described above, a part of the metal fitting of the metal buckle portion 28 is used as the parasitic element 29. The parasitic element 29 is short-circuited to the ground plate 25 by a conductive screw 28a for fixing the metal fitting of the buckle portion 28. In this case, the shortened antenna according to the modification of the fourth embodiment has an equivalent circuit as shown in FIG. Also in this case, since the parasitic element 29 becomes the capacitive impedance (capacitance) loaded between the antenna element 24 and the ground plate 25 as in the fourth embodiment, the antenna element 24 can be shortened. , Can be miniaturized.

F. Fifth Embodiment Next, FIG. 16A is a front view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a fifth embodiment of the present invention is applied, and FIG. It is sectional drawing of the antenna for portable radio | wireless apparatuses by 5th Example. Also, FIG.
7 (a) is a perspective view of an antenna for a mobile wireless device,
FIG. 17B is an equivalent circuit of the antenna for portable wireless device. Note that the portions corresponding to those in FIG. 16 (a), (b) and FIG.
As shown in (a) and (b), in the band portion 2a, a quarter wavelength short circuit in which the outer end portion of the antenna element 31 on the main body side is short-circuited to the ground plate 32 by a short-circuit connection portion (micro stub) 30. Type inverted F-type strip antenna is built in. Further, in order to shorten the actual size of the antenna element 31, a plurality of slit-like notches 31a, 31b, 31c having a length a are provided in the middle of the antenna element 31 at substantially equal intervals (interval b). Then, the reactance element and the resistance component are equivalently loaded in the antenna element 31. As a result, the effective antenna length becomes a ≦ λ / 4, and the antenna element 31 can be shortened and downsized.

G. Sixth Embodiment Next, FIG. 18A is a front view showing the configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a sixth embodiment of the present invention is applied, and FIG. It is sectional drawing of the antenna for portable radio | wireless apparatuses by 6th Example. In the figure, the band parts 2a and 2b are provided with antenna elements 40a and 40b made of a conductor and extending in the longitudinal direction of the band parts.
A plurality of slit-like notches (cutouts) of length a
1a, 41b, 41c, 41d, and 42a, 42
b, 42c, 42d, and 42e are provided at substantially equal intervals (interval b), and reactance elements and resistance components are equivalently loaded in the antenna elements 40a and 40b. The outer end of the antenna element 40a on the side of the band portion 2a has a metallic buckle portion 2
8 is extended to the bottom and the buckle portion 28 is short-circuited to the buckle portion 28 by a conductive screw 45 for fixing the buckle portion 28 to the band portion 2a. When the buckle portion 28 is engaged with the buckle stopper piece 46 provided on the side of the band portion 2b, the buckle portion 28 has an antenna element 40a and an antenna element 40b.
A loop connection portion 47 formed of a leaf spring for electrically connecting and is provided. Further, an L tap is provided in the middle of the antenna element 40a, and the input / output end of the radio circuit unit 6 is connected to the outer end of the antenna element 40a and the outer end of the L tap. One input / output terminal of the wireless circuit unit 6 is connected to the outer end of the antenna element 40b via a variable-capacitance tuning capacitor 48.

FIG. 19 (a) is a perspective view of the antenna for portable radio equipment when the buckle portion is engaged, and FIG.
9 (b) is an equivalent circuit of the antenna for portable radio equipment at that time. 20 (a) is a perspective view of the portable wireless device antenna when the buckle portion is removed, and FIG.
Is an equivalent circuit of the antenna for portable radio equipment at that time. The antenna elements 40a and 40b are the buckle portion 2
When 8 is engaged with the buckle stopper piece 46, as shown in FIG.
As shown in (a) and (b), it acts as an L-tap type loop antenna, and when the buckle portion 28 is removed,
As shown in FIGS. 20 (a) and 20 (b), it operates as an inverted F type quarter-wave antenna.

As described above, in the sixth embodiment, when it is worn on the arm and the band portions 2a and 2b are looped, it functions as an L-tap type loop antenna, so that it functions as an antenna for a magnetic field component near the human body, On the other hand, when the band parts 2a and 2b are opened by removing them from the arm,
Since it functions as an inverted F-type quarter-wave antenna, it functions as an antenna for electric field components distant from the human body. As a result, the gain and directivity can be improved as a whole in response to changes in usage conditions and environmental changes.

H. Seventh Embodiment In the above-described first to sixth embodiments, the shortened band antenna in which reactances such as inductance and capacitance are loaded by using passive elements is used. However, in the seventh embodiment, instead of passive elements, Then, a shortened band antenna is constructed by loading active elements such as diodes and transistors. An antenna that is smaller than the wavelength has a large reactance component but a small resistance component, so that it is possible to improve the efficiency of the antenna by loading passive elements. However, the gain of a small dipole antenna of about 1/8 to 1/10 wavelength is about 8 to 10 dB lower than that of a standard 1/2 wavelength dipole. This decrease in gain is
It is largely due to loss resistance due to the loaded reactance element.

FIG. 21 is a front view showing the structure of a wrist watch type wireless device to which the portable wireless device antenna according to the seventh embodiment of the present invention is applied. In addition, FIG.
FIG. 22B is a perspective view of the portable wireless device antenna according to the seventh embodiment, and FIG. 22B is a circuit diagram showing an equivalent circuit of the portable wireless device antenna. In the seventh embodiment, as shown in FIGS. 21 and 22 (a) and (b), a top plate (three-dimensional antenna element) 50 made of a conductor, an inverted F antenna element 51 made of a conductor, and a short circuit. Connection part (stub) 5
Inverse F connected to the inverse F antenna element 51 by means of 3
The inverted F-type antenna including the ground plate 52 is laminated to form two antennas in the band portion 2a. A line 50a for feeding is provided on the main body side of the upper plate 50, and the outer end of the line 50a is bent into a layer of the inverted F antenna element 51. The base of the transistor 54 is connected to the outer end of the line 50a.
The collector of the transistor 54 is connected to the inverted F antenna element 51, and the emitter is connected to the power supply terminal 55a provided in the layer of the inverted F antenna element 51. FIG. 22B is a conceptual diagram showing the connection of the transistor 54. Power is supplied from the wireless circuit unit 6 to the reverse F ground plate 5
2 through the power supply terminal 55b and the power supply terminal 55a to which the emitter of the transistor 54 is connected.

As described above, in the seventh embodiment, by inserting an active element such as a transistor, it is possible to add a function of amplifying and compensating for a decrease in the signal due to the loss resistance during the loading reactance. As a result, the loss can be reduced, the actual size of the antenna can be shortened, and the size can be reduced. Also,
By electronically controlling the input of active elements such as transistors, it is possible to control or switch the antenna characteristics from the circuit side. For example, by providing multiple antenna elements, the frequency, polarization direction, and use It can also be used for applications such as diversity antenna control for switching or combining antenna elements according to the environment, or switching antenna elements or controlling characteristics according to functions such as transmission and reception.

H-1. Modification of Seventh Embodiment In a modification of the seventh embodiment, as shown in FIGS. 23 and 24A to 24C, the inverted F antenna element 51 and the short-circuit connecting portion (stub) described above are provided. In addition to the inverted F type antenna in which the inverted F ground plate 52 connected to the inverted F antenna element 51 by 53) is laminated, a loop element 61 made of a conductor and having a slit 60 is arranged in parallel. The base and collector of the transistor 62 are connected to the outer end of the loop element 61 forming the slit 60.
The collector of the transistor 62 is connected to the inverted F antenna element 51, and the emitter thereof is connected to the power supply terminal 63a provided in the layer of the inverted F antenna element 51. FIG. 24B is a conceptual diagram showing connection of transistors. Power is supplied from the wireless circuit unit 6 to the power supply terminal 63b connected to the reverse F ground plate 52 and the transistor 62.
Is performed via the power supply terminal 63a to which the emitter of is connected.

In this case, by inserting an active element such as a transistor, the signals of the loop element (antenna 1) 61 and the inverted F antenna element (antenna 2) 51 are amplified and compensated as shown in FIG. 24 (c). Function can be added. As a result, as described above, the loss can be reduced, so that the actual size of the antenna can be shortened and the size can be reduced. By electronically controlling the input of an active element such as a transistor, the characteristics of the antenna can be controlled or switched from the circuit side.

I. Application Example Next, a portable wireless device to which the shortened antenna according to the above-described embodiment of the present invention is applied will be described. I-1. Wristwatch-type FM stereo radio and FM teletext receiver FIG. 25 is a block diagram showing the configuration of a wristwatch-type FM stereo radio and an FM teletext receiver using the above-described shortened antenna as a receiving antenna. . In the figure, the radio signal received by the shortened antenna 140 is
It is supplied to the FM front end 142 via the bandpass filter 141. Under the control of the control circuit 155, the FM front end 142 generates an intermediate frequency by a mixing circuit (MIXER) that mixes with a signal of a local oscillator by a PLL or the like, detects a signal of a desired channel, and outputs the intermediate frequency signal as an intermediate frequency signal. The signal is supplied to the IF amplifier 144 via the transformer 143. The IF amplifier 144 is
The intermediate frequency signal is amplified and the band pass filter 145, F
The FM detection signal is supplied to the stereo demodulator 147 and the bandpass filter 149 via the M detection circuit 146. The stereo amplifier 147 demodulates the L (left) audio signal and the R (right) audio signal of the stereo audio signal from the FM detection signal and supplies them to the audio amplifier 148. The L audio signal and the R audio signal are respectively amplified by the audio amplifier 148 and sounded by the speakers SP (L) and SP (R).

On the other hand, the FM from the FM detection circuit 146
The detection signal (FM mixed signal) is passed through the bandpass filter 14
The sub-carrier multiplexed signal component is extracted via 9 and M
It is supplied to the SK demodulator 150. The MSK demodulator 150 demodulates the subcarrier multiplexed signal, extracts the character multiplexed signal, and supplies it to the decoder 152 and the clock regenerator 153 via the LPF 151. The decoder 152 decodes the code data of the character information from the demodulated signal and supplies it to the control circuit 155. On the other hand, the clock regenerator 153
Synchronous circuit 1 recovers the basic clock from the demodulated signal.
Supply to 54. The synchronization circuit 154 generates a synchronization clock that is in synchronization with the basic clock and supplies it to the control circuit 155.

The control circuit 155 selects the operation channel from the input unit 156, operates the radio receiver, operates the clock function, and the like according to the instruction, and selects the FM channel.
It supplies the data to the front end 142 and controls the memory 157, the error corrector 158, and the display controller 160. The received character information described above is stored in the memory 157 under the control of the control circuit 155. At this time, the error corrector 158 corrects the contents of the memory 157. C. G. FIG. (Character Generator) 159
Generates character data according to the character information stored in the memory 157 and supplies it to the display controller 160.
The display controller 160 follows the control of the control circuit 155.
The LCD 161 is controlled to display the character data.

I-2. 26. Wristwatch-type FM wireless microphone or FM character code transmitter Next, FIG. 26 is a block diagram showing a configuration of a wristwatch-type FM wireless microphone and an FM character code transmitter using the above-described shortened antenna as a transmitting antenna. is there. In the figure, the audio signal collected by the microphone 170 is amplified by the low-frequency amplifier 171, and then the signal selection unit 172.
Supplied to On the other hand, the character information input from the input unit 173 is stored in the memory 175 via the control unit 174. The character information stored in the memory 175 is stored in the control unit 1
Under the control of 74, the data is transferred to the display data register 176. C. G. FIG. (Character generator) 177
Generates character data according to the character information stored in the memory 175 and supplies it to the display controller 178.
Display on CD179.

On the other hand, the character information stored in the memory 175, that is, the character information input from the input unit 173 is converted into serial data by the PS (parallel-serial) conversion unit 180, and then the FSK modulation unit. 181
And is supplied to the signal selection unit 172. The signal selection unit 172 supplies the above-described voice signal or modulated character information to the FM modulator 182 according to a predetermined format under the control of the control unit 174. The voice signal or character information is modulated by the FM modulator 182 at the frequency generated by the oscillator 183, and the frequency multiplier 18 is used.
After being multiplied by 4, after being amplified by the power amplifier 185,
It is radiated from the shortened antenna 186.

I-3. Wrist Watch Type Mobile Phone Next, FIG. 27 is a block diagram showing a configuration of a wrist watch type mobile phone using the above-described shortened antenna as a transmitting / receiving antenna. In the figure, a reception signal received by the shortened antenna 190 as a transmission / reception antenna is transmitted through the RF switch 191 which distributes transmission / reception to R
The IF (intermediate frequency) in the vicinity of the 1.9 GHz band to the 10 MHz band is supplied to the F section (frequency conversion section) 192 and mixed with the local oscillation signal of a predetermined frequency output from the PLL synthesizer (not shown) on the receiving side. The signal is frequency-converted and supplied to the demodulator 193a of the modem unit 193. Next, the demodulator 193a of the modem unit 193 demodulates the IF signal from the RF unit 192, separates it into IQ data, and outputs it as a data string to the TDMA channel link control circuit (or channel decoder / encoder) 194. Send out. Next, the receiving section of the TDMA channel link control circuit 194 extracts data for one slot from the received data supplied from the modem section 193 at a predetermined timing, and extracts a unique word (synchronization signal) from this data. To generate a frame synchronization signal, and descramble the control data section and the audio data section. Then, the control data is sent to the control circuit 196, and the voice data is sent to the voice codec unit 195. Next, the voice codec unit 195 described above converts the ADPCM voice signal (4 bits × 8 KHz = 32 Kbps) supplied from the TDMA channel link control circuit 194 into the PCM voice signal (8 bits × 8 KHz) by the AD-PCM code decoder 195 a. = 64 Kbps) to expand the audio signal, and the audio interface 195b converts the audio signal into an analog audio signal and causes the speaker SP to generate sound.

On the other hand, the voice signal input from the microphone MIC is converted into a digital signal by the audio interface 195b, and then the AD-PCM code decoder 1
In 95a, the ADPCM voice signal is encoded and compressed to be sent to the TDMA channel link control circuit 194. Next, the TDMA channel link control circuit 1
The transmitting unit 94 adds control data and the like to the voice data supplied from the voice codec unit 195, adds a unique word and the like after adding scramble and the like, creates transmission data for one slot, and sets the predetermined data. The modem section 19 is inserted at a timing into a predetermined slot in the frame.
Send to 3. Next, the modulation unit 193b of the modem 193 creates IQ data from the data supplied from the TDMA channel link control circuit 194, and the π / 4 shift Q is generated.
The PSK is modulated and sent to the RF unit 192. next,
The transmission unit of the RF unit 192 is the modulation unit 19 of the modem unit 193.
The modulated wave of π / 4 shift QPSK supplied from 3b is
By mixing with a local oscillation signal of a predetermined frequency output from a PLL synthesizer (not shown), 1.9 GHz
The frequency is converted into a band and radiated from the shortened antenna 190 via the RF switch 191.

The control circuit 196 controls the RF switch 191, the TDMA channel link control circuit 194, the voice codec unit 195, etc. described above, and also sends the display data to the display control unit 197 for display on the LCD 198. The ID memory 199 stores data for identifying the user of the mobile phone. The input unit 200 is composed of a numeric keypad for inputting the telephone number of the other party, a switch for on-hook / off-hook, a volume switch for changing the voice output, and the like. The control circuit 196 indicates the state of these keys and switches. Supply.

As described above, the shortened antenna of this embodiment is a wristwatch type FM stereo radio and FM teletext receiver, a wristwatch type FM wireless microphone and an F type.
It can be used for an M character code transmitter, a wristwatch-type mobile phone, or the like, and can be fully utilized as long as it is a wristwatch-type transceiver.

[0055]

According to the present invention, a feeding antenna element made of a conductor having plasticity is provided in the band portion, and the feeding end portion of the feeding antenna element is loaded with inductive impedance or its outer end portion. Since the capacitive impedance is loaded on the antenna and used as a transmitting / receiving antenna, the following effects can be obtained. (1) The effective length of the antenna can be made equivalent to the actual size of the antenna without lowering the efficiency or gain with respect to the wavelength of the radio wave of the desired tuning frequency, and the size of the antenna can be reduced. it can. (2) Since it does not use a bar antenna, it can be used for wireless devices that use high-frequency radio waves in the ultra-high frequency band or higher. (3) Also, unlike the string type antenna that doubles as an earphone, it does not need to be attached or unwound at the time of use, improving usability. (4) Further, since the loop is not formed via the buckle portion, the structure and manufacturing of the buckle portion are simplified, and the buckle portion can be easily manufactured. (5) Also, since it is not affected by the thickness of the user's arm,
The antenna length does not change, and the antenna characteristics and the sensitivity, performance, and stability of the wireless device can be improved. (6) When attached, it can act as an L-tap type loop antenna, while when not attached, it can act as an inverted F type 1/4 wavelength antenna.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a current distribution and a voltage distribution of a half-wavelength dipole antenna, a quarter-wavelength monopole antenna, etc. for explaining the principle of an antenna for portable radio equipment according to the present invention.

FIG. 2 is a conceptual diagram showing changes in input impedance and reactance with respect to the antenna length of a linear antenna.

FIG. 3 is a conceptual diagram showing a difference in antenna length depending on the presence or absence of a loading coil.

FIG. 4 shows that the antenna length is shortened by providing a concentrated capacitance at the outer end of the antenna.
It is a conceptual diagram which shows the example of a 4-wavelength dipole antenna.

FIG. 5 is a front view showing the configuration of a wristwatch-type wireless device to which the antenna for portable wireless device according to the first embodiment of the present invention is applied;
FIG. 3 is a circuit diagram showing an equivalent circuit of an antenna for portable radio equipment.

6A and 6B are a front view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a modified example of the first embodiment is applied, and a circuit diagram showing an equivalent circuit of the antenna for a portable wireless device.

FIG. 7 is a front view showing the configuration of a wristwatch-type wireless device to which the portable wireless device antenna according to the second embodiment of the present invention is applied;
FIG. 3 is a circuit diagram showing an equivalent circuit of an antenna for portable radio equipment.

FIG. 8 is a front view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a modification of the second embodiment is applied, and a circuit diagram showing an equivalent circuit of the antenna for the portable wireless device.

FIG. 9 is a front view showing a configuration of a wristwatch-type wireless device to which an antenna for a portable wireless device according to a modified example of the second embodiment and a circuit diagram showing an equivalent circuit of the antenna for a portable wireless device.

FIG. 10 is a front view showing a configuration of a wristwatch-type wireless device to which an antenna for a portable wireless device according to a third embodiment of the present invention is applied, and a conceptual diagram showing a schematic configuration of the antenna for a portable wireless device.

FIG. 11 is a front view and a cross-sectional view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a modified example of the third embodiment is applied.

FIG. 12 is a perspective view of a portable wireless device antenna according to a modification of the third embodiment, a schematic configuration diagram of the portable wireless device antenna, and a circuit diagram showing an equivalent circuit of the portable wireless device antenna.

FIG. 13 is a front view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a fourth embodiment of the present invention is applied, a conceptual diagram showing a schematic configuration of an antenna for a portable wireless device,
FIG. 3 is a circuit diagram showing an equivalent circuit of an antenna for portable radio equipment.

FIG. 14 is a conceptual diagram showing an equivalent circuit of an inverted F-type antenna having a parasitic element stub and a bandwidth characteristic of the inverted F-type antenna.

FIG. 15 is a front view showing a configuration of a wristwatch type wireless device to which an antenna for a portable wireless device according to a modification of the fourth embodiment is applied, a conceptual diagram showing a schematic configuration of the antenna for a portable wireless device,
FIG. 3 is a circuit diagram showing an equivalent circuit of an antenna for portable radio equipment.

FIG. 16 is a front view showing a configuration of a wristwatch type wireless device to which an antenna for portable wireless device according to a fifth embodiment of the present invention is applied, and a sectional view of the antenna for portable wireless device according to the fifth embodiment.

FIG. 17 is a perspective view of an antenna for portable radio equipment and an equivalent circuit of the antenna for portable radio equipment according to the fifth embodiment.

FIG. 18 is a front view and a cross-sectional view showing a configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a sixth embodiment of the present invention is applied.

FIG. 19 is a perspective view showing an antenna for portable radio equipment when a buckle portion is engaged and a circuit diagram showing an equivalent circuit at that time in the sixth embodiment.

20A and 20B are a front view showing an antenna for portable radio equipment when a buckle portion is removed and a circuit diagram showing an equivalent circuit at that time in the sixth embodiment.

FIG. 21 is a front view showing a configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a seventh embodiment of the present invention is applied.

FIG. 22 is a perspective view of an antenna for portable radio equipment according to the seventh embodiment and a circuit diagram showing an equivalent circuit thereof.

FIG. 23 is a front view showing the configuration of a wrist watch type wireless device to which an antenna for a portable wireless device according to a modified example of the seventh embodiment is applied.

FIG. 24 is a perspective view of an antenna for a portable wireless device according to a modification of the seventh embodiment, an equivalent circuit diagram thereof, and a block diagram showing its function.

FIG. 25 is a block diagram showing a configuration of a wristwatch type FM stereo radio and an FM teletext broadcast receiver using a shortened antenna as a receiving antenna as an application example of the present invention.

FIG. 26 is a block diagram showing a configuration of a wristwatch type FM wireless microphone and an FM character code transmitter using a shortened antenna as a transmitting antenna as an application example of the present invention.

FIG. 27 is a block diagram showing a configuration of a wristwatch type mobile phone using a shortened antenna as a transmitting / receiving antenna as an application example of the present invention.

[Explanation of symbols]

1 main body part 2a, 2b band part 3 buckle part 6 wireless circuit part 7a, 7b feeding terminal 10a, 10b antenna element (feeding antenna element) 7c, 7d screw 11a, 11b loading coil (inductive impedance) 12a, 12b loading Coil (inductive impedance) 13a, 13b Antenna element (feed antenna element) 14a, 14b Antenna element (feed antenna element) 15a, 15b Parasitic element (parasitic antenna element) 16a, 16b Antenna element (feed antenna element) 17a, 17b Antenna element (feed antenna element) 18 Conductor 19 Ground plate 21 Conductor 22 Short-circuit part 23 Dielectric 24 Antenna element (feed antenna element) 25 Ground plate 26 Short-circuit part 27 Parasitic element (parasitic antenna element) 28 Buckle part 29 Parasitic element (parasitic antenna element) 30 Short-circuit connection part 31 Antenna element (feeding antenna element) 32 Ground plate 31a, 31b, 31c Cut (notch) 40a, 40b Antenna element 41a-41d, 42a-42e Cut (notch) ) 45 conductive screw 46 buckle stopper 47 loop connection part 48 tuning capacitor 50 top plate 51 reverse F antenna element 52 reverse F ground plate 53 short circuit connection part (stub) 54 transistors 55a, 55b power supply terminal 60 slit 61 loop element 62 transistor (Active element) 63a, 63b Feeding terminals 140, 186, 190 Shortened antenna

Claims (6)

[Claims] 1. An antenna for a mobile wireless device used as an antenna of a mobile wireless device worn by a user by a band portion provided on a main body, wherein the band portion is a conductor having plasticity, A feeding antenna element that is fed from the central point is provided so that the distribution of the current flowing in the longitudinal direction of the body is symmetrical with respect to the central point, and an inductive impedance is loaded at the feeding end of the feeding antenna element. A featured antenna for mobile wireless devices. 2. An antenna for a mobile wireless device used as an antenna of a mobile wireless device worn by a user by a band portion provided on a main body, wherein the band portion is a conductor having plasticity, A feeding antenna element that is fed from the center point is provided so that the distribution of the current flowing in the longitudinal direction of the body is symmetrical with respect to the center point, and a capacitive impedance is loaded on the outer end of the feeding antenna element. A featured antenna for mobile wireless devices. 3. An antenna for a mobile wireless device used as an antenna of a mobile wireless device worn by a user by means of a band portion provided on the main body, wherein the conductor is a plastic conductor, and the conductor is arranged in a longitudinal direction of the conductor. The power is fed from the center point so that the distribution of the flowing current is symmetrical with respect to the center point, and the power feeding antenna element provided in the band portion and the power feeding antenna element are arranged side by side at a predetermined interval and are not fed. An antenna element is provided, and a capacitive impedance is loaded on the outer end portion of the feeding antenna element by bringing the outer end portion of the feeding antenna element close to the parasitic antenna element side. For antenna. 4. An antenna for a mobile wireless device, which is used as an antenna of a mobile wireless device worn by a user by a band portion provided on a main body, wherein the band portion is made of a plastic conductor, An inverted F-type antenna, which is composed of a feeding antenna element plate and a grounding plate, sandwiching the body from both front and back sides of the band part, and in which the outer ends of the feeding antenna element plate and the grounding plate are electrically short-circuited, is provided. An antenna for portable radio equipment, wherein an outer end portion of the feeding antenna element plate is bent toward the ground plate side and brought close to each other, and a capacitive impedance is loaded on the outer end portion of the feeding antenna element plate. 5. An antenna for a mobile wireless device, which is used as an antenna of a mobile wireless device worn by a user by a band portion provided on a main body, wherein the band portion is a conductor having plasticity, An inverted F-type antenna, which is composed of a feeding antenna element plate and a grounding plate, sandwiching the body from both front and back sides of the band part, and in which the outer ends of the feeding antenna element plate and the grounding plate are electrically short-circuited, is provided. In the middle of the feeding antenna element plate, by providing a plurality of slit-like cuts of a predetermined length at equal intervals,
An antenna for portable radio equipment, wherein a reactance element and a resistance component are equivalently loaded on the feeding antenna element plate. 6. An antenna for a mobile wireless device used as an antenna of a mobile wireless device worn by a user by a band portion provided on the main body, wherein the band conductive portion is formed of a plastic conductor. A loop element, a tap terminal is provided midway on the outer end side of the loop element, and one outer end of the loop element and the tap terminal are used as power supply terminals, while one outer end and the other end of the loop element are provided. By connecting a variable capacitance element to the outer end of the loop element, and by providing a plurality of slit-shaped cuts of a predetermined length at equal intervals in the middle of the loop element, a reactance element and a resistance component are provided in the loop element. Equivalently loaded, it acts as an L-tap type loop antenna when the band part is in a loop state, while it is an inverted F type antenna when the band part is in an open state. Antenna for a portable radio device, characterized in that acting as a container.