JPS62209904A - Antenna for small-sized radio equipment - Google Patents

Abstract

PURPOSE:To secure the satisfactory communicating sensitivity even when the using condition of the small-sized radio equipment is changed by being equipped with at least two pairs of the one side short-circuiting microstrip type antenna having a mutually different exciting direction. CONSTITUTION:The first and second antennas 10 and 20 having a mutually different exciting direction are connected to a circuit board 40 of a radio equipment. The first antenna 10 is a one side short-circuiting microstrip antenna of a two-layer structure and the second antenna 20 is a one side short-circuiting microstrip antenna of a three-layer structure. For example, when the first antenna 10 is resonated to the electromagnetic wave of a transmitting side opponent station 103 and the electric power source is supplied to the first amplifier 50, the output signal from a wireless part 53 comes to be the low noise. This is decided by a data processing part 54, and an electric power source supplying circuit 52 is controlled so as to execute the subsequent electric power source supply to the first amplifier 50. Thus, the antenna used for receiving comes to be the first antenna 10 only, and the second antenna 20 is separated from the circuit system of the radio equipment.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an antenna device for small radio equipment.

(Prior Art) Due to its functionality, small radio equipment is not always used in a fixed position. For example, as shown in FIG.
It may be used in f) position 1, or it may be used in horizontal position 102.

Conventional antennas for small radios have only a single excitation direction, so it is most frequently used. It was designed to be implemented as such.

(Problems to be Solved by the Invention) However, in order to obtain good communication sensitivity under any usage conditions, it is necessary that the excitation direction of the antenna always coincides with the excitation direction of the communication partner antenna.

For example, the excitation direction 101 in the vertical position 101 shown in FIG.
a and the excitation direction 102a in the horizontal position 102 must each coincide with the excitation direction 103a of the communication partner antenna 103.

Therefore, the conventional small radio antenna designed as described above has a problem in that communication sensitivity is significantly degraded under usage conditions that were not taken into consideration in the design.

The present invention has been made to solve the above-mentioned problems, and is a small wireless device that can ensure good communication sensitivity even if the usage status of the small wireless device to be mounted changes. The purpose is to provide an antenna device for L aircraft.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides at least two sets of short-circuited micro-nutrip type antennas having mutually different excitation directions, and each of these antennas is integrated into a circuit system of a small radio device. The configuration also includes a connecting means for connecting.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the overall configuration of an antenna device for a small radio device according to this embodiment. Note that in this drawing and the drawings to be described later, xs y *2 indicates a coordinate system.

The antenna device for a small radio device of this embodiment mainly consists of first and second antennas 10° 20 having different excitation directions, means for connecting each of these antennas to the circuit board 40 of the radio device, and It is equipped with an automatic antenna switching circuit that automatically switches the antennas 10 and 20.

The means for connecting each antenna 10.20 to the circuit board 40 of the radio device consists of a male connector 41 provided on both sides of the circuit board 40 and a female connector 42.43 provided on each antenna 10.20. ing. These connectors 41
, 42 and 43 are specifically applied to pin sockets. With these connectors 41, 42, 43, each antenna 10, 20 can be easily mounted and attached during maintenance with one touch, improving work efficiency.

The first antenna 10 is a two-layer structure short-circuited microstrip antenna, and specifically has a straight structure as shown in FIG. Note that (a) in the same figure is a perspective view of the first antenna, and (6) in the same figure is a configuration diagram showing the magnetic current distribution of the antenna.

In the drawings, reference numeral 12 denotes a block-shaped dielectric material having external dimensions of length ai, width b1, and height t. An antenna element 13 made of a radiation conductor plate having a length Ll and a width W is attached to the top surface of the dielectric 12 in the drawing, and a short-circuit root (with a width W1 and a height t) is attached to the right side surface in the drawing. Connection conductor plate) 1
4 is attached, and a base plate 15 is attached over the entire bottom surface as shown. These antenna elements 13, short introduction plate 14,
When viewed from the Y direction, the base plate 15 has a U-shape with a long base, as shown in FIG. 2(b).

Here, the length of the antenna element 13 is determined so that it resonates at the frequency used. Example a1>Ll)
There is a b 1 O relationship. t and Wl are determined as appropriate parameters according to the desired band. This t, W,
It is desirable to make it as large as the antenna space allows.

The first antenna 10 having such a configuration has a power feeding point at a point W1/2 from the edge of the antenna element 13 in the IJ force direction, and a feeding bin 16 is provided at this point to feed power.
It is excited in the length direction (direction of arrow 10a in the figure). As shown in Figure 2, a magnetic current 10b is generated on the open end surface (left side in the figure), and the main radiation is carried out from this surface.The impedance can be changed by adjusting the position of the feeding point. be able to.

The second antenna 20 is a three-layer short-circuited microstrip antenna, and is specifically constructed as shown in FIG. Figure (a) is a perspective view of the second antenna, figure (b) is a perspective view of the state shown in figure (a) turned upside down, and figure II (C) is a perspective view of the electric field and magnetic current distribution. FIG.

In FIG. 3(a), a first antenna element (radiation conductor plate) 22° 23 is provided on the upper surface of a block-shaped dielectric 21, and a ground plate 2 is provided on the entire lower surface (see FIG. 3(b)).
4 are provided, and a second antenna element (radiating core body) 25.degree. 26 is provided at each intermediate position. Also,
The first antenna element 22.23 and the ground plane 24 are connected to the dielectric 2
First short circuit & (connecting conductor) 27°2 at one end of 1, respectively
8, and the second antenna elements 25 and 26 and the ground plate 2
4 are connected at the other end of the dielectric 21 by second short circuit plates (connection bodies) 29 and 30, respectively. In this way, the first antenna part 31 and the second antenna part 3 have a three-layer structure.
2 are installed on the same board. Note that the dimensions of the dielectric body 21 are the same as those of the first antenna 10: length aI, width bIs, and height t.

Here, the first antenna section 31 and the second antenna section 32
Each resonant frequency is set differently.

That is, the length L3 of one first antenna element 22 and the length L4 of the other first antenna element 23 are set to different dimensions, and the second antenna as a whole is adjusted to have two resonances. This makes it possible to make the band as wide as or even wider than that of the first antenna 10.

Also, the width W of the first antenna elements 22 and 23.

W4 is set so that the opening areas of each open end surface (surface corresponding to the upper left in FIG. 3(C)) and each side portion of the first antenna section 31 and the second antenna section 32 are approximately equal. By adjusting in this way, it is possible to secure an antenna gain equivalent to that of the first antenna 10.

In the second antenna 20 described above, when power is supplied to the power supply bins 33 and 34, a magnetic current 20a is generated at the open end face as shown in FIG. 3(C), and main radiation is performed from the end face. The excitation direction is the direction shown by the arrow 20b in FIG. 3(a) (width direction of the dielectric 21).

Furthermore, since the second antenna 20 consists of two sets of antenna parts, a first antenna part 31 and a second antenna part 32,
It is necessary to match these antenna parts.

By the way, the magnetic current 20a shown in FIG. 3(C) does not change unless the distribution state of the electric field 20C generated within each antenna section changes. Therefore, each antenna section 31
The matching between .degree. and 32.degree. can be performed by paying attention to the distribution state of the electric field of 20.degree. In other words, the part A shown in the figure has an electric field of 2
0C is low, and even if there is some change in this part, it will not have a large effect on the electric field distribution of the entire antenna. Therefore, paying attention to this point, a matching circuit is provided in the portion A shown in the figure. As a matching circuit, a strip line 35 is used, as shown in FIG. 3(b), and is provided on the base plate 24.

Furthermore, a matching element 36 such as a chip capacitor is attached as necessary.

FIG. 5 is a diagram schematically showing the directivity of each antenna 10.20 when the antennas 10.20 are placed in the positional relationship shown in FIG. 1.

As shown in FIG. 5A, when a radio wave in the excitation direction 1 (Ja) is sent from the transmitting partner station, the first antenna 10 resonates with this radio wave and sends it to the radio circuit. However, it does not resonate with the electric lamp in the excitation direction 20b and does not play the role of an antenna.

On the other hand, as shown in FIG.
When a radio wave in the excitation direction 20h is sent from the sending partner station, it can resonate with this radio wave and send it to the radio circuit, but it does not resonate with the radio wave in the excitation direction a.

In addition, each antenna 10.20 exhibits a directivity F that is almost symmetrical with respect to the x-y plane. Therefore, as shown in FIG. The reception sensitivity will not deteriorate even if the radio is installed in the same position, or even if the radio is turned upside down. The reason why each antenna 10.20 exhibits substantially symmetrical directivity in this way is that the ground planes 12, 24 are small.

By the way, the second and mth antennas 10 and 20 exhibit good sensitivity to radio waves in the excitation direction that resonate, respectively, but it is unclear how they act on radio waves in the excitation direction that do not resonate.

This is related to impedance.

If impedances between the radio circuit and each antenna or between the antennas are not matched, reception sensitivity may be adversely affected. Therefore, matching means (for impedance matching) that is the same as the matching means described for the second antenna 20 is provided in the first antenna 10, and these matching means can match the impedances between the respective components. Desirable...

Next, in the antenna comparison value for the small radio device of this example, the first and second antennas (10.20 A rolling circuit is provided, and its circuit configuration will be explained below.

FIG. 4 is a block diagram showing the automatic antenna switching (b) path.

In the drawing, 50 is a first amplifier connected to the first antenna 10, and 51 is a second amplifier connected to the second antenna 20. Power is alternately supplied to each of these amplifiers 50 and 51 by a power supply circuit 52. When power is supplied to the first amplifier 50, the first antenna 1
When a gain matching the gain of 0 and the gain of the first amplifier 50 is applied to the radio section 53 and power is supplied to the second amplifier 51, the gain of the second antenna 20 and the gain of the second amplifier 5
A gain matching the gain of 1 is obtained in the radio section 53. Here, if the gains of each amplifier 50.51 are the same, the gain input to the radio section 53 will be % of the gain of each antenna 10.20. That is, the difference between the gains input to the radio section 53 is the gain difference between the antennas 10 and 20, and this gain difference is reflected in the amount of noise in the signal output from the radio section 53.

The output signal from the wireless section 53 is sent to a data processing section 54 including a noise detection circuit, and compared there. and,
The data processing unit 54 sends a control signal to the power supply circuit 52 according to the noise level to control selection of the amplifier to which power is to be supplied.

For example, when the first antenna 10 resonates with the radio waves of the transmitting partner station 103, the output signal from the wireless section 53 has low noise when power is supplied to the first amplifier 50. The data processing unit 54 determines this and controls the power supply circuit 52 to supply power to the first amplifier 50 thereafter. As a result, the antenna used for reception is the first antenna 1.
0 only, and the second antenna 20 is in a state separated from the circuit system of the radio device. When the second antenna 20 resonates with the radio waves of the transmitting partner station 103, power is supplied to the second amplifier 51 in the same manner as described above, and only the second antenna 20 is used for reception.

By switching each antenna 10.20 and connecting it to the radio circuit system as described above, each antenna 10.20
without considering impedance matching between
Good sensitivity is always obtained.

(Effects of the Invention) As explained above, the present invention has a configuration including at least two sets of short-circuited microstrip antennas with different excitation directions, so that good communication sensitivity can be achieved even when the usage conditions of the small radio device change. It is effective in ensuring that

[Brief explanation of drawings]

1 to 5 are diagrams for explaining one embodiment of the present invention, in which FIG. 1 is a perspective view showing the overall configuration of an antenna device for a small radio, and FIG. 2(a) is a diagram of a first antenna. A perspective view, FIG. 2(b) is a configuration diagram showing the torsional current distribution of the antenna, and FIG.
a) is a perspective view of the second antenna, and FIG. 3(b) is a perspective view of the second antenna.
3 (C) is a configuration diagram showing the electric field and magnetic current distribution of the antenna, FIG. 4 is a block diagram showing the antenna automatic switching circuit, and FIG. 5 ( a
). (b) is a diagram showing an outline of the directivity of each antenna, and FIG. 6 is a diagram showing an example of a usage state of the small radio device. 10... First antenna 12... Dielectric material 13...
Antenna element 14... Shorting plate 15... Ground plate
16...Power supply pin 20...Second antenna 21
...Dielectric material 22.23--First antenna element 24--Ground plate 25.26--Second antenna element 27.28--First shorting plate 29.30--Second shorting plate 31...First antenna section 32...Second antenna section 33.34...Power supply bottle 35...Strip line 36...Matching element 40...Circuit board of radio device 41.42.43 ...Connector 50...First amplifier 51...Second amplifier 52.
...Power supply circuit 53...Wireless section 54...Data processing section

Claims (2)

[Claims] (1) An antenna device for a small radio device, characterized by comprising at least two sets of short-circuited microstrip antennas having different excitation directions, and a connection means for connecting each of these antennas to a circuit system of the small radio device. . (2) A first antenna and a second antenna are provided, and the first antenna includes a block-shaped first dielectric, a first ground plate provided on one surface of the first dielectric, and the first dielectric. an antenna element provided on the other surface parallel to the surface on which the first ground plate is provided, and a shorting plate connecting the first ground plate and the antenna element at one end, and the second antenna is a block-shaped second dielectric, a second ground plate provided on one surface of the second dielectric, and a second ground plate provided on the other surface of the second dielectric that is parallel to the surface on which the second ground plate is provided. two sets of first antenna elements; two sets of second antenna elements respectively provided between the second base plate and the two sets of first antenna elements; and the second base plate and the first antenna element. Claim 1, characterized in that it has a first shorting plate that connects the second ground plane and the second antenna element at one end, and a second shorting plate that connects the second ground plane and the second antenna element at the other end. ) Antenna device for small radio equipment as described in item 2.