JPH1127030A - Planar antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar antenna which can vary its radiation directional pattern without changing its direction to freely perform communication with its opposite parties in various directions. SOLUTION: This planar antenna 10 consists of a conductive bottom board 13 which is grounded, a slender λ/2 antenna feeding element 11 which is placed within a virtual plane set opposite to the surface of the board 13 with a prescribed distance and in parallel to the said surface and is fixed to the board 13 by an insulated spacer 14, and the 1st and 2nd λ/2 antenna parasitic feeding elements 15a and 15b having substantially the same shape as the element 11 and placed at the right and left sides of the element 11 which can be switched between the 1st and 2nd positions having small and large distances from the element 11 respectively. When both elements 15a and 15b are fixed at the 1st position, the radiation directional pattern of the antenna 10 is large in the right and left directions shifted from its front. Meanwhile, the said pattern of the antenna 10 is large in its front direction when the elements 15a and 15b are fixed at the 2nd position. Thus, the position of the antenna 10 can be varied as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna, and more particularly, to a ground plane which is a grounded conductive plane plate, and an imaginary plane parallel to the ground plane and opposed to the ground plane by a predetermined distance. Elongate λ / 2 fixed to the base plate by a feed element insulator spacer
The present invention relates to a planar antenna having an antenna feed element.

[0002]

2. Description of the Related Art A conventional planar antenna of this type is shown in a plan view of FIG. 8A and a side view of FIG. 8B. In this planar antenna 50, a ground plate 53 is formed substantially at the center of a rectangular ground plate 53 formed of a conductor and grounded.
A λ / 2 antenna feed element 51 supported by an insulator spacer 54 is provided so as to keep a predetermined distance from the antenna spacer 54. In this case, 50Ω of the λ / 2 antenna feed element 51
A tap feeding point 52 is provided at a position where the matching can be achieved.

The above-described planar antenna 50 has a radiation directivity characteristic of an XY plane vertical polarization component as shown in FIG. 9A in the XY plane shown in FIG. 9B.
This planar antenna 50 is usually used in a situation as shown in FIG. That is, the planar antenna 50 is directly attached to the indoor side of the window, or is used by standing against the indoor side of the window.

[0004]

In the above-described use situation as shown in FIG. 10, when a communication partner, for example, a base station or a master station is located at point A, it can be understood from the characteristics of FIG. There is no problem in performing communication. However, when the other party to communicate with is located at point B, as can be seen from the characteristics of FIG.
0 itself needs to be directed to point B. However, there is a problem that the orientation of the planar antenna 50 cannot be adjusted to the point B depending on the situation of the place where the planar antenna 50 is used, for example, the situation where there is a large pillar in the direction of the point B. This becomes even more difficult in a planar antenna with a built-in repeater body.

The present invention has been made to solve the above-mentioned problem, and it is difficult to perform communication by changing the radiation directivity of the planar antenna without changing the direction of the planar antenna itself. An object of the present invention is to provide a planar antenna that enables good communication with a partner in a direction.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a ground plane, which is a conductive flat plate to be grounded, and the above-mentioned ground plane which is opposed to the ground plane by a predetermined distance. And an elongated λ / 2 antenna feed element fixed to the ground plane by a feed element insulator spacer, in the virtual plane by the parasitic element insulator spacer. Supported so as to be parallel to the λ / 2 antenna feed element at a position symmetrical with respect to the λ / 2 antenna feed element while keeping parallel to the longitudinal direction of the λ / 2 antenna feed element. Characterized in that it has a λ / 2 antenna parasitic element that can be arranged in a.

In the planar antenna 10 shown in FIG. 1, an elongated λ / 2 antenna feed element 11 is separated from a ground plane 13 by a predetermined distance and is parallel to the surface of the ground plane.
4 fixed to the base plate 13. On the left and right sides of the λ / 2 antenna feed element 11, insulator spacers 14a and 14b are provided so that first and second λ / 2 antenna parasitic elements 15a and 15b are parallel to the λ / 2 antenna feed element 11.
To the main plate 13. In this case, the insulator spacers 14a and 14b are configured to be guided by the moving slots 16 and to be able to move in parallel. In the planar antenna 20 shown in FIG. 4, the parallel movement is configured to be executed by the position changing mechanism 21.

The present invention also provides that the λ / 2 antenna feed element has substantially the same shape as the λ / 2 antenna feed element, and one λ / 2 antenna feed element is provided on each of the left and right sides of the λ / 2 antenna feed element. The parasitic spacer for the parasitic element is fixed so that it can be disposed at a first position near the λ / 2 antenna feed element, a second position far from the λ / 2 antenna feed element, and an intermediate position between the first position and the second position. Releasably fixed to the main plate.

In the planar antenna 10 shown in FIG. 1, a pair of λ / 2 antenna parasitic elements 15a and 15b have substantially the same shape as the λ / 2 antenna feed element 11, The left and right sides of the element 11 are guided by a moving slot 16 so as to be able to move in parallel, and the insulator spacers 14a and 14b are
6 is the first position, and the second position is where the insulator spacers 14a, 14b are in contact with the outermost of the moving slot 16. The planar antenna 10 has the characteristic shown in FIG. 2 at a first position and the characteristic shown in FIG. 3 at a second position. In the case of FIG. 4, the first and second positions are realized when the position setting lever 28 is pulled out and pushed in.

[0010] Further, according to the present invention, the two λ / 2 antenna parasitic elements are fixed at the first and second positions and at an intermediate position between them by a position setting mechanism arranged on the back surface of the base plate. In this case, the position setting mechanism is movably disposed along the back surface of the base plate, and is formed in the base plate in a direction orthogonal to a longitudinal direction of the λ / 2 antenna feed element. The two λ / 2 antenna parasitic elements are respectively coupled to the two λ / 2 antenna parasitic elements by the parasitic element insulator spacers penetrating the long holes, and the two λ / 2 antenna parasitic elements are respectively attached to the surface of the base plate. First and second moving plates which are held so as to be able to move in parallel;
First and second motion direction conversion plates respectively mounted on terminals inside the moving plate, and a back surface of the base plate so as to be able to reciprocate at right angles to the moving direction of the first and second moving plates. And a position setting lever having one end axially attached to the other end of the first and second motion direction conversion plates.

In the planar antenna 20 shown in FIG. 4, a position changing mechanism 21 is arranged on the back side of the base plate 13. When the position setting lever 28 is reciprocated, the first and second movement direction conversion plates 29a and 29b convert the reciprocation into left and right movements, and the first and second movement plates 25a and 29b.
a, 25b are moved left and right. Therefore, the case where the position setting lever 28 is pulled out most corresponds to the first position, and the case where the position setting lever 28 is pushed in and the first and second movement direction conversion plates 29a and 29b are aligned is the second position. Corresponds to position.

Further, the present invention provides a ground plane, which is a conductive flat plate grounded, and is disposed in an imaginary plane parallel to the ground plane, which is opposed to the ground plane surface by a predetermined distance and which is parallel to the ground plane. A planar antenna having an elongated λ / 2 antenna feed element fixed by a feed element insulator spacer, wherein the λ / 2 antenna feed element is supported by the parasitic element insulator spacer so as to be in the virtual plane; While keeping parallel to the longitudinal direction of
Two or more pairs of λ / 2 antenna parasitic elements fixed in parallel with the λ / 2 antenna feed element at symmetrical positions with respect to the / 2 antenna feed element;
A parasitic element changeover switch that is connected between each terminal of the antenna parasitic element and the ground plane, and that connects or disconnects between the terminal of each of the λ / 2 antenna parasitic elements and the ground plane according to a switching instruction; , The two or more λ
The selected pair of the / 2 antenna parasitic elements is selected, the space between the selected pair of λ / 2 antenna parasitic elements and the ground plane is cut, and the other pair of λ / 2 antenna parasitic elements is disconnected. A switching control circuit that outputs the switching instruction to the parasitic element switching switch so as to connect to the ground plane.

In the planar antenna 30 shown in FIG.
The two pairs of λ / 2 antenna parasitic elements 35a and 35 are symmetrically arranged in parallel with the two-antenna feed element 31 on the ground plate 33.
b; 35c and 35d are fixedly arranged. These λ /
Two-antenna parasitic elements 35a, 35b; 35c, 35d
A parasitic element changeover switch 37 shown in FIG. 6 is provided between both terminals in the longitudinal direction of the
A switching control circuit controls an element switching circuit 39 in which these parasitic element switching switches 37 are connected as shown in FIG. 7, so that the λ / 2 antenna parasitic element 35 at the first position is controlled.
a, 35b or only one pair of the λ / 2 antenna parasitic elements 35c, 35d at the second position is enabled, and λ
The position of the / 2 antenna parasitic element is electrically changed.

Further, in the present invention, each of the parasitic element changeover switches includes a diode having an anode connected to the terminal of the λ / 2 antenna parasitic element, a cathode connected to the ground plane, and one end connected to the diode. The anode includes a coil having the other end connected to the switching control circuit, and a capacitor having one end connected to the switching control circuit and the other end connected to the ground plane, respectively.

Parasitic element changeover switch 3 shown in FIG.
7, the anode is a λ / 2 antenna parasitic element 3
5a, 35b; terminals of 35c, 35d; a diode D1 having a cathode connected to the ground plate 33; a coil L1 having one end connected to the anode of the diode D1 and the other end connected to the switching control circuit; A capacitor C having the other end connected to the ground plane 33 is connected to the control circuit.
And 1.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a plan view showing a planar antenna according to a first embodiment of the present invention.
1 (b) is a side view of FIG. 1 (a), and FIG.
It is a front view of (a). In this planar antenna 10, an insulator spacer is provided substantially at the center of a ground plane 13, which is a rectangular flat plate formed of a conductor and grounded, parallel to the surface of the ground plane 13 and at a predetermined distance from the ground plane 13. A λ / 2 antenna feed element 11 supported by 14 (made of non-metallic Teflon or Duracon) is arranged. In this case, the tap feed point 1 is located at a position where the λ / 2 antenna feed element 11 can be matched with 50Ω.
2 are provided.

On the left and right sides of the λ / 2 antenna feed element 11, first and second λ / 2 antenna parasitic elements 15 a and 15 b having the same shape as the λ / 2 antenna feed element 11 are provided.
They are arranged symmetrically with respect to the antenna feed element 11. These first and second λ / 2 antenna parasitic elements 15a and 15b are insulated spacers so as to be parallel to the surface of the ground plate 13 and maintain the same distance from the ground plate 13 as the λ / 2 antenna feed element 11. 14a and 14b respectively. That is, the λ / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 15a and 15b are arranged in parallel in a virtual plane parallel to the surface of the base plate 13.

First and second λ / 2 antenna parasitic element 1
Insulator spacers 14a, 1 supporting 5a, 15b
The lower end of 4b is a moving slot 1 drilled in the main plate 13.
6 can be fixed at an appropriate position within a predetermined distance range by a fastener (not shown: including, for example, a non-metallic plastic screw or the like) and a position changing mechanism (described later) disposed on the back surface of the base plate 13 through the base plate 13. Have been. Therefore, once the insulator spacers 14a and 14b are fixed, if the fastener is loosened, the insulator spacers 14a and 14b can be moved in the left and right direction by being guided by the moving slot 16, and if the fastener is tightened at a desired position, the insulating spacers 14a and 14b can be insulated. The body spacers 14a, 14b can be fixed there.

With the structure as described above, the frequency is 1.9 GHz.
In one specific example of the planar antenna that handles the signals of the above, the base plate 13 has a B5 size and the insulator spacers 14 and 1
4a and 14b are sized to hold the λ / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 15a and 15b, respectively, at 7 millimeters (mm) from the surface of the base plate 13, It is fixed to the base plate 13 with a plastic screw or the like. The first and second λ / 2 antenna parasitic elements 15a and 15b are located on the innermost side of the moving slot 16,
That is, when the antenna is fixed at the position closest to the λ / 2 antenna feed element 11 (FIG. 1A), the λ / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 1
The distance between 5a and 15b is 35 mm.

The first and second λ / 2 antenna parasitic elements 15a and 15b are located on the outermost sides of the moving slot 16,
That is, when the antenna is fixed at the farthest position from the λ / 2 antenna feed element 11, the λ / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 15a and 15b are fixed.
Are 55 mm each. Needless to say, these dimensions should be appropriately changed depending on the frequency of the signal to be handled.

When the distance between the λ / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 15a and 15b is set to 55 mm, the above-mentioned planar antenna 10 has the configuration shown in FIG. In the XY plane shown by (b), it has radiation directivity characteristics of vertical polarization components on the XY plane as shown in FIG. In addition, the planar antenna 10 has λ
When the distance between the / 2 antenna feed element 11 and the first and second λ / 2 antenna parasitic elements 15a and 15b is set to 35 mm, the XY shown in FIG.
It has a radiation directivity characteristic of a vertically polarized component on the XY plane as shown in FIG.

Therefore, in FIG. 2A, the beam is directed in the front direction, and is suitable for communication with the other party at the point A in the use situation as shown in FIG. 10), the beams are separately directed in the directions of ± 50 ° to the left and right, and are suitable for communication with the other party at the point B in FIG. As described above, the planar antenna 10 can communicate well with the communication partner in various directions by changing the positions of the λ / 2 antenna parasitic elements 15a and 15b without changing the direction of the planar antenna 10 itself. Can be.

Second Embodiment Next, a second embodiment in which a position changing mechanism capable of easily changing the positions of the λ / 2 antenna parasitic elements 15a and 15b is arranged will be described with reference to FIGS.
This will be described with reference to FIG. In this planar antenna 20, the front side of the base plate 13 is the same as that shown in FIG. 1, but a position changing mechanism 21 is arranged on the back side of the base plate 13. As shown in FIGS. 4A and 4B, the position changing mechanism 21 includes first and second moving plates 25a,
25b, the first and second movement direction changing plates 29a,
29b and a position setting lever 28.

First and second moving plates 25a, 25b
Are arranged so as to move in parallel while sliding left and right on the back side of the base plate 13. The longitudinal ends of the first and second moving plates 25a and 25b immediately below the moving slot 16 are coupled to the lower ends of the insulator spacers 14a and 14b through the moving slot 16 respectively. When the second moving plates 25a and 25b move, λ
The / 2 antenna parasitic elements 15a and 15b also move while keeping parallel to the λ / 2 antenna feed element 11.

First and second movement direction changing plates 29
a and 29b are connected to the ends of the tab portions, one of which extends from the central portion of the first and second moving plates 25a and 25b to the center of the base plate 13 by connecting shafts 26a and 26b (pivotally rotatably connected). ) Has been. Position setting lever 2
Reference numeral 8 is arranged so as to be guided by a guide shaft 27a at a central portion of the main plate 13 and to be able to move at right angles to the moving directions of the first and second moving plates 25a and 25b. The end of the position setting lever 28 on the central portion side of the main plate 13 is pivotally attached to the other ends of the first and second motion direction changing plates 29a and 29b by a connecting shaft 27b.

Since the position changing mechanism 21 is configured as described above, when the position setting lever 28 is pushed to the innermost position, the first and second movement direction changing plates 29a and 2 are moved.
9b rotates around the connecting shafts 26a and 26b and the connecting shaft 27b, aligns with the tab portions of the first and second moving plates 25a and 25b, and provides the λ / 2 antenna parasitic element 1
5a and 15b are set farthest from the λ / 2 antenna feed element 11 (FIG. 4A). In this case, the radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna 20 are as follows:
This is the same as that shown in FIG.

When the position setting lever 28 is pulled out to the end, the first and second movement direction changing plates 29a, 29
b rotates around the connecting shafts 26a and 26b and the connecting shaft 27b, pulls in the tab portions of the first and second moving plates 25a and 25b, and moves the first and second λ / 2 antenna parasitic elements 15a. , 15b to the λ / 2 antenna feed element 1
It is set to the position closest to 1 (FIG. 4B). In this case, the radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna 20 are the same as those shown in FIG.

As described above, the first and second λ / 2 antenna parasitic elements 15a and 15b can be easily set at two desired positions only by reciprocating the position setting lever 28, but this is necessary. If so, the position setting lever 28 is stopped at a position intermediate between these two positions, so that the first and second λ / 2 antenna parasitic elements 15a and 15b are set at appropriate intermediate positions. It goes without saying that the radiation directivity characteristic corresponding to the position can be obtained.

Embodiment 3 Next, an embodiment provided with an element switching circuit capable of electrically changing the arrangement of the λ / 2 antenna parasitic element shown in FIGS. 1 and 4 by a parasitic element switch. Regarding the form 3 of FIG.
This will be described with reference to (b) and (c). The planar antenna 30 is configured to handle a signal having a frequency of 1.9 GHz as an example.
It is 5 size. The insulator spacer 34 connects the λ / 2 antenna feed element 31 having the feed point 32 to the ground plane 33.
At the center at a height of 7 mm from the surface.

The insulator spacers 34a and 34b are
First and second λ / 2 antenna parasitic elements 35a and 35b
At a height of 7 mm from the surface of the main plate 33, and λ / 2
Λ / 35 mm away from the antenna feed element 31
It is held in parallel with the two-antenna feed element 31. The insulator spacers 34c and 34d are the third and fourth λ
The / 2 antenna parasitic elements 35c and 35d are respectively placed at a height of 7 mm from the surface of the base plate 33 and at a distance of 55 mm from the λ / 2 antenna feed element 31 at the first and second λ / 2.
It is held in parallel with the antenna parasitic elements 35a and 35b.

Each of the first, second, third, and fourth λ / 2 antenna parasitic elements 35a, 35b, 35c, and 35d is provided with a parasitic element shorting pin 36 at each end thereof. The short-circuit pin 36 is connected to the connection terminal ANT of the parasitic element switch 37 shown in FIG. FIG.
The parasitic element changeover switch 37 has an anode connected to a connection terminal.
In ANT, the cathode is ground (in this case, ground plate 3
3), a coil L1 having one end connected to the connection terminal ANT, another end connected to the control terminal VC, and a capacitor having one end connected to the control terminal VC and the other end connected to the ground. C1.

FIG. 7 shows the parasitic element changeover switch 3 described above.
FIG. 7 is a diagram illustrating an element switching circuit including No. 7; 1st, 2nd
The control terminal VC of the parasitic element changeover switch 37 provided at both terminals of the λ / 2 antenna parasitic elements 35a and 35b is commonly connected to the first switching control terminal VC1. The control terminals VC of the parasitic element changeover switches 37 provided at both terminals of the third and fourth λ / 2 antenna parasitic elements 35c and 35d are commonly connected to the second switching control terminal VC2. ing.

Accordingly, when a switching control circuit (not shown) applies a positive voltage to the first switching control terminal VC1 and a negative voltage to the second switching control terminal VC2, respectively, the first and second λ / Both terminals of the two antenna parasitic elements 35a and 35b are short-circuited and disabled via the diode D1 and the ground, and both terminals of the third and fourth λ / 2 antenna parasitic elements 35c and 35d. Are enabled by being released from the ground. In this case, the radiation directivity characteristic of the XY plane vertical polarization component of the planar antenna 30 is as shown in FIG.
It becomes the same as that shown in.

Contrary to the above case, when the switching control circuit applies a negative voltage to the first switching control terminal VC1 and a positive voltage to the second switching control terminal VC2, respectively, Both terminals of each of the λ / 2 antenna parasitic elements 35a and 35b are enabled by being released from the ground, and both terminals of the third and fourth λ / 2 antenna parasitic elements 35c and 35d are each connected to a diode. Shorted via D1 and ground and disabled. In this case, the radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna 30 are as shown in FIG.
It becomes the same as that shown in.

In the above-described planar antenna 30, λ /
2 antenna parasitic element is changed from λ / 2 antenna feed element to 3
Although it can be set at any position of 5 mm or 55 mm, if a λ / 2 antenna parasitic element is further arranged in the middle of them and only the middle one is made effective,
It goes without saying that an intermediate characteristic between the two positions described above is obtained. It is also clear that if necessary, all the λ / 2 antenna parasitic elements can be disabled to form a conventional planar antenna as shown in FIG.

[0036]

As described in detail above, the planar antenna according to the present invention comprises a ground plane, which is a conductive flat plate to be grounded, and the above-mentioned ground plane which is opposed to the ground plane by a predetermined distance. A planar antenna having an elongated λ / 2 antenna feed element disposed in a parallel virtual plane and fixed to the ground plane by a feed element insulator spacer, wherein the parasitic antenna is in the virtual plane by the parasitic element insulator spacer. So as to be parallel to the longitudinal direction of the λ / 2 antenna feed element and to be parallel to the λ / 2 antenna feed element at a position symmetrical about the λ / 2 antenna feed element. Λ that can be arranged
By having the / 2 antenna parasitic element, if the position of the λ / 2 antenna parasitic element is appropriately changed without changing the direction of the planar antenna itself, the radiation directivity characteristic with respect to the direction of the communication partner can be obtained. Can be set to be good, and there is an effect that usability is improved.

Further, the planar antenna according to the present invention comprises:
The λ / 2 antenna parasitic elements are arranged one by one on the left and right sides of the λ / 2 antenna feed element, and can be freely set between the first position and the second position. Easy to set.

Further, the planar antenna according to the present invention comprises:
A position setting mechanism for changing the position of the pair of λ / 2 antenna parasitic elements is provided, and the position of the λ / 2 antenna parasitic element can be changed only by reciprocating the position setting lever of the position setting mechanism. This makes it possible to very easily and accurately change the position of the λ / 2 antenna parasitic element.

Further, according to the present invention, two or more pairs of λ / 2 antenna parasitic elements are arranged, and parasitic element changeover switches are arranged between both ends thereof and the ground plane, respectively, and a parasitic control element is appropriately provided by a switching control circuit. The position of the λ / 2 antenna parasitic element is mechanically moved and changed by setting the element switch to ON or OFF and enabling only a desired pair of the λ / 2 antenna parasitic elements. If not, they can be changed electrically.

Further, according to the present invention, since the parasitic element selector switch is composed of a diode, a coil and a capacitor, the configuration is simple, the parts can be easily obtained, and the configuration can be made at a low cost.

[Brief description of the drawings]

1A is a plan view showing a planar antenna according to Embodiment 1 of the present invention, FIG. 1B is a side view of FIG.
(C) is a front view of (a).

FIG. 2A is a plan view of the planar antenna of FIG.
FIG. 9 is a diagram showing radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna of FIG. 1 when the second λ / 2 antenna parasitic element is set at a position farthest from the λ / 2 antenna feed element; 2B is a diagram illustrating the XYZ-axis directions of the planar antenna of FIG.

FIG. 3A is a plan view of the planar antenna of FIG.
FIG. 7B is a diagram showing the radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna of FIG. 1 when the second λ / 2 antenna parasitic element is set closest to the λ / 2 antenna feed element; 2) is a diagram showing the XYZ-axis directions of the planar antenna of FIG.

FIG. 4A is a plan view showing a state in which a position setting lever is pushed to the innermost position of the planar antenna according to the second embodiment of the present invention, and FIG. 4B is a state in which the position setting lever is pulled out to the end; It is a top view showing a state.

5A is a plan view showing a planar antenna according to Embodiment 3 of the present invention, FIG. 5B is a side view of FIG. 5A, and FIG.
2 is a front view of FIG.

FIG. 6 is a circuit diagram illustrating a parasitic element changeover switch in the planar antenna of FIG. 5;

FIG. 7 is a circuit diagram showing an element switching circuit in the planar antenna of FIG.

FIG. 8A is a plan view showing a conventional planar antenna,
(B) is a side view of (a).

9A is a diagram showing the radiation directivity characteristics of the XY plane vertical polarization component of the planar antenna of FIG. 8, and FIG. 9B is a diagram showing the XYZ axis directions of the planar antenna of FIG.

FIG. 10 is a diagram illustrating a situation where a planar antenna is used.

[Explanation of symbols]

 10, 20, 30 Planar antenna 11, 31 λ / 2 antenna feed element 12, 32 Feed point 13 Ground plane 14, 14a, 14b Insulator spacer 15a First λ / 2 antenna parasitic element 15b Second λ / 2 antenna Parasitic element 16 Moving slot 21 Position change mechanism 25a First moving plate 25b Second moving plate 26a, 26b, 27b Connecting shaft 27a Guide shaft 28 Position setting lever 35a First λ / 2 antenna parasitic element 35b No. 2 λ / 2 antenna parasitic element 35 c Third λ / 2 antenna parasitic element 35 d Fourth λ / 2 antenna parasitic element 36 parasitic element shorting pin 37 parasitic element switching switch 39 element switching circuit VC control terminal VC1 first switching control terminal VC2 second switching control terminal

Claims (5)

[Claims] 1. A ground plane, which is a conductive plane plate grounded, and disposed in an imaginary plane facing the surface of the ground plane and separated from the ground plane by a predetermined distance and parallel to the surface. Elongated λ / fixed by body spacer
A planar antenna having two antenna feed elements, the antenna being supported by the parasitic element insulator spacer so as to be in the virtual plane, keeping parallel to the longitudinal direction of the λ / 2 antenna feed element, and Λ / 2 which can be arranged in parallel with the λ / 2 antenna feed element at a position symmetrical with respect to the ア ン テ ナ antenna feed element.
A planar antenna comprising an antenna parasitic element. 2. The λ / 2 antenna feed element has substantially the same shape as the λ / 2 antenna feed element.
The λ / 2 antenna feed elements are arranged on the left and right sides of the
A first position close to the / 2 antenna feed element and the λ / 2
2. The planar antenna according to claim 1, wherein the parasitic element insulator spacer is releasably fixed to the base plate so as to be disposed at a second position far from the antenna feed element and at an intermediate position between the second position and the intermediate position. 3. The two λ / 2 antenna parasitic elements are fixed at the first and second positions and at a position intermediate between them by a position setting mechanism disposed on a back surface of the base plate. In this case, the position setting mechanism is movably disposed along the back surface of the main plate, and the λ / 2
The two λ / 2 antenna parasitic elements are respectively connected to the two λ / 2 antenna parasitic elements by the parasitic element insulator spacers penetrating through a long hole formed in the ground plane in a direction orthogonal to the longitudinal direction of the antenna feeding element. First and second moving plates for holding the two λ / 2 antenna parasitic elements so as to be able to move in parallel with respect to the surface of the ground plate, respectively; A first and a second movement direction changing plate pivotally mounted on terminals inside the second movement plate, and the base plate so as to be able to reciprocate at right angles to the movement direction of the first and second movement plates. 3. The planar antenna according to claim 2, further comprising: a position setting lever disposed on a back surface of the first and second moving direction changing plates and having one end pivotally attached to the other end of the first and second motion direction conversion plates. 4. A ground plane, which is a conductive flat plate to be grounded, and disposed in a virtual plane facing the surface of the ground plane and separated from the ground plane by a predetermined distance and parallel to the surface. Elongated λ / fixed by body spacer
A planar antenna having two antenna feed elements, the antenna being supported by the parasitic element insulator spacer so as to be in the virtual plane, keeping parallel to the longitudinal direction of the λ / 2 antenna feed element, and At least two pairs of λ / 2 fixed in parallel with the λ / 2 antenna feed element at positions symmetrical with respect to the ２ antenna feed element.
An antenna parasitic element, connected between each terminal of each of the λ / 2 antenna parasitic elements and the ground plane, and connected between a terminal of each of the λ / 2 antenna parasitic element and the ground plane by a switching instruction; A parasitic element change-over switch for connecting or disconnecting, a selected pair of the two or more λ / 2 antenna parasitic elements, and selecting the selected pair of λ / 2 antenna parasitic elements and the ground plane. And the other pair of λ /
A planar antenna, comprising: a two-antenna parasitic element; and a switching control circuit that outputs the switching instruction to the parasitic element selector switch so as to connect between the parasitic element and the ground plane. 5. Each of the parasitic element changeover switches has an anode connected to a terminal of the λ / 2 antenna parasitic element, a cathode connected to the ground plate, and one end connected to an anode of the diode. 5. The planar antenna according to claim 4, comprising a coil having an end connected to the switching control circuit, and a capacitor having one end connected to the switching control circuit and the other end connected to the ground plane.