JPH01316005A - Flat plate antenna - Google Patents

Abstract

PURPOSE:To easily set the resonance frequency of the antenna, to make the interval between a ground conductor and a radiation conductor constant and to attain the adjustment of the resonance frequency thereby making the antenna small in size by providing a reactance variable means varying the reactance to a short-circuit plate connecting part of one end face of the radiation conductor to the ground conductor. CONSTITUTION:The radiation conductor 2 and the ground conductor 3 of the flat plate antenna comprising a printed circuit board or the like are manufactured by a metallic die, the short-circuit plate 4 is composed of a printed circuit board 9 and a copper foil 9a formed by etching is used as the short-circuit plate 4. Moreover, the width of the printed circuit board 9 itself is made slightly wider than the width of the copper foil part 9a and the width S of the copper foil part 9a is set optionally on the printed circuit board 9. Furthermore, a recessed part 10 is formed on the upper part of the printed circuit board 9, a lock piece 11 of L-shape fitted to the recessed part 10 is formed to the edge of the radiation conductor 2 and the locked piece 11 is placed at the outside of the copper foil part 9a and connected, the lower part of the printed circuit board 9 is fitted to the ground conductor 3 and connected to the copper foil 9a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a flat plate antenna formed of a printed board or the like.

[Prior Art] As shown in FIG. 25, a basic flat plate antenna is constructed by etching a rectangular open planar circuit radiating element 2a on a thin printed board 5. The conductor on the lower surface is a ground conductor 3, and a predetermined portion of the radiating element 2a with a dielectric 6 sandwiched therebetween is supplied with power α1. Since the printed board 5 has dielectric loss, in order to increase the antenna efficiency, we use air that does not cause any loss, and replace the etched radiation element 2a with the radiation conductor 2, which is a plate-shaped metal plate. Toshide is here.

Furthermore, as shown in Fig. 26, it is known that the radiation pattern and antenna efficiency of this flat plate antenna do not change even if a one-sided short-circuited antenna system is constructed using the short-circuit plate 4, and the same frequency Therefore, it is possible to construct the device with a size that is less than half of the normal size.

[Problem to be Solved by the Invention 1] It goes without saying that as the radiation conductor becomes smaller, the grounding conductor can also be made smaller, and the antenna as a whole can be made smaller. However, in general, if the antenna gain (efficiency) is maintained and the overall antenna is made smaller, the bandwidth becomes smaller. This flat plate antenna is no exception; its band width has become narrower due to miniaturization, and it has the following problems.

■ If the dimensions of each part of the antenna are fixed, it can only be used within a specific narrow frequency range, and it cannot be shared between two or more frequencies.

■ If you try to use it at a different frequency that is a little further away, you will need another mold, which will increase the cost.

■ Due to tolerances in the dimensions of each part of the antenna during mass production, the resonant frequency of the antenna itself varies, and since it is a narrow band, it does not fit within the band and requires adjustment, but there is no adjustment method.

■ If the dimensions of the radiating conductor, grounding conductor, and shorting plate are fixed, they will resonate only at a certain frequency and cannot be used at other frequencies.

The present invention has been provided in view of the above points, and it is possible to freely set the resonant frequency of the antenna by changing the reactance on the shorting plate side without changing the sizes of the ground conductor and the radiation conductor. The objective is to provide a flat plate antenna for this purpose.

[Means for Solving the Problems] The present invention provides a radiating conductor having a feeding point at a predetermined point, a grounding conductor arranged parallel to the radiating conductor, and a part of one end surface of the radiating conductor being made into a grounding conductor. In a flat plate antenna consisting of a connecting short-circuit plate, the short-circuit plate is provided with a reactance change means for varying the reactance.

[Function] By changing the reactance on the shorting plate side, the resonant frequency of the antenna can be freely set.

[Example 1] Hereinafter, an example of the present invention will be described with reference to the drawings. Fifth
The figure shows a further miniaturization of the conventional flat antenna, in which the width of the shorting plate 4 is made narrower than the width of the radiating conductor 2, giving the effect of adding equivalent inductance to the base of the radiating conductor 2. , the length of the radiation conductor 2 can be shortened.

This is the basic form of the present invention, in which the ground conductor 3 and the radiation conductor 2 are arranged in parallel through an air layer, the upper end of the narrow shorting plate 4 is connected to one end surface of the radiation conductor 2, and the lower end is connected to one end surface of the radiation conductor 2. is connected to the ground conductor 3. FIG. 6 shows a cross-sectional view in this case, in which the connector 7 is connected to the power supply point 1 via the power supply #8. In the flat plate antenna shown in FIG. 7, which is composed of a radiating conductor 2, a shorting plate 4, and a grounding conductor 3, the relationship between the width S of the shorting plate 4 and the resonant frequency f' is determined experimentally.
The results shown in the figure were obtained. If the width of the radiation conductor 2 is 1), then S=1, that is, the entire end surface of the radiation conductor 2 is connected to the shorting plate 4.
The resonant frequency when connected to the ground conductor 3 by f. @ of the shorting plate 4 for @1) of the radiation conductor 2
This is a graph of the ratio S/(] of S and the resonance frequency ratio fr/flI based on the frequency f (+) in the case of 5=1.

From the graph shown in FIG. 8, it can be seen that changing the width S of the shorting plate 4 changes the resonant frequency of the antenna. In this equivalent antenna, a dielectric (relative dielectric εr=2°55) is present between the radiation conductor 2 and the ground conductor 3, but it goes without saying that this tendency does not change even if this is air. That is, it can be seen that the resonance frequency of the antenna can be freely adjusted and set by equivalently arbitrarily adjusting and setting @S of the shorting plate 4, or by making it possible to make an MIt structure. In addition, by arbitrarily changing the width S of the shorting plate 4,
This constitutes reactance variable means.

By the way, when mass producing this flat plate antenna, a mold is required. Changing the antenna structure itself, that is, changing the mold every time the frequency is changed, increases the cost. Therefore, if the width of the shorting plate 4 is changed equivalently without changing the dimensional structure of the radiation conductor 2 and the grounding conductor 3 themselves, the frequency can be easily changed, and the molds of the radiation conductor 2 and the grounding conductor 3 can be changed. You won't have to do it. As a method for equivalently changing the width of the shorting plate 4, the present invention uses the following method.

That is, the radiation conductor 2 and the ground conductor 3 are manufactured using a mold. As shown in FIG. 1, the shorting plate 4 is composed of a printed board 9, and has a copper foil portion 9a formed by etching.
(The shaded area in the figure) is used as the short circuit plate 4. The width of the printed board 9 itself is made slightly larger than the width of the copper foil portion 9a as the short circuit board 4, and the copper foil portion 9a is placed on the printed board 9.
The width can be set to any size. 'Kg S1 of this copper foil part 9a. can be arbitrarily set as shown in FIGS. 4(a) to 4(c). Incidentally, FIG. 3 shows a perspective view of the printed board 9. A four part 10 is formed on the upper part of the printed board 9, and an L-shaped locking piece 11 that fits into the four part 10 is formed at the end of the radiation conductor 2.
are located outside the copper foil portion 9a of the printed board 9 and are connected in contact with each other. Further, the lower part of the printed board 9 is fitted into the ground conductor 3 to contact and connect the copper foil portion 9a. Note that the radiation conductor 2, the ground conductor 3, and the shorting plate 4 are each constructed from separate members.

With this configuration, by appropriately designing the etching width of the copper foil portion 9a serving as the shorting plate 4, a single mold for molding the printed board 9 can be used to handle various frequencies. That is, a radiation conductor 2, a grounding conductor 3, a shorting plate 4
There is only one gold plate 14 for each, and the width of the shorting plate 4 can be varied by etching to freely set the resonant frequency of the antenna.

[Example 2] Next, Example 2 will be described. As shown in FIG. 9, the radiation conductor 2 and the shorting plate 4 are integrally constructed of one metal plate, and the lower part of the shorting plate 4 is fixed to the grounding conductor 3. The ground conductor 3 is made of a printed board, and the copper foil portion of the printed board is used as the ground conductor 3. In FIG. 10 viewed from the ground conductor 3 side, a part of the short circuit plate 4 is connected to the ground conductor 3, and the other end of the short circuit plate 4 is connected to the ground conductor 3 via a switching circuit 12. As shown in FIG. 11, the switching circuit 12 is composed of a high-frequency switching diode D1, a resistor R1, and a capacitor C1. When a voltage of 5\l is applied to the control terminal Tc, the diode D moves in the forward direction. It is biased and has an electrical resistance of approximately 0Ω. That is, as shown in FIG. 12(a), the terminals T and T2 are connected. On the other hand, 0
When ■ is applied, diode D1 becomes reverse biased,
The electrical resistance becomes extremely large, and the terminals 1'1 and T2 become open as shown in FIG. 12 (11).

Note that the resistor R1 limits the current flowing to the diode D1, and the capacitor CI cuts off the direct current from the terminal T2.The capacitance of the capacitor C1 is sufficiently large, and its impedance can be almost ignored in the frequency band used. Therefore, the impedance between terminals 1' and 'I'2 is determined by the impedance of diode D1.

A large number of such switching circuits 12 are provided between the shorting plate 4 and the ground conductor 3. In this embodiment, the number of switching circuits 12 is one, but any number may be provided.

When the switching circuit 12 is in the on state, the shorting plate 4 and the ground conductor 3 are electrically connected, which corresponds to the width of the shorting plate 4 being equivalently increased, and the contact area between the shorting plate 4 and the grounding conductor 3 becomes equivalently larger, and the frequency becomes higher than in the previous graph. Conversely, when turned off, the frequency becomes lower.

In this way, by appropriately turning on and off the switching circuit 12, the resonant frequency of the antenna can be controlled. Then, by switching and using the two frequencies by switching control of the switching circuit 12, for example,
One frequency can be switched and used as a reception frequency and the other as a transmission frequency, and antenna efficiency can be improved. Furthermore, it is possible to switch and use frequency variability so as to resonate with each frequency.

[Example 3] Next, Example 3 will be described. In FIG. 13, the printed board 9 shown in FIG. 1 is used, and a slit 13 separating the radiation conductor 2 side and the ground conductor 3 side is formed in the copper foil part 9a, which is the shorting plate 4 of the printed board 9. Formed in the same direction as the surface,
A low impedance element is connected between the copper foil portions 9a so as to straddle this slit 13. One end of the slit 13 is open, and the other end is connected through a copper foil portion 9a, and a chip resistor 14 is used as a low impedance element. This resistor 14 has a resistance value of OΩ as a low impedance element at high frequencies. 1st
3 shows a state in which the resistor 14 is mounted so as to straddle the slit 13, and FIG. 14 shows a cross-sectional view. Further, FIG. 15 shows a front view and a perspective view of the printed board 9.

When the resistor 14 is mounted in the position shown in FIG. 16 (+1), the width of the shorting plate 4 becomes equivalently larger as shown in FIG. will also be lower. Furthermore, if another resistor 14 is mounted as shown in FIG. 17(a), the width of the shorting plate 4 becomes even larger as shown in FIG. 17(1), and the resonant frequency becomes even lower.

In this way, in order to change the width of the shorting plate 4 etched on the copper foil portion 9a of the printed board 9, the chip type resistor 1 can be changed without changing the copper foil portion (pattern) 9a of the printed board 9.
By appropriately implementing 4, it is possible to support any frequency.

[Example 4] FIGS. 18 to 24 show Example 4, in which the printed board 9
A slit 15 is formed to divide the copper foil portion 9a into two, and a circular plate 16 having a copper foil portion 1.6a formed on the side of the copper foil portion 9a is provided at the center of the slit 15. The disk 16 is made of an insulating material and has a copper foil portion 16a formed on one side, and the copper foil portion 16a changes the area where the upper and lower copper foil portions 98 of the printed board 9 are joined depending on the rotational position of the disk 16. ing.

The disk 16 is rotatable by, for example, a sleeve on the printed board 9, and the copper foil portion 16a of the disk 16 and the copper foil portion 9a of the printed board 9 are brought into close contact. When the disk 16 is rotated to the position shown in FIG. 23, the bonding area of the upper and lower copper foil portions 9a of the printed board 9 becomes small, and the width of the shorting plate 4 becomes equivalently narrow. Furthermore, when the position of the disc 16 is rotated to the position shown in Fig. 24, the joint area changes, and the width of the shorting plate 4 becomes equivalently wider as shown in Fig. 24 (b), and the resonant frequency increases. It gets lower. In this way, by rotating the disk 16, the bonding area of the copper foil portion 16a changes, and the width of the shorting plate 4 changes, and accordingly, the resonance frequency can be changed. is possible.

[Effect of the Invention J As described above, the present invention includes a radiating conductor having a feeding point at a predetermined point, a grounding conductor arranged parallel to this radiating conductor, and a part of one end surface of the radiating conductor being made into a grounding conductor. In a flat plate antenna consisting of a connecting short-circuit plate, the short-circuit plate is equipped with a reactance variable means for varying the reactance, so the resonant frequency of the antenna can be freely and easily set by changing the reactance on the short-circuit plate side. In addition, since the reactance on the shorting plate side is only changed, the radiation conductor and the ground conductor can be shared, and the resonant frequency can be adjusted by keeping the distance between the ground conductor and the radiation conductor constant. This has the advantage that it can be made smaller and that cases and the like can be shared.

The reactance can be easily varied by changing the width of the shorting plate, and the resonant frequency can also be easily varied.In addition, using a switching element, the amount of connection between the shorting plate and the radiation conductor can be adjusted by turning the switching element on and off to adjust the resonance frequency. Furthermore, it is possible to short-circuit or open the conductors of the printed board through the slit formed in the short-circuiting plate, or change the number and continuous open area between the conductors by changing the rotational position of the disc, in the same way as above. The resonant frequency can be easily adjusted.

In addition, since the radiation conductor, ground conductor, shorting plate, etc. are separate parts, the radiation conductor and the ground conductor can be shared, and
Since the shorting plate is made of a printed board, the adjustment and manufacturing of the shorting plate is facilitated.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of essential parts of a flat plate antenna according to Embodiment 1 of the present invention, Fig. 2 is a sectional view of the same as above, Fig. 3 is a perspective view of a printed board same as above, and Figs. 4 (,) to (c). Figure 5 is a perspective view of the short-circuited flat plate antenna for air layer, which is the basis of the present invention, Figure 6 is a sectional view of the same as the above, and Figure 7 is the same as the above. FIG. 8 is a perspective view of the flat antenna for evaluation, FIG.
Fig. 1 is a circuit diagram of the switching circuit same as the above, Fig. 12 is an explanatory diagram of the same as the above, Fig. 13 is a perspective view of the main part of the third embodiment of the same, Fig. 14 is a sectional view of the main part of the same as the above, and Fig. 15 is (a)(1
1) is a front view and a perspective view of the printed board of "2", No. 16
Figure 17 is an explanatory diagram of the same operation as above, Figure 18 is a perspective view of the main part of Example 4 as above, Figure 19 is a front view of the printed board as above, Figure 20 (a) (+1) is as above. Figure 21 (a) (+1) is a rear view and cross-sectional view of the same disk as above, Figure 22 (a) (+1) is when the disk is mounted on a printed board. 23 and 1. F. FIG. 24 is an explanatory diagram of the same operation as above, FIG. 25 is a perspective view of a conventional flat plate antenna, and FIG. 26 is a perspective view of a one-sided type flat antenna same as above. DESCRIPTION OF SYMBOLS 1... Power supply fish, 2... Radiation conductor, 3... Grounding conductor, 4... Short circuit board, 9... Printed board, 13... Slit, 14... Resistor, 15... ...Slit, 16
...Disk. Agent Patent Attorney Ishi 1) Chief 7V Ward Ward ■To Figure 25 Figure 26 Procedural Amendment (Voluntary) August 5, 1988 Patent No. 4148859 No. 2 of 1988, Name of Invention Flat Antenna 3.1! 1.Relationship with the Case of Person Who Makes Corrections Patent Applicant Address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Co., Ltd. Representative Toshio Miyoshi 3 Agent postal code 530 5. Date of amendment order 6. Number of claims increased by amendment None [11 The scope of claims in the specification of the present application is as follows Correct it like this. (1) A flat plate antenna consisting of a radiating conductor with a feeding point at a predetermined point, a grounding conductor placed parallel to this radiating conductor, and a shorting plate connecting a part of one end surface of the radiating conductor to the grounding conductor. In, ``1 body dimension 5 (monthly thing ii (living Buddha, - Mu l - ta (Shoku funeral 1 ∆ distance ∆ 2 each ∆ 2 fixed stems), reactance on the short circuit board above. (2) The flat plate antenna according to claim 1, wherein the width of the shorting plate is changed. (3) The shorting plate and the radiation conductor or the grounding conductor. A flat plate antenna according to claim 1, wherein a switching element is provided on the connecting surface of the antenna, and the amount of connection between the two is changed by turning on and off the switching element.
2. The flat plate antenna according to claim 1, wherein the slit is formed in the same direction as the plane of the ground conductor, and the conductor is short-circuited or opened at any position of the slit. (5) The conductor surface of the shorting plate is divided into two by a slit, and a disk with a conductor of a predetermined shape provided on the conductor surface is pivoted, and the connection area between the conductors of the shorting plate is determined by the rotating position of the disk. 2. The flat plate antenna according to claim 1, wherein the antenna is changed. (6) Consisting of a radiating conductor with a feeding point at a predetermined point, a grounding conductor placed parallel to this radiating conductor, and a shorting plate connecting a part of one end surface of the radiating conductor to the grounding conductor, it is short-circuited. A flat plate antenna that consists of a plate that is separate from the grounding conductor and radiation conductor. (7) The flat plate antenna according to claim 1, wherein the shorting plate is made of a printed board. ” [2] “Results obtained” on page 7, line 15 of the same page was changed to “
Results are being obtained. ” he corrected. ``3'' ``Formed by etching'' in the 15th and 16th lines of page 7 of the above is corrected to ``formed by etching''. 141 Same as above, page 12, lines 4 and 7, ``It becomes lower.'' is corrected to ``It becomes higher.'' [5] Same as above, page 13, line 11 [(Mr. -1
Correct it to ``It's going to be expensive.'' r61 Same as above, page 14, line 2 (-Insert the following sentence in line 11 of short circuit board-1 above. Keep it constant, 1 [7] Attached drawing omitted 8
Correct the diagram as shown in the attached sheet. Agent Patent Attorney Ishi 1) Chief 7I! ! Figure 8

Claims (1)

[Claims] (1) A radiating conductor having a feeding point at a predetermined point, a grounding conductor arranged parallel to this radiating conductor, and a shorting plate connecting a part of one end surface of the radiating conductor to the grounding conductor. A flat plate antenna comprising: a reactance variable means for varying reactance on the shorting plate. (2) The flat plate antenna according to claim 1, wherein the width of the shorting plate is changed. (3) A flat plate antenna according to claim 1, wherein a switching element is provided at the connection between the shorting plate and the radiation conductor or the ground conductor, and the amount of connection between the two is changed by turning on and off the switching element. (4) A partially bridged slit on the conductor surface of the shorting plate,
2. The flat plate antenna according to claim 1, wherein the slit is formed in the same direction as the plane of the ground conductor, and the conductor is short-circuited or opened at any position of the slit. (5) Divide the conductor surface of the shorting plate into two with a slit,
A circular plate with a conductor of a predetermined shape on the conductor surface is pivoted,
2. The flat plate antenna according to claim 1, wherein the connection area between the conductors of the shorting plate is changed depending on the rotational position of the disk. (6) Consisting of a radiating conductor with a feeding point at a predetermined point, a grounding conductor placed parallel to this radiating conductor, and a shorting plate connecting a part of one end surface of the radiating conductor to the grounding conductor, it is short-circuited. A flat plate antenna that consists of a plate that is separate from the grounding conductor and radiation conductor. (7) The flat plate antenna according to claim 1, wherein the shorting plate is made of a printed board.