JPH04157908A - Plate antenna - Google Patents

Abstract

PURPOSE:To facilitate fine-adjustment of the resonance frequency and the impedance matching by forming a notch part prolonged from a ridge into between a ground part and a feeder to a conductive element formed through parting the ground part and the feeder with each other. CONSTITUTION:A copper foil 1Oa is provided to one surface of a PCB board 10b in a plate element 10, a ground part 12 and a feeder 13 are formed to one end, and a notch 14 is formed between the ground part 12 and the feeder 13. The feeder 13 is provided with a connecting line 18 whose one end is connected to an RF input section in a receiver 11 and whose other end is connected to the copper foil 10a of the board l0b. Three short-circuit wires 15-17 or their other ends are connected to the copper foil 10a in the ground pattern or the case 11a containing a reception circuit of the receiver 11 of the ground part 12. The impedance of an inverse-F antenna is matched by adjusting the distance between ground point and a feeding point. The impedance is easily matched by having only to adjust the length of one end 14a of the notch 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a plate-shaped inverted F used for, for example, a portable radio.
Regarding antennas.

[Prior Art] Conventionally, a plate-shaped inverted F antenna (PIF) having a configuration as shown in FIG. 9 has been used as a receiving (or transmitting) antenna.
A: Planner Invered F
Antenna) has been proposed. This figure is an external perspective view of a conventionally proposed plate-shaped inverted F antenna.

The illustrated plate-shaped inverted F antenna l includes a grounding plate 2 and this grounding plate 2.
A plate element 4 arranged parallel to the plate element 4, a shorting bin (grounding part) 3 installed between the plate element 4 and the grounding plate 2, and a feeder line 5 electrically connected to the plate element 4. It is prepared.

The human power impedance of the plate-shaped inverted F antenna 1 having such a configuration is obtained by connecting in parallel the actance of the terminal short-circuited two parallel wires consisting of the feed line 5 and the short-circuit bottle 3, and the line impedance of the plate-shaped element 4 portion. becomes. Therefore, impedance matching can be performed by adjusting the distance S between the short-circuit bin 3 and the feeder line 5. In addition, the resonant frequency is
It is closely related to the parameters of the length β5 width W of the plate element 4, the antenna height which is the distance between the plate element 4 and the grounding plate 2, and the shorting pin width d.

An antenna with such a configuration can be made smaller than a rod-type antenna, and since it can be configured almost flat, it can even be placed inside the case of a portable radio device, etc. It has the advantage of being.

[Problems to be Solved by the Invention] By the way, the resonant frequency of the above-mentioned antenna easily changes depending on the above-mentioned parameters and external circuits to be incorporated, so it is necessary to make fine adjustments when the assembly is completed. . Similarly, when trying to match impedance, the distance S between the shorting bin 3 and the feeder line 5 is
must be adjusted. However, the above configuration has a fatal drawback in that such fine adjustments cannot be made.

Furthermore, in order to achieve impedance matching, the distance between the feeder line 5 and the shorting bin 3 must be increased or decreased.
The problem that increasing or decreasing this distance would significantly restrict the design of electronic equipment in which this antenna is incorporated also remained unresolved.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a plate-shaped antenna in which fine adjustment of the resonance frequency and in-begence matching can be easily performed using the principle of the plate-shaped inverted F antenna.

[Means for Solving the Problems] The configuration of the present invention for achieving the above object includes: a conductive plate-like element in which a grounding part and a power feeding part are formed spaced apart from each other; In the plate antenna provided with opposing ground planes, the plate element is characterized in that a notch extending from an edge between the ground plane and the power feeding unit is formed. .

[Function] The function of the present invention having the above configuration is that the distance between the power feeding part and the grounding part is increased by changing the length of the cutout extending between the grounding part and the power feeding part. Change.

This change facilitates fine tuning of the resonance frequency and in-begence matching.

[Example] Hereinafter, the present invention will be explained with reference to the drawings.

Fig. 1 is a perspective view showing a planar inverted F antenna in which a plate element as an embodiment of the present invention is mounted on a receiver, and Fig. 2 (A) and (B) are similar to Fig. 1. FIG. 2 is a top view and a sectional view taken along line A-A of the plate-like element shown in FIG.

In FIG. 1, reference numeral 10 is a plate-shaped element forming the main part of the plate-shaped inverted F antenna, and reference numeral 11 is a receiver that receives and processes a signal input from the plate-shaped element IO. In this example,
The illustrated upper surface of the housing 11a of the receiver 11 is the plate-shaped element 1.
It has a function as a ground plane facing 0, that is, a function equivalent to that of the ground plate 2 shown in FIG.

Details of the plate-like element 10 are shown in FIG. 2(A).

It is as shown in (B). As shown in the same figure, the plate-like element 10 is formed by extending a copper foil 10a on one surface of a plate-like PCB board 10b, and a grounding part 12 and a power supply part 13 are provided near one end of the copper foil 10a. Furthermore, a notch 14 is formed between the grounding portion 12 and the power feeding portion 13.

The power supply section 13 has one end electrically connected to an RF input section (not shown) in the receiver 11, and the other end connected to the PCB board 1.
Connecting wires 18 each electrically connected to the copper foil 10a of 0b
It is equipped with the following.

The grounding part 12 has one end of three short-circuit wires 15 to 17 connected to a housing 11a housing a receiving circuit (not shown) of the receiver 11, etc., or a grounding pattern of the internal circuit of the receiver, and the other end thereof. The portions are electrically connected to the copper foil 10a of the PCB board 10b by solder or the like.

The notch 14 formed between the power feeding part 13 and the grounding part 12 has a substantially L-shape when viewed from above, and is formed by cutting out only the copper foil 10a. One end 14a of this notch 14 extends to the left in the figure from between the power supply section 13 and the grounding section 12, and the other end 14b is located at a distance from the grounding section 12 consisting of three short-circuit wires 15 to 17. It is formed parallel to , and its end is formed to reach the end of the copper foil 10a.

In the embodiments shown in FIGS. 1 and 2, the copper foil 10a is formed on the opposite side of the PCB board 10b to the housing 11a.
It may be formed on the side facing the.

The functions and effects of a plate-shaped inverted F antenna using a plate-shaped element having the above-described configuration will be explained with reference to FIG. 3 as well.

As described above, impedance matching of the plate-shaped inverted F antenna is performed by adjusting the distance between the ground point and the feeding point. Therefore, when the notch 14 exists between the power feeding part 13 and the grounding part 12 as shown in FIG.
This is the distance indicated by B in the figure, which detours around the one end 14a. That is, in this embodiment, impedance matching can be easily performed by simply adjusting the length of one end 14a of the notch 14. For example, assume that the end portion of the notch 14 is formed up to a portion indicated by the reference numeral 14c in FIG. When performing impedance matching in this state,
Furthermore, one end portion 14a is gradually extended and cut away in the left direction in the figure. Fine adjustment of impedance can be easily performed by such a simple operation.

Furthermore, in conventional antennas of this type, changing the distance between the feed line and the short-circuit bin means changing the formation position of the feed line and the short-circuit bin, which allows the antenna to be incorporated. Although there was a problem that significantly restricted the design of electronic equipment, in this embodiment, the grounding point and the feeding point can be formed at a constant position regardless of the impedance value. without having to change to a different dimension value,
The degree of freedom in design can be improved.

Furthermore, the housing 11 of the receiver 11. Since a is used in place of the above-mentioned ground plate 2 (shown in FIG. 9),
The plate element (PCB board) 10 can be placed above or inside the upper surface of the housing 11a. Therefore, it is possible to fully meet the demand for miniaturization.

Furthermore, in the embodiments shown in FIGS. 1 to 3, the grounding portion 1
It is also possible to change the parameters indicated by d in FIG. 9 by increasing the number of shorting wires 15 to 17 in 2 and forming them side by side, and cutting them in order from the edgemost wire.

It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

FIG. 4 is a perspective view of a plate-like element as another embodiment, and FIG.
The figure is an explanatory view showing the process of forming the notch shown in FIG. 4.

The plate element 28 shown in FIG. 4 is made of a single metal plate 28c, a part of which is cut out to form a notch 26 as shown in the figure, and this bent piece is It is bent downward in the figure to form a grounding point 28a and a power feeding point 28b.

That is, by cutting the plate-like element portions shown by solid lines 19, 20, and 27 in FIG. Feeding points 28b are respectively formed.

In this case, if one end 26a of the notch 26 is extended and cut as shown by the dotted line 26d, the length C changes and impedance matching can be achieved in the same manner as described above. A plate-shaped inverted F using a plate-shaped element with such a configuration.
Even in the case of an antenna, it is possible to obtain the same effects as in the above embodiment, and it is also possible to provide an antenna that is cheaper than the one in which copper foil is formed on the above-mentioned pCB substrate.

Furthermore, by forming the grounding point 28a into a set of a plurality of parallel strip-shaped plate pieces (comb-shaped) and cutting the plate pieces in order from the edgemost one, the parameter shown by d in FIG. 9 can be obtained. It is also possible to change.

FIG. 6 is a perspective view showing a plate-like element as yet another embodiment, and FIG. 7 is a partially enlarged detailed view thereof. In addition, from FIG. 6 onwards, the same reference numerals are given to the same parts as those explained in the above embodiment, and detailed explanation thereof will be omitted.

The plate-like element 23 shown in the same figure is the copper foil 10 of the PCB board 10.
A notch 24 having a substantially L-shape similar to the above-mentioned one is formed on the top a, but the difference from the above notch is that one end 24a of the notch 24 shown in the same figure is in the shape of an elongated hole. Notch 2
4b and 24c are formed at regular intervals so as to sandwich the cutting lines 24d and 24e.

In the case of such a notch 24, the cutting lines 24d, 24
Cut out part c and insert the other end 24f and the elongated hole-shaped notch 2.
By making 4b and 24c continuous notches, the length of one end 24a changes by a constant value. This makes it possible to obtain the same effects as in the previous embodiment.

FIG. 8 is a top view showing a modified example of the plate-like element.

The notch 25 formed in the plate-like element 10 shown in the figure is different from the notch shown in each of the embodiments described above, and has a substantially downward U-shape. Notch 25 shaped like this
If so, not only can the same effects as in the embodiment described above be obtained, but also the distance between the grounding section and the power feeding section can be set even larger.

As detailed above, the notch may be any shape as long as it can adjust the distance between the grounding part and the power feeding part, and is not limited to the shape shown in each of the above embodiments. [Effects of the Invention] As described in detail above. According to the present invention, it is possible to provide a plate-shaped inverted F antenna that allows fine adjustment of resonance frequency and in-begence matching to be easily performed.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a state in which a plate-shaped inverted F antenna is mounted on a receiver as an example, and Figs. 2 (A) and (B)
1 is a top view of the plate-shaped inverted F antenna, and a sectional view taken along line A-A. FIG. 3 is an explanatory diagram of the action of the notch formed in the plate-shaped element. FIG. 4 is another embodiment. FIG. 5 is an explanatory view showing the step of forming the notch shown in FIG. 4, FIG. 6 is a perspective view showing a plate-like element as another embodiment, and FIG. The figure is a partially enlarged detailed view, FIG. 8 is a top view showing a modified example of the plate-like element, and FIG. 9 is an external perspective view of a conventionally proposed plate-like inverted F antenna. lO... Plate element, 12... Grounding part, 13... Power feeding part, 24... Notch part. 0 ku ku mai ku ■ derivation = 46- ku size to

Claims (1)

[Claims] 1. In a plate-shaped antenna that is provided with a conductive plate-shaped element in which a grounding part and a feeding part are formed spaced apart from each other, and a ground plane facing this plate-shaped element, the plate-shaped element has a , a plate antenna characterized in that a notch is formed extending from the edge between the grounding part and the power feeding part.