JP2000269728A - Plate-shaped inverted F antenna - Google Patents

Abstract

(57) [Problem] To easily tune a planar inverted-F antenna as a planar antenna suitable for use in a relay amplifier for indoor installation and the like. SOLUTION: One of a ground conductor plate 1 and a radiation conductor plate 2 is provided with a tuning element 4 (metallic) capable of adjusting a distance h between the conductor plate and an opposite conductor plate. Also in the two-resonance type, the tuning elements 4A and 4B are provided on the upper and lower radiation conductor plates 2 and the ground conductor plate 21, respectively. Tuning elements 4, 4
The tuning frequency is adjusted and determined according to the arrangement positions of A and 4B and the size of the distance h from the opposing conductor plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna used for a relay amplifier for indoor installation, and more particularly to a planar inverted-F antenna.

[0002]

2. Description of the Related Art An indoor relay amplifier installed in a place having a low electric field strength level from a base station uses an externally connected linear antenna such as a half-wavelength dipole antenna or the like, depending on external factors. Some use built-in antennas that are not easily damaged and do not impair the aesthetics of the room. The built-in antenna generally uses a low-profile flat antenna. The planar antenna is folded with an inverted-F-shaped radiating conductor plate 2 (W × L) having one side connected to the ground conductor plate 1 along the position of the point P ₁ as shown in FIG. 2 for impedance matching. any distance r planar inverted-F antenna that is offset feed from coaxial feed line 3 to the radiating conductor plate 2 at a point away from the position P ₁ and is widely used. In the plane A antenna, when no dielectric material is inserted in the gap between the ground conductor plate 1 and the radiation conductor plate 2, the following equation is satisfied.

H + L ≒ (λ / 4) where λ = (C / f) C: 3.0 × 10 ⁸ m / s f at the speed of light f: Antenna resonance frequency H: Distance between conductor plates 1 and 2 (high Sa)

[0003]

However, actually, when a spacer or the like is arranged between the ground conductor plate and the radiation conductor plate to fix the antenna, it is the same as the fact that a dielectric material is partially inserted. , A slight deviation from the resonance frequency of the above equation occurs. Further, in the actual use state, the antenna is not exposed to the outside of the wireless device, and is covered with a case made of a resin material or a plastic material. This is because the wavelength shortening effect due to the presence of a material having a relative permittivity of 1 or more near the planar antenna acts, and the electrical antenna length appears to be longer than the physical antenna length. At this time, the amount of change in the frequency greatly varies depending on the material of the case that covers the antenna, the thickness of the case, and the distance between the case and the antenna.

Further, in a relay amplifier for a cellular phone or the like,
Since two frequencies of the uplink and the downlink are used, two antenna elements (radiation conductor plates in the case of a plate-shaped inverted-F type antenna) that resonate at each frequency are required, and two radiation conductors are required to make the antenna small. A two-frequency resonant inverted-F antenna in which plates are stacked in two stages is used (the ground conductor side of the two-stage radiating conductor plate is referred to as a resonance conductor plate, and the other is referred to as a radiating conductor plate. At this time, the resonance conductor plate is tuned to the lower frequency of the two frequencies, and the radiation conductor plate is tuned to the higher frequency. In this shape, if the length of one of the conductor plates is adjusted to the desired frequency, the other frequency is also affected. Therefore, considerable time and labor are required to obtain the optimum conditions.
As described above, when manufacturing a planar antenna, it is necessary to experimentally adjust the antenna length depending on various external conditions, and there is a problem that much time and labor are required for the adjustment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conventional technique without changing the antenna length even when external conditions change.
An object of the present invention is to provide a plate-shaped inverted-F antenna that can be tuned to a desired resonance frequency. It is a further object of the present invention to provide a plate-shaped inverted-F antenna that enables such simple tuning even for two-frequency resonance.

[0006]

SUMMARY OF THE INVENTION The present invention is a plate-shaped inverted-F antenna comprising a radiation conductor plate and a ground conductor plate, wherein at least one of the radiation conductor plate and the ground conductor plate has:
A plate-shaped inverted-F antenna provided with an antenna tuning element is disclosed.

Further, the present invention relates to a two-frequency resonance plate-shaped inverted F-type radio antenna comprising a radiation conductor plate, a resonance conductor plate and a ground conductor plate, wherein at least one of the radiation conductor plate and the ground conductor plate is provided. On the other hand, a plate-shaped inverted-F antenna provided with an antenna tuning element is disclosed.

Further, according to the present invention, the tuning element is a screw-type element having an external diameter of an external thread, which is inserted into a screw hole provided at a predetermined position of the conductor plate to be installed, and is provided between the opposing conductor plate and the tip of the tuning element. Disclosed is a plate-shaped inverted-F antenna that adjusts the distance to adjust the tuning.

Further, the present invention discloses a plate-shaped inverted-F antenna having one or a plurality of tuning elements.

Further, the present invention discloses a plate-shaped inverted-F antenna in which a flat plate having a larger cross-sectional area than the tip is provided at the tip of the tuning element.

Further, the present invention discloses a relay amplifier for indoor installation equipped with a plate-shaped inverted-F antenna.

According to the invention, the tuning element is brought close to the grounding conductor plate from above the radiation conductor plate to partially change the capacitance between the grounding conductor plate and the tuning element, or the tuning element is arranged below the grounding conductor plate. Then, the tuning element is brought close to the radiation conductor plate, and the capacitance between the radiation conductor plate and the tuning element is partially varied, thereby performing tuning at a desired resonance frequency.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the appearance of a planar inverted F-shaped planar antenna provided with a tuning element, and FIG. 3 is a side view at that time. The bolt-shaped element 4 is a tuning element that is a feature of the present invention, and has a structure in which the distance h between the element tip and the radiation conductor plate 2 can be adjusted from under the ground conductor plate 1.
However, the adjustment range is a range less than the height H within a range that does not contact the radiation conductor plate 1.

The tuning element 4 is a bolt-shaped conductor element (for example, a metal element) having a male screw outer diameter portion 10 and a gripping head 11. Further, the ground conductor plate 1 was provided with a hole 12 having a female screw inner diameter into which the tuning element 4 can be screwed, at a selected position. Then, by turning the head 11, the tuning element 4 is screwed into the hole 12. A desired resonance frequency is obtained by adjusting the distance h between the tip of the element 4 and the radiation conductor plate 2.

In the present embodiment, the width W of the radiation conductor plate 1 is
Length L and height H are, for example, 100 mm and 79 m, respectively.
m, a 10 mm, is offset feed from coaxial feed line 3 at a point at a distance r = 31 mm from the position P ₁ folded the radiating conductor plate 1. FIG. 4 shows the reflection characteristics of the antenna when there is no tuning element 4 of the present invention as a reference. At this time, the antenna resonance frequency f ₀ is 842 MHz.
It is.

On the other hand, the tuning element 4 of the present invention functions as a matching circuit for the radiating conductor plate 2 at a high frequency. As an embodiment, FIG. 5 shows the reflection characteristics when a location on the distal end side of the radiation conductor plate 1 is selected and an element 4 having a circular cross section with a diameter of 10 mm is set to a gap h = 2 mm immediately below. The dotted line shows the characteristic itself in FIG. 4, and the solid line shows the characteristic when the tuning element 4 is provided.
Antenna resonant frequency f ₀ at this time was 783MHz, resonant frequency f ₀ as compared to the absence of the tuning element 4
Varies by 59 MHz. FIG. 6 is a graph showing the amount of change in the resonance frequency when the gap h is changed at this time. Similarly, the antenna of FIG. 7 when the element 4 having a circular cross section with a diameter of 10 mm is set to a gap h = 2 mm immediately below a position at a distance s = 15 mm from the short-circuit portion P ₁ of the radiation conductor plate 1. FIG. 8 shows the reflection characteristics. At this time, the antenna resonance frequency f ₀ is 854 MHz, and the tuning element 4
It changes 12 MHz higher than when there is no. FIG. 9 is a graph showing the amount of change in the resonance frequency when the gap h is changed.

From these facts, it can be seen that when the tuning element 4 is arranged and the gap h is reduced, the frequency change is large, and conversely, when the gap h is large, the change is small.

In this embodiment, the tuning element 4 is arranged in the direction of the end opposite to the coaxial feeder line, because the electric field of the radiation conductor plate is the strongest, so that it is directly below the center of the radiation conductor plate, or This is because the effect is greater than the end of the coaxial feed point.
Further, the place where the sign of the resonance frequency f ₀ changes in the present embodiment is near the distance s = 30 mm from the short-circuited portion P ₁ . That is, when s = 30 mm or more, the resonance frequency f ₀
Is lower, and when s = 30 mm or less, the resonance frequency f ₀ tends to increase. Further, in this embodiment, the tuning element 4 is made of a metal screw because it is easy to adjust. However, any element may be used as long as it is a conductor. Examples of the cross-sectional shape may be other than circular.

As another embodiment, there is an example in which a flat plate 5 having a large sectional area is provided at the tip of the tuning element as shown in FIG. Providing the flat plate 5 has an advantage that the variable amount can be increased. In this case, the flat plate 5 is fixed to the tip of the element with, for example, an adhesive after the hole is inserted. The tuning element 4
Is arranged, the amount of change in the resonance frequency can be increased, and adjustment with a higher degree of freedom can be performed.

FIG. 11 shows an example in which the tuning element 4 is attached to the radiation conductor plate 2, unlike the examples shown in FIGS. FIG. 12 shows a side view. This embodiment is an example in which a hole 13 is provided at a predetermined position of the radiation conductor plate 2 and the tuning element 4 is screwed into the hole 13 and inserted. Although the arrangement of the coaxial feeder line 3 and a diagram as a perspective view are different from those in FIG. 1, they are the same and do not change.

With the configuration shown in FIG. 11, the tuning element 4 approaches the grounding conductor plate 1 from above the radiation conductor plate 2, and the capacitance between the radiation conductor plate 2 and the tuning element 1 is varied, so that a desired value is obtained. Tune at resonance frequency. The element 4 has a structure that can be adjusted from above the radiation conductor plate 2, and is made variable within a range less than the height H within a range not in contact with the ground conductor plate 1.

In this embodiment, for example, the width W of the radiation conductor plate 2 is 100 mm, the length L is 80 mm, and the height H is 10 mm.
a mm, is offset feed from coaxial feed line 3 at a point at a distance r = 76 mm from the position P ₁ folded the radiating conductor plate 2. FIG. 12 is a side view at that time.

FIG. 13 shows the reflection characteristics of the antenna of the present embodiment when there is no tuning element 4 for reference. At this time, the antenna resonance frequency f ₀ is 905.25 MHz.

On the other hand, since the tuning element 4 of the present invention functions as a matching circuit for the radiation conductor plate 2 at a high frequency, the resonance frequency differs depending on the location. FIG. 14 shows the reflection characteristics of the antenna when an element 4 having a circular section having a diameter of 3 mm and a gap h = 1 mm is provided immediately below the distal end side of the radiation conductor plate 2 as an embodiment. The antenna resonance frequency f at this time
₀ is 886.75 MHz, and the resonance frequency f ₀ changes by 18.5 MHz lower than when the tuning element 4 is not provided. Similarly, just below the distance s = 5 mm away from the short-circuit portion P ₁ of the radiating conductor plate 2, when the element 4 having a circular cross section with a diameter 3mm in the gap h = 1 mm (Fig. 15)
FIG. 16 shows the reflection characteristics of the antenna of FIG. At this time, the antenna resonance frequency f ₀ is 911.25 MHz, and f ₀ changes by 6 MHz higher than when the tuning element 4 is not provided.

Since the amount of change in the frequency changes by further changing the gap h between the tuning element and the radiation conductor plate, it is possible to tune to a desired frequency. FIG. 17 shows the relationship between h and the amount of change in the resonance frequency when a screw having a circular cross section with a diameter of 3 mm is arranged immediately below the tip of the radiation conductor plate 2. From these facts, it can be seen that when the tuning element 4 is arranged and the gap h is reduced, the amount of frequency change is large, and conversely, when the gap h is large, the change is small.

In this embodiment, the tuning element 4 is arranged in the direction of the end opposite to the coaxial feeder line, because the electric field of the radiating conductor plate is the strongest. This is because the effect is greater than the end of the coaxial feed point. However, the arrangement position of the element 4 can be variously set.

In a relay amplifier of a cellular phone or the like, since two frequencies of an uplink and a downlink are used, two antenna elements (plate-like inverted F) that resonate at respective frequencies are used.
In order to make the antenna small, two radiation conductor plates are stacked in two stages.
An inverted-F antenna with frequency resonance is used. The ground conductor side of the two-tiered radiation conductor plate is referred to as a resonance conductor plate, and the other is referred to as a radiation conductor plate. For example, the resonance same conductor plate 21
Are tuned to the lower frequency of the two frequencies, and the radiation conductor plate 22 is tuned to the higher frequency.

FIG. 32 shows a configuration example of the relay amplification means including such a relay amplifier. The relay amplification unit 100 is connected to the outdoor antenna 101 and includes a duplexer 102, a downlink relay amplifier 103, a band-pass filter 104, a downlink indoor antenna 105, an uplink indoor antenna 108, a band-pass filter 107, and an uplink relay amplifier 106. . Here, the antennas 105 and 108 are configured as two-frequency resonant plate-shaped inverted-F antennas.

FIG. 18 shows an embodiment in which the present invention is applied to such an inverted-F type antenna having two-frequency resonance. On the ground conductor 1,
The radiation conductor plates 21 and 22 which are two-tiered are provided in an inverted F-shape. The radiation conductor plate 21 becomes a resonance conductor plate. The tuning element 4 is attached to the ground conductor plate 1 as in the example of FIG.
The tuning element 4 is brought close to a part of the resonance conductor plate 21 from under the grounding conductor plate 1, and the capacitance between the resonance conductor plate 21 and the tuning element 4 is partially changed, so that the desired resonance frequency can be obtained. Synchronize. The tuning element 4 has a structure that can be adjusted from below the grounding conductor plate 1, and achieves variability within a range less than the height H <b> 1 in a range not in contact with the resonance conductor plate 21.

In the present embodiment, for example, the resonance conductor plate 21
And the width W of the radiation conductor plate 22 = 100 mm, the length L1 of the resonance conductor plate 21 = 85 mm, and the length L2 of the radiation conductor plate 22
= 74 mm, height H1 = 6 mm the resonant frequency 21, a H2 = 4 mm of the radiating conductor plate 22, coaxial feeder 3 at a point at a distance r = 43 mm from the position P ₁ folded the radiation conductor plate 22 More offset feeding. FIG.
FIG. 9 is a side view at that time.

FIG. 20 shows, for reference, the reflection characteristics of the antenna of the present embodiment when there is no tuning element 4. At this time, the antenna resonance frequencies f ₀₁ and f ₀₂ are 822.5 MHz.
And 960.0 MHz.

On the other hand, since the tuning element 4 of the present invention functions as a matching circuit for the resonance conductor plate 21 at a high frequency, the resonance frequency differs depending on the location. As an embodiment, FIG. 21 shows the reflection characteristics of the antenna when a screw having a circular cross section with a diameter of 3 mm and a gap h1 = 1 mm is provided immediately below the tip of the resonance conductor plate 21. The antenna resonance frequencies f ₀₁ and f ₀₂ at this time are 816.25 MHz and 960.0 M
A Hz, compared to vary the resonance frequency f ₀₁ only 6.25MHz low as when there is no tuning element 4. Similarly, when a metal screw element 4 having a circular cross section of 3 mm in diameter is arranged at a gap h1 = 1 mm immediately below a position at a distance s = 5 mm from the short-circuited portion between the resonance conductor plate and 21 (FIG. 22). FIG. 23 shows the reflection characteristics of the antenna. At this time, the antenna resonance frequencies f ₀₁ and f ₀₂ are 823.75 MHz and 96
F ₀₁ from the time when there is no tuning element 4
Only 1.25 MHz changes higher.

Since the amount of change of the frequency changes by changing the gap h1 between the tuning element and the resonance conductor plate, it is possible to tune to a desired frequency.

Next, a third embodiment of the present invention will be described. FIG. 24 shows that the tuning element 4 is brought close to a part of the resonance conductor plate from above the radiation conductor plate 22, and the resonance conductor plate 2 and the tuning element 4
By partially changing the distance (capacity) between
FIG. 3 is a side view of a planar antenna characterized in that tuning is performed at a desired resonance frequency. The tuning element 4 is a radiation conductor plate 22
Can be adjusted from above, and can be made variable within a range of less than the height H2 within a range not in contact with the resonance conductor plate 21. In the present embodiment, for example, the width W of the resonance conductor plate 21 and the radiation conductor plate 22 and the length L of the resonance conductor plate 21
1. The length L2 of the radiation conductor plate 22, the height H1 of the resonance conductor plate 21, the H2 of the radiation conductor plate 22, and the offset power supply position are all the same as in the second embodiment. At the tip of the radiation conductor plate 22, a screw having a circular cross section of 3 mm in diameter is inserted into the gap h.
FIG. 25 shows the reflection characteristics of the antenna when 2 = 1 mm. The antenna resonance frequencies f ₀₁ and f ₀₂ at this time are 82
2.5 MHz and 947.5 MHz, compared to the case where the tuning element 4 is not provided, only the resonance frequency f ₀₂ is 12.5 M
Hz lower. Similarly, just below the position at a distance s = 5 mm from the short-circuited portion of the radiation conductor plate 22, a diameter of 3
mm screw gap 4 having a circular cross section of 1 mm
FIG. 2 shows the reflection characteristics of the antenna when the antenna is arranged in FIG.
FIG. At this time, the antenna resonance frequencies f ₀₁ and f ₀₂ are 822.5 MHz and 962.5 MHz, and only f ₀₂ changes by 2.5 MHz higher than when there is no tuning element 4. As in the second embodiment, the amount of change in the frequency changes by changing the gap h2 between the tip of the tuning element 4 and the resonance conductor plate 21, so that the desired frequency can be tuned.

FIG. 28 shows a fourth embodiment in which the second and third embodiments are simultaneously combined. The tuning element 4 of the radiation conductor plate 22 is 4 A, and the ground conductor plate 21
The tuning element 4 was designated as 4B. FIG. 29 shows the antenna characteristics. In the present embodiment, for example, the width W of the resonance conductor plate 21 and the radiation conductor plate 22, the length L1 of the resonance conductor plate 21, the length L2 of the radiation conductor plate 22, the resonance conductor plate 21
The height H1, the height H2 of the radiation conductor plate 22, and the offset feeding position are all the same as those of the second embodiment. The tuning element 4B has a diameter of 3 m immediately below the tip of the resonance conductor plate 21.
A screw element having a circular cross section of m was set to a gap h1 = 1 mm, and a tuning element 4A was a screw having a circular section having a diameter of 3 mm at the tip of the radiation conductor plate 22 was set to a gap h2 = 1 mm. At this time, the antenna resonance frequencies f ₀₁ and f ₀₂ are 816.25 MHz and 947.5 MHz, f ₀₁ changes 6.25 MHz lower than when there is no tuning element, and f ₀₂ is 12.5 MHz.
z lower. This is the same change amount as when individually adjusted by the tuning elements. The tuning element 4B has a screw having a circular cross section with a diameter of 3 mm just below the tip of the resonance conductor plate 21 with a gap h1 = 1 mm. FIG. 31 shows the reflection characteristics of the antenna when an element screw element having a circular cross section with a diameter of 3 mm is arranged at a gap h2 = 1 mm immediately below the distant position (FIG. 30). The antenna resonance frequency f at this time
₀₁ and f ₀₂ are 816.25 MHz and 962.5 MHz
And f ₀₁ is 6.25 MH since there is no tuning element.
It changes z lower and f ₀₂ changes 2.5 MHz higher. This is also the same change amount as when individually adjusted by the tuning element.
This indicates that the two frequencies can be tuned separately without affecting each other.

There may be an example in which a tuning element is provided on the resonance conductor plate.

[0037]

As described above, the use of the tuning element of the present invention has the effect of tuning to a desired resonance frequency without changing the antenna element length even when external conditions change. Yes, antenna design time can be significantly shorted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a planar inverted-F antenna which is a planar antenna according to the present invention.

FIG. 2 is a perspective view showing an appearance of a conventional planar antenna.

FIG. 3 is a side view when a tuning element according to the present invention is arranged.

FIG. 4 shows the reflection characteristics of a plate-shaped inverted-F antenna when there is no tuning element 4;

FIG. 5 is a graph showing reflection characteristics of an antenna depending on whether or not a tuning element 4 is installed.

FIG. 6 is a graph showing the relationship between the gap h and the amount of change in the resonance frequency at that time.

FIG. 7 is a perspective view of the tuning element 4 installed at another position.

FIG. 8 is a diagram showing reflection characteristics of the antenna depending on whether or not the element 4 is installed at that time.

FIG. 9 is a graph showing the relationship between the gap h and the amount of change in the resonance frequency at that time.

FIG. 10 shows another embodiment.

FIG. 11 is a perspective view showing the appearance of another plate-shaped inverted-F antenna of the present invention.

FIG. 12 is an external side view of a plate-shaped inverted-F antenna according to the present invention.

FIG. 13 shows the reflection characteristics of the inverted inverted-F plate antenna when there is no tuning element 4;

FIG. 14 shows the reflection characteristics of a plate-shaped inverted F antenna depending on whether or not a tuning element 4 is provided.

FIG. 15 is a side view of the plate-shaped inverted-F antenna when the tuning element 4 is arranged at another position.

FIG. 16 shows the reflection characteristics of a plate-shaped inverted F antenna depending on whether or not a tuning element 4 is provided.

FIG. 17 is a graph showing the amount of change in the plate-like inverted F antenna resonance frequency when the gap h is changed.

FIG. 18 is a perspective view showing the appearance of a two-frequency resonant plate-shaped inverted-F antenna of the present invention.

FIG. 19 is a side view showing the appearance of a two-frequency resonant plate-shaped inverted-F antenna of the present invention.

FIG. 20 shows reflection characteristics of the dual-frequency resonant plate-like inverted F antenna when there is no tuning element 4;

FIG. 21 shows the reflection characteristics of a two-frequency resonant plate-shaped inverted-F antenna depending on whether or not a tuning element 4 is installed.

FIG. 22 shows a side view of another two-frequency resonant plate-shaped inverted-F antenna of the present invention.

FIG. 23 shows reflection characteristics of the dual-frequency resonant plate-shaped inverted-F antenna depending on the presence or absence of the tuning element 4 at that time.

FIG. 24 is a side view showing the appearance of another two-frequency resonant plate-shaped inverted-F antenna of the present invention.

FIG. 25 shows reflection characteristics of the dual-frequency resonant plate-shaped inverted-F antenna depending on the presence or absence of the tuning element 4 at that time.

FIG. 26 shows a side view of a two-frequency resonant plate-shaped inverted-F antenna of the present invention.

FIG. 27 shows reflection characteristics of the dual-frequency resonant plate-shaped inverted-F antenna depending on the presence or absence of the tuning element 4 at that time.

FIG. 28 shows a side view of a two-frequency resonant plate-shaped inverted-F antenna provided with tuning elements 4A and 4B of the present invention.

FIG. 29 shows reflection characteristics of the dual-frequency resonant plate-shaped inverted-F antenna depending on the presence or absence of the tuning elements 4A and 4B at that time.

FIG. 30 is a side view of a two-frequency resonant plate-shaped inverted-F antenna in which tuning elements 4A and 4B of the present invention are provided at different positions.

FIG. 31 shows reflection characteristics of the dual-frequency resonant plate-shaped inverted-F antenna depending on the presence or absence of the tuning elements 4A and 4B at that time.

FIG. 32 is a diagram illustrating a configuration example of a relay amplification unit.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 ground conductor plate 2 radiation conductor plate 3 coaxial feed line 4, 4A, 4B tuning element 21 resonance conductor plate 22 radiation conductor plate W lateral width of radiation conductor plate (resonance conductor plate) L1 length of resonance conductor plate L, L2 radiation Length of the conductor plate H Height of the radiation conductor plate from the ground conductor plate H1 Height of the resonance conductor plate from the ground conductor plate H2 Height of the radiation conductor plate from the resonance conductor plate r Bending position of the radiation conductor plate H1 Gap between the resonance conductor plate and the tuning element h2 Gap between the radiation conductor plate and the tuning element s Distance from the short-circuited part of the tuning element

Claims (6)

[Claims] An inverted F-shaped antenna comprising a radiation conductor plate and a ground conductor plate, wherein at least one of the radiation conductor plate and the ground conductor plate is provided with an antenna tuning element. F type antenna. 2. A two-frequency resonance plate-shaped inverted-F wireless antenna comprising a radiation conductor plate, a resonance conductor plate, and a ground conductor plate, wherein at least one of the radiation conductor plate and the ground conductor plate has: A plate-shaped inverted-F antenna provided with an antenna tuning element. 3. The tuning element is a screw type element having an external diameter of a male screw, and is inserted into a screw hole provided at a predetermined position of a conductor plate to be installed to adjust the distance between the opposing conductor plate and the tip of the tuning element. 3. A tuning adjustment is performed by performing
Inverted F-shaped antenna. 4. The plate-shaped inverted-F antenna according to claim 1, wherein one or more tuning elements are provided. 5. The inverted F-shaped antenna according to claim 1, wherein a flat plate having a larger cross-sectional area than the tip is provided at the tip of the tuning element. 6. The plate-like inverted F according to claim 1,
A relay amplifier for indoor installation with a built-in antenna.