JPH04157906A - Plane antenna - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the antenna efficiency due to spurious radiation by providing a 2nd conductor plate between 1st and 3rd conductor plates having an opening opposite to each other at a prescribed interval and a radiation element coupled with a feeder electromagnetically provided on the 2nd conductor plate in the opening of the 1st conductor plate. CONSTITUTION:A conductor plate 22 made of a conductive metal is formed on a flexible film 20. A circular opening 24 is provided to the plate 22 and a spiral radiation element 26 is provided in the opening 24. The element 26 generates a circularly polarized wave. A flexible film 28 is provided under the film 20 at a prescribed interval, a feeder 30 is formed to the upper side, an exciting probe 32 is formed integrally to the tip and coupled with the element 26 electromagnetically. A flexible film 34 is provided under the film 28 at a prescribed interval, a conductor plate 36 is formed to the upper side and an opening 38 is formed to a position corresponding to the opening 24. Since conductor plates 22,36 are in existence above and under the feeder 30, the plates 22,36 act like ground conductors with respect to the plate 22 to form a tri-plate feeder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a planar antenna used for receiving radio waves in the microwave band, for example.

[Prior Art] Conventionally, various planar antennas have been proposed, such as those shown in FIGS. 18 and 19. In this method, a dielectric plate 12 is provided on a ground conductor plate 10 shown in FIG.
4 and a power supply line 16 connected to the power supply line 16.

[Problems to be Solved by the Invention] In such a planar antenna, high frequency power is supplied to the spiral radiating element 14 via the feed line 16, and is radiated from the spiral radiating element 14.

However, a part of the high frequency power is radiated from the feed line 16 while traveling on the feed line 16. That is, unnecessary radiation occurs. This unnecessary radiation causes deterioration of the antenna site lobe characteristics, resulting in a problem in that the antenna efficiency decreases. In theory, these problems also occur when a flat antenna is used for reception.

An object of the present invention is to provide a planar antenna that solves the problems described in -.

[Means for Solving the Problems] In order to achieve the above object, the first invention provides a first conductor plate having a first opening, a conductor plate that is spaced apart from the first conductor plate, and is substantially parallel to the first conductor plate. a second conductor plate which is disposed at the top and has a second opening at a position corresponding to the first opening; and a second conductor plate which is provided between the first and second conductor plates substantially parallel thereto and has a tip end or a second opening at a position corresponding to the first opening; a feed line extending to the vicinity and forming a triplate feed line in cooperation with the first and second conductor plates; and a radiating element provided within the first opening and electromagnetically coupled to the feed line. , a third conductive plate provided parallel to the second conductive plate on the opposite side to the first conductive plate.

The second invention is a coplanar type in which the feeding line is directly connected to the radiating element, instead of the radiating element being electromagnetically coupled to the feeding line in the first invention, and the radiating element is connected to the feeding line directly. was provided in the first opening, the first and second
It is provided between the openings.

Furthermore, in the first and second inventions, a dielectric may be provided between the first and second conductor plates, and a dielectric may be provided between the second and third conductor plates.

[Operation/Effect] According to the first and second inventions, the feed line is provided between the first conductor plate and the second conductor plate, constitutes a triplate feed line, and forms a closed circuit. Therefore, unnecessary radiation is hardly generated in the antenna radiation direction while high frequency power is being transmitted through the feed line.

In the case of a simple triplate feed line, the feed line is provided between the first conductor plate and the second conductor plate, and the radio waves from the radiating element are radiated through the first opening. In this case, the distance between the radiating element and the second conductor plate is set to be a distance suitable for forming a triplate line.

By the way, the bandwidth of an antenna is determined by the Q value as one parameter.
It is determined by the dielectric loss tangent and conductivity). Therefore, depending on the distance between the radiating element and the second conductor plate determined to configure the triplate line as described above, it is not possible to set an appropriate Q value to make the antenna broadband. becomes narrower.

However, in the first and second inventions, a second opening is provided in the second conductor plate at a position corresponding to the second radiating element, and a second opening is provided in the second conductor plate in place of the second conductor plate. A third conductor plate is provided outside the second conductor plate, and this third conductor plate functions as a conductor plate for the second radiating element. Therefore, according to the first and second inventions, the conductor plate for the radiating element;
That is, the distance between the third conductive plate and the radiating element can be arbitrarily selected, and the Q value can be set to an arbitrary value.
It is possible to configure a wideband antenna.

[Example] A first example is shown in FIGS. 1 to 3. In this embodiment, as shown in FIG. 1, a thin flexible film 2
0, and a conductive plate 22 made of, for example, a conductive metal is formed over the entire upper surface thereof. A circular opening 24 is provided in this conductor plate 22, and a second
As shown in the figure, a circular spiral radiating element 26 is provided. This spiral radiating element 26 is, for example, about 1
The line length is between 1.25 and 8 (input is the line wavelength of the center frequency of the band to be received by this planar antenna), and the line width and pitch are determined to generate good circularly polarized waves. ing.

2. Below the flexible film 20, another thin flexible film 28 is provided parallel to the flexible film 20 at a predetermined interval,
A strip-shaped power supply line 30 is formed on its upper surface.

The tip of this feed line 30 extends to the vicinity of the opening 24, and an excitation probe 32 as shown in any one of FIGS. 3(a) to 3(c) is integrally formed at this tip.

As shown in FIG. 1, this excitation probe 32 is located directly below the outer portion of the spiral radiation element 26, and has a shape that is aligned with the spiral radiation element 26.

This excitation probe 32 is electromagnetically coupled to the spiral radiation element 26.

Below the flexible film 28, another thin flexible film 34 is provided parallel to the flexible film 28 at a predetermined interval. A conductor plate 36 is formed over the entire upper surface of the film 34, and an opening 38 is formed at a position corresponding to the opening 24. Since the conductor plates 22 and 36 are located above and below the feed line 30, the conductor plates 22 and 36 function as ground conductors for the feed line 30, forming a triplate feed line. .

Beneath the flexible film 34, flexible films 40 are arranged parallel to each other at a predetermined interval, and a conductor plate 42 is formed over the entire upper surface of the flexible film 40. Since the opening 38 is formed in the conductive plate 36, the conductive plate 42 functions as a ground conductor for the spiral radiating element 26.

In the planar antenna configured in this manner, the high frequency power traveling through the feed line 30 is supplied from the excitation probe 32 to the spiral radiation element 2δ by electromagnetic coupling, thereby generating circularly polarized waves.

At this time, as described above, the feed line 30 and the conductor plate 22.3
6 constitutes a triplate feed line and forms a closed circuit, so that almost no unnecessary radiation is generated from the feed line 30 in the antenna radiation direction.

Further, as described above, since the conductor plate 42 functions as a ground conductor for the spiral radiating element 26, by appropriately selecting the interval between the conductor plate 42 and the conductor plate 36, the Q value, and it becomes possible to widen the band.

A second embodiment is shown in FIG. This embodiment is an example in which a plurality of planar antennas of the first embodiment are provided to form an array antenna. Parts equivalent to those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 5 shows a third embodiment. This embodiment has the same structure as the first embodiment except that the method of feeding power to the spiral radiating element 26 is different. Equivalent parts are given the same reference numerals and detailed explanations are omitted. In this embodiment, the spiral radiating element 26 is not located within the aperture 24, but rather within the feed line 3.
0 is provided at a position corresponding to the opening 24 in the flexible film 28, and its outer portion is directly connected to the power supply line 3G. That is, coplanar power feeding is performed. This embodiment also operates in the same way as the first embodiment.

FIG. 6 shows a fourth embodiment. This embodiment is an example in which a plurality of planar antennas of the third embodiment are provided to form an array antenna. Portions equivalent to those in the third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the first to fourth embodiments, a circular spiral radiating element 26 was used as the spiral radiating element 26, or a rectangular spiral radiating element may be used, and power was supplied to the outer part of the spiral radiating element 26. However, power may be supplied from the inner part. Also, as is clear from each country, the conductor plate 22.36 and the feed line 30 are made of film 20.34.
．． It may be provided on the upper surface of 28 or on the lower surface.

A fifth embodiment is shown in FIGS. 7 and 8. In this embodiment, the openings 24a and 38a formed in the conductor plate 22, 36 are not circular but rectangular, the radiating element 26a is not a spiral radiating element but a rectangular circularly polarized wave radiating element, and the conductor plate 4
2a is constructed in the same manner as the first embodiment, and operates in the same manner as the first embodiment. In the fifth embodiment, a rectangular circularly polarized wave element 26a is used, but a circular circularly polarized wave element may also be used.
It may also be a circular or rectangular linearly polarized radiation element. Furthermore, the same operation can be achieved by making the openings 24a and 38a circular or rectangular to correspond to the radiating element.

FIG. 9 shows a sixth embodiment. In this embodiment, the conductor plate 2
2a and 36a are not provided on the flexible film, but similarly to the third embodiment, the radiating element 26a is provided on the flexible film 28 rather than within the opening 24a, and is directly connected to the transmission line 30. 5th except for the fact that
It is constructed and operates similarly to the embodiment.

A seventh embodiment is shown in FIGS. 10 and 11. In this embodiment, like the sixth embodiment, the conductor plates 22a and 34a are not provided on the flexible film, and the openings 24.3
8 is different from the sixth embodiment in that it is circular. Also, the 6th
What differs most from the embodiment is the radiating element. That is, in this embodiment, the radiating element is constituted by two orthogonal tie ball elements 26al, 26a2, which are provided on the flexible film 28. These tie ball elements 26a1 and 26a2 are connected to a power supply line 30 also provided on the flexible film 28 via power supply lines 30a and 30b. However, in order to provide a phase difference of 90 degrees to the dipole elements 26a1 and 26a2 so as to generate a circularly polarized wave, the feed line 30b is placed at an angle of 80 degrees higher than the feed line 30a.
/4 lengthened. In addition, each dipole element 26
These widths are selected so that power is supplied to a1, 26 and a2 with equal amplitude. This embodiment also operates in the same way as the sixth embodiment.

An eighth embodiment is shown in FIGS. 12 and 13. This embodiment has the same structure as the seventh embodiment except for the configuration of the radiating element. That is, the radiating element of this embodiment consists of four tie ball elements 26bl, 26b2.26b3.26b4 arranged orthogonally to each other,
From the feed line 30 to the feed lines 30c, 30d, 30e, 3
0'', 30g, 30!1, or the feed line 30c so that each tie ball element 26b1.26b2.26b3.26b4 has a phase difference of 0 degree, 90 degree, 180 degree, 270 degree. The feed line 30f is longer than the same 30d by λ□/4, the feed line 30h is longer than the same 30g, and the feed line 30h is longer by /4. Element 26b1.2
The feed lines 30c, 30d, 30e, 30f, 30g,
A width of 30h has been selected. This embodiment also operates in the same manner as the seventh embodiment.

FIG. 14 shows a ninth embodiment. This embodiment is composed of radiating elements or cross tie ball elements 26all, 26a21, cross tie ball elements 26a11 .
The structure is similar to that of the sixth embodiment except that 26a21 is electromagnetically coupled to the feed lines 30a and 30b, and operates in the same manner.

FIG. 15 shows a tenth embodiment. This embodiment is constructed in the same manner as the sixth embodiment, except that it is composed of a radiation element or one tie-ball element 26c, and that this tie-ball element 26c functions as a linearly polarized wave element. and works similarly.

FIG. 16 shows an eleventh embodiment. This embodiment is constructed similarly to the sixth embodiment except that the radiating element is a triple tie ball element consisting of three tie ball elements 26, 26d2, 26d3 spaced 120 degrees apart. Thermal theory, each dipole element 26dl, 26d2.2
The power supply line 6d3 is configured to have a phase difference of 0 degrees, 120 degrees, and 240 degrees, and each tie ball element 2 is configured so that the power is supplied to each tie ball element with equal amplitude.
The width of the power supply line to 6dl, 26d2, or 26d3 is selected. This embodiment also operates in the same manner as the embodiment of FIG.

FIG. 17 shows a twelfth embodiment. In this embodiment, the radiating elements are three tie ball elements 26dll, 26d2], 2
The configuration differs from the 11th embodiment in that it is composed of a triple dipole consisting of 6d31 and its arrangement.The power supply to each dipole element 26d11.26d21.26d:II has a phase difference of 0 degrees, 120 degrees, and 240 degrees. The feed line 30j is 8/3 longer than 30i, and the feed line 301 is 1/3 longer than 30i, which is different from the embodiment shown in FIG. This embodiment also operates in the same manner as the embodiment of FIG.

The planar antennas shown as the fifth to twelfth embodiments also
As in the second and fourth embodiments, they can be combined to form an array antenna. If the conventional configuration is used as an array antenna, the feed line 30 will become complicated, unnecessary radiation will increase, and the antenna site roller characteristics will deteriorate significantly.
When used as a rear array antenna with the configuration of the present invention, excellent effects can be obtained. Further, in the fifth and subsequent embodiments, each conductor plate may not be provided on the flexible film, or may be provided on the flexible film as in the first and third embodiments.

In each of the above embodiments, the conductor plates are arranged at intervals, but a dielectric material may be provided between them.

[Brief explanation of the drawing]

1 is a sectional view taken along line A-A in FIG. 2, FIG. 2 is a plan view of the first embodiment of the planar antenna according to the present invention, and FIGS. Plan views of various excitation probes used in the examples, FIG. 4 is a plan view of the second example, FIG. 5 is a vertical cross-sectional view of the third example, and FIG. 6 is a plan view of the fourth example. A plan view, FIG. 7 is a sectional view taken along the line B-B in FIG. 8, FIG. 8 is a plan view of the fifth embodiment, FIG. 9 is a longitudinal sectional side view of the sixth embodiment, and FIG. is a sectional view taken along c-cm in FIG. 11, FIG. 11 is a plan view of the seventh embodiment, and FIG. 12 is a cross-sectional view of the first embodiment.
3 is a cross-sectional view taken along line D-D in FIG. 3, FIG. 13 is a plan view of the eighth embodiment, FIG. 14 is a plan view of the ninth embodiment, and FIG. 15 is a plan view of the tenth embodiment. , FIG. 16 is a plan view of the eleventh embodiment, FIG. 17 is a plan view of the twelfth embodiment, and FIG.
The figure is a plan view of a conventional planar antenna, and FIG. 19 is a sectional view of the conventional planar antenna. 22.22a...first conductor plate, 24.24a...
...first opening, 26.26a, 26al, 26a2.
26all, 26a2], 26bl, 26b2.26
b3.26b4.26c, 26dl, 26d2.2
6d3.26dll, 26d21.25d:II...
・Radiating element, 30...Feeding line, 36.36a...
...Second conductor plate, 38.38a...Second opening, 42.42a...Third conductor plate.

Claims (3)

[Claims] (1) A first conductor plate having a first opening, and a second conductor plate arranged substantially parallel to the first conductor plate with a distance therebetween and having a second opening at a position corresponding to the first opening. A tri-plate power supply line is provided between a conductive plate and a first and second conductive plate, which are substantially parallel to each other, and whose tip extends to the vicinity of the first opening and cooperates with the first and second conductive plates. a radiating element provided in the first opening and electromagnetically coupled to the feed line, and a first conductor plate substantially parallel to the second conductor plate.
and a third conductor plate provided on the opposite side of the conductor plate. (2) a first conductor plate having a first opening; a second conductor plate disposed substantially parallel to the first conductor plate with a gap therebetween and having a second opening at a position corresponding to the first opening; A tri-plate power supply line is provided between a conductive plate and a first and second conductive plate, which are substantially parallel to each other, and whose tip extends to the vicinity of the first opening and cooperates with the first and second conductive plates. and a first and second feed line connected to the tip of the feed line.
A planar antenna comprising: a radiating element provided between the openings; and a third conductive plate provided substantially parallel to the second conductive plate and on the opposite side of the first conductive plate. (3) In the planar antenna according to claim 1 or 2,
A dielectric is provided between the first and second conductor plates, and the second and third
A planar antenna with a dielectric material between the conductor plates.