JP2898659B2 - Microstrip patch antenna with slot plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a microstrip patch antenna used for microwaves.

(Prior Art) At present, as a microwave band antenna, there are a parabolic antenna and various planar antennas, and particularly, a planar antenna which is easy to handle has been attracting attention since satellite broadcasting started.

For this planar antenna, various antennas such as a microstrip, a radial line, a triplate, and a suspended line have been researched and developed. this house,
In an antenna using a microstrip, as shown in FIGS. 9A and 9B, a ground conductor 2 is provided on one surface of a dielectric 3 and a plurality of radiating elements 4 and feed lines 5 are provided on the other surface. An antenna having a metal plate 7 spaced at a fixed interval on the side of the radiating element 4 and a slot 6 penetrating the metal plate 7 at a position corresponding to the radiating element 4 of the metal plate 7 is provided. Are known.

(Problems to be Solved by the Invention) A conventional microstrip antenna provided with a slot is thin and lightweight, and is easy to manufacture. As a result, there is a problem that the loss due to the feed line increases and the efficiency decreases.

That is, as shown in FIG.
The radiating element 4 is provided on the side of the dielectric 3 where the ground conductor 2 is not provided, and the gain of the antenna provided with the slots 6 at regular intervals is, as shown in FIG. It is determined by the rate and is at most 10 dB or less. Therefore, in order to obtain an antenna having a gain of 30 dB, it is necessary to arrange and connect 500 to 1000 such antennas. When such a large number of antennas are arranged, if the spacing between the radiating elements 4 is increased, the area required for the antennas is increased, so that the length of the feeder line 5 is increased and the loss is increased. Also, if the spacing between the radiating elements 4 is reduced, the electrical coupling between the feeder line 5 and the radiating elements 4 or between the radiating elements 4 becomes stronger and the gain decreases, so even if the arrangement of the radiating elements 4 is devised. , The efficiency when the loss in the feed line 5 is not considered
It was difficult to achieve 90% or more.

An object of the present invention is to provide a microstrip antenna which is excellent in radiation gain and excellent in suppressing loss of a feed line.

(Means for Solving the Problems) In a microstrip antenna according to the present invention, an antenna including a metal plate 7 having a plurality of slots 6, a plurality of radiating elements 4, a ground conductor 2 and a feed line 5, is provided. The ground conductors 2 are arranged at a certain interval from the ground conductors, and the metal plates 7 are arranged at regular intervals on the side where the ground conductor 2 is not provided. The number of slots 6 provided in the metal plate 7 is It is characterized in that the number is larger than the number of the elements 4.

The radiating element 4 may be provided on one surface of the dielectric 3 other than air as shown in FIG. 1 (a), or a part of the dielectric 3 as shown in FIG. 1 (c). As an air layer, as shown in FIG. 1 (d) or (e), provided on both sides of a dielectric 3 other than air, or a film-like dielectric 3 other than air is used. You can also. Also, the ground conductor 2 is, like the radiating element 4,
It can be provided on one surface of the dielectric 3 other than air.
As shown in FIG. 1 (f), (g) or (h), the metal plate 7 can be formed by forming a metal layer 9 on a dielectric material 8, and the slot 6 is formed as shown in FIG. ) May be formed as a hole penetrating the laminate, and a metal-free portion 10 may be formed in the metal layer 9 by etching or the like as shown in FIGS. 1 (f) and 1 (h). it can. Furthermore, the metal layer 9 can be formed on both surfaces of the dielectric 8 as shown in FIG. 1 (h).

As the material of the dielectric 3 used in the present invention, an insulating material having a small dielectric loss tangent and relative permittivity can be used, and the radiating element 4 and the ground conductor 2 do not necessarily need to be bonded and fixed. It is preferable that the shape does not change. As such a dielectric, an organic insulating material is particularly preferable,
A foam containing air can be used therein, and a spacer can be used to support the radiating element 4 and the ground conductor 2, and air can be used as the dielectric 3.

As the ground conductor 2, any metal conductor can be used, and any thickness can be used as long as it can be manufactured by current technology. That is, if a film-like organic insulating material is used as the dielectric material 3, an extremely thin metal layer can be formed on the surface by using a technique such as sputtering or vapor deposition. Alternatively, it is possible to use a metal foil formed by laminating a metal foil formed by electrolytic plating, or to use a metal plate. The material used is aluminum, iron, copper, nickel or alloys with these and other metals, and the selection is made based on economy, weight and required mechanical and electrical properties. .

The radiating element 4 and the feed line 5 may be the same as the above-described ground conductor, and the shape thereof may be processed by selectively etching and removing a metal foil previously bonded to the dielectric 3. A method of manufacturing a wiring board in general, such as a method of forming a required conductor by electroless plating, or a method of using both in combination, or a method of forming a required conductor in a paste form by silk printing. Can be used.

The metal plate 7 can be made of the same material as the ground conductor 2, the radiating element 4, and the feeder 5.
In the slot 6 formed in the same manner as in the method of forming the radiating element 4 and the feeder line 5, a general wiring board manufacturing method can be used. Alternatively, a method used for sheet metal processing can be used.

The number of the slots 6 provided in the metal plate 7 needs to be larger than the number of the radiating elements 4.

Further, as shown in FIG. 1 (b), the arrangement of the slots 6 can be all places which do not correspond to the radiating elements 4 on this metal plate 7, and as shown in FIG. 2 (b). As described above, a part can be provided at a position corresponding to the radiation element 4. In any of the above cases, it is preferable that the metal plate 7 be arranged point-symmetrically with respect to a portion corresponding to the radiating element 4, and it is more preferable that the metal plate 7 be arranged on a concentric circle.

The shape of the slot 6 may be a circle, a square, a cross, or an X as long as the shape is used for an antenna having a slot 6 that penetrates a metal plate 7 at a position corresponding to a conventional radiating element 4.
Any shape such as a letter shape can be used.

A certain number of such slots 6 are replaced with one radiating element 4
To form a group of antenna elements, and a plurality of antenna groups are arranged to form one planar antenna. However, if one or more slots 6 are shared by adjacent antenna groups, the area of the antenna can be effectively used. preferable. As an example, FIG. 4 (a) shows a case where the slot 6 is provided only at a position not corresponding to the radiating element 4, and FIG. 4 (b) shows a case where the slot 6 is also provided at a position corresponding to the radiating element 4. And FIG.

(Operation) As a result of intensive studies, the inventors of the present invention have found that, as shown in FIG. 1, if a slot 6 is provided at a location that does not correspond to one radiating element 4, the gain is improved. It has been found that a slot 6 may be provided at a position corresponding to the radiating element 4. The microstrip antenna of the present invention has been made based on this finding. The reason is 1
Since the radio waves radiated from the two radiating elements 4 are dispersed in each of the plurality of slots 6 provided in the metal plate 7 and radiated into the space, the beam width is narrowed and the gain is improved.

Example 1 The structure shown in FIGS. 1 (a) and 1 (b) was used, and the thickness was 1 mm.
An aluminum plate, a foamed polyethylene sheet with a relative dielectric constant of 1.77 and a thickness of 0.8 mm and a rolled copper foil with a thickness of 35 μm are laminated and etched to feed a patch-type radiating element. A line is formed, and an X-shaped slot 9 is provided for the radiating element 1 with a foam having a relative dielectric constant of about 1 and a thickness of 8 mm on the etched substrate.
A 0.5 mm aluminum plate was stacked to form a microstrip antenna. At this time, the slot is 3mm wide and 1 long
2.5 mm slots are combined in an X-shape, one at a location corresponding to the radiating element and four at equal intervals on a concentric circle at a location with a peripheral radius of 14 mm.

Example 2 The structure shown in FIGS. 2 (a) and (b) was used, and the thickness was 1 mm.
An aluminum plate, a foamed polyethylene sheet with a relative dielectric constant of 1.77 and a thickness of 0.8 mm and a rolled copper foil with a thickness of 35 μm are laminated and etched to feed a patch-type radiating element. A line is formed, and an X-shaped slot 9 is provided for the radiating element 1 with a foam having a relative dielectric constant of about 1 and a thickness of 8 mm on the etched substrate.
A 0.5 mm aluminum plate was stacked to form a microstrip antenna. At this time, the slot is 3mm wide and 1 long
2.5 mm slots are combined in an X-shape, one at a location corresponding to the radiating element, and eight at equal intervals on a concentric circle with a radius of 14 mm around the radiating element.

Example 3 Example 3 was the same as Example 1 except that one slot was provided at a location corresponding to the radiating element, and eight slots were provided at equal intervals on a concentric circle at a location with a peripheral radius of 16 mm.

Example 4 Example 4 was the same as Example 1 except that one slot was provided at a location corresponding to the radiating element, and eight slots were provided at equal intervals on a concentric circle at a location with a peripheral radius of 18 mm.

Example 5 Example 5 was the same as Example 1 except that one slot was provided at a location corresponding to the radiating element and eight slots were provided at equal intervals on a concentric circle at a location with a peripheral radius of 20 mm.

Example 6 Example 6 was the same as Example 2 except that the configuration was changed to FIGS. 3 (a) and 3 (b).

Example 7 Example 7 was the same as Example 3 except that the configuration was changed to FIGS. 3 (a) and 3 (b).

Example 8 Example 8 was the same as Example 4 except that the configuration was changed to FIGS. 3 (a) and 3 (b).

Example 9 Example 9 was the same as Example 5 except that the configuration was changed to FIGS. 3 (a) and 3 (b).

Example 10 The structure was the same as that of Example 1 except that the structure was changed to FIGS. 1 (b) and 1 (c) and an 8 mm thick spacer was used instead of the 8 mm thick foam.

Embodiment 11 Except that the configuration is shown in FIGS. 1B and 1D, the radiating element closer to the metal plate 7 is a parasitic element, and the feeder line 4 is connected to the radiating element closer to the ground conductor 2. Same as Example 10.

Example 12 Except that the configuration was made as shown in FIGS. 1 (b) and 1 (e), and the radiating element closer to the metal plate 7 and the radiating element closer to the ground conductor 2 were supplied with different phases by 90 °. Same as Example 10.

Example 13 The foamed polyethylene sheet having a relative dielectric constant of 1.77 and a thickness of 0.8 mm was used in the same manner as the substrate on which the radiating element used in Example 1 was formed as a dielectric, with the configuration shown in FIGS. And a rolled copper foil having a thickness of 35 μm was laminated, and the same processing as in Example 1 was performed except that a portion having no copper foil was formed in a shape corresponding to the slot 6 by etching. .

Example 14 FIGS. 1 (b) and 1 (g) show the structure of the foamed polyethylene sheet having a relative dielectric constant of 1.77 and a thickness of 0.8 mm, similarly to the substrate on which the radiating element used in Example 1 was formed as a dielectric. And the same procedure as in Example 10 except that the copper foil of the laminate obtained by laminating the rolled copper foil having a thickness of 35 μm was etched to form a portion having no copper foil in a shape corresponding to the slot 6. .

Example 15 FIGS. 1 (b) and 1 (h) show constructions of a foamed polyethylene sheet having a relative dielectric constant of 1.77 and a thickness of 0.8 mm similarly to the substrate on which the radiating element used in Example 1 was formed as a dielectric. And the same procedure as in Example 11 except that the copper foil of the laminate obtained by laminating the rolled copper foil having a thickness of 35 μm was etched to form a portion having no copper foil in a shape corresponding to the slot 6. .

Embodiment 16 As shown in FIG. 4 (b), the number of radiating elements is 256, and one slot 6 is shared with four adjacent antenna elements, and the configuration is the same as that of the first embodiment. (A) and (b).

Embodiment 17 As shown in FIG. 5, the configuration of FIG. 3 is combined with four, and the slot corresponding to one radiating element shares two slots corresponding to the other radiating elements, respectively. The same as above.

Comparative Example The same operation as in Example 2 was performed except that the structure shown in FIG. 10 was used.

The characteristics of the above Examples and Comparative Examples were both investigated at a frequency of 12 GHz.

The radiation characteristics of Example 10 are shown in FIG. 6 (a), the frequency characteristics are shown in FIG. 6 (b), and the radiation characteristics of the comparative example are shown in FIG. As a result, the gain of Example 1 was about
It can be seen that it is improved by 4 dB.

Further, the gains of the antennas of Examples 2 to 9 were
As a result of measurement at z, as shown in FIG. 8, in each case, the gain was improved by about 3 dB or more as compared with the conventional antenna. Furthermore, Examples 10 to 15 were similar.

The values on the vertical axis in FIG. 8 are relative values when the gain of the antenna of the comparative example is 0 dB.

(Effects of the Invention) As described above, according to the present invention, a microstrip antenna having excellent gain and low loss can be provided.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing one embodiment of the present invention, FIG. 1B is a top view showing one embodiment of the present invention, and FIG.
FIG. 1D is a sectional view showing another embodiment of the present invention, FIG. 1D is a sectional view showing another embodiment of the present invention, and FIG. 1E is a sectional view showing another embodiment of the present invention. FIG. 1 (f) is a sectional view showing another embodiment of the present invention, FIG. 1 (g) is a sectional view showing another embodiment of the present invention, and FIG. FIG. 2 (a) is a cross-sectional view showing another embodiment of the present invention, FIG. 2 (b) is a top view showing another embodiment of the present invention, and FIG. a) is a cross-sectional view showing another embodiment of the present invention, FIG. 3 (b) is a top view showing another embodiment of the present invention, and FIG. 4 (a) shows another embodiment of the present invention. FIG. 4 (b) is a schematic diagram showing another embodiment of the present invention, FIG. 5 is a schematic diagram showing another embodiment of the present invention, and FIG.
(A) and (b) are diagrams for explaining the effect of the present invention, FIG. 7 is a diagram for explaining the effect of the conventional example, and FIG. 8 is the effect of another embodiment of the present invention. FIG. 9 (a) is a sectional view showing a conventional example, and FIG. 9 (b)
FIG. 10 is a top view showing a conventional example, and FIG. 10 is a diagram for explaining the conventional example. DESCRIPTION OF SYMBOLS 2 ground conductor 3 dielectric layer 4 radiating element 5 feed line 6 slot 7 metal plate 8 dielectric 9 metal tank 10 Part without metal 11 ... Foam

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Kado 1500 Ogawa Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. (72) Inventor Hiroyuki Iyama 1500 Ogawa Ogawa Shimodate City Ibaraki Prefecture (72) Inventor Mitsuru Hirao, Inventor Mitsuru Hirao 1150 Goshomiya, Shimodate-shi, Ibaraki Hitachi Hitachi Chemical Co., Ltd. (72) Inventor Kenji Oomaru 1-10-10 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute (72) Inventor Takao Murata 1-10-10 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation, Research Institute of Broadcasting Technology (56) References 1989 IEICE Autumn Conference Proceedings [Part 2], Lecture No. B-35, P 2-35 (58 ) investigated the field (Int.Cl. ^6, DB name) H01Q 3/00 - 3/46 H01Q 21/00 - 21/30 H01Q 23/00 H01Q 25/00 - 25/04 H01Q 13/00-13/28

Claims (12)

(57) [Claims] 1. An antenna comprising a metal plate (7) having a plurality of slots (6), a plurality of radiating elements (4), a ground conductor (2) and a feed line (5). The ground conductor (2) is arranged at a certain interval from
A metal plate (7) spaced at a constant interval is disposed on the side without the ground conductor (2), and the number of slots (6) provided in the metal plate (7) is equal to the number of the radiating elements (4). A microstrip patch antenna with a slot plate, characterized in that there are more. 2. A dielectric (8) instead of said metal plate (7).
2. A microstrip patch antenna with a slot plate according to claim 1, wherein a laminated body having a metal layer (9) formed on the surface of the patch strip is used. 3. A microstrip patch antenna with a slot plate according to claim 2, wherein a metal-free portion (10) is formed in a metal layer (9) instead of said slot (6). 4. The radiating element (4) is provided on one surface of a dielectric (3) other than air.
4. The microstrip patch antenna with a slot plate according to any one of 2 and 3. 5. The radiating element (4) is provided on both surfaces of a dielectric (3) other than air.
5. The microstrip patch antenna with a slot plate according to any one of 3 or 4. 6. The method according to claim 1, wherein said derivative (3) other than air is in the form of a film.
The microstrip patch antenna with a slot plate according to any one of the above. 7. The device according to claim 1, wherein said ground conductor is provided on one surface of a dielectric material other than air.
7. The microstrip patch antenna with a slot plate according to any one of 2, 3, 4, 5, and 6. 8. The method according to claim 1, wherein the position of the slot is not a position corresponding to the radiating element. The microstrip patch antenna with the slot plate described in the above. 9. The microstrip patch antenna with a slot plate according to claim 8, wherein a slot (6) is provided at a position corresponding to the radiating element (4) in addition to the slot (6). 10. The radiating element (4) of the metal plate (7).
The slots (6) are arranged point-symmetrically with respect to a position corresponding to (1), (2), (3), (4), (5) and (4).
10. The microstrip patch antenna with a slot plate according to any one of 6, 7, 8 and 9. 11. The device according to claim 1, wherein the slots provided in the metal plate are arranged on a concentric circle. 11. The microstrip patch antenna with a slot plate according to any one of claims, 9 and 10. 12. A radiating element (4) and a fixed number of slots (6) are formed as a group of antenna elements, and a plurality of adjacent groups of antenna elements are formed of a fixed number of slots (6).
Claims 1, 2, 3, 4,
12. The microstrip patch antenna with a slot plate according to any one of 5, 6, 7, 8, 9, 10, and 11.