JP3004439B2 - Planar antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a triplate type planar antenna used for transmission and reception in a microwave band.

[0002]

2. Description of the Related Art As a means of improving the antenna efficiency of a planar antenna, a preliminary report B of the National Convention of the Institute of Electronics, Information and Communication Engineers 1988
As shown in −39 “Microstrip antenna with window fed by triplate line”, there is a method of reducing the loss of the feed line using the triplate line. As shown in FIGS. 3 (a) and 3 (b), the configuration of this antenna is such that a ground conductor 1 and a dielectric 2 are disposed on the surface of the ground conductor 1, and a radiating element is disposed on the surface of the dielectric 2. An antenna circuit including the feed line 4 and the feed line 5 is formed, a dielectric 21 is formed on the surface thereof, and the ground conductor 11 having the slot 3 is arranged on the surface so that the slot 3 is directly above the radiating element 4. are doing.

[0003]

However, in the conventional antenna as shown in FIG. 3, if the power radiated from the radiating element 4 is only radiated from the slot 3 to the space as shown in FIG. However, as shown by B in the figure, the power that propagates between the ground conductor 1 and the ground conductor 11 and radiates may decrease depending on the physical positional relationship with the adjacent radiating element 4. Further, the transmitted power of B may be radiated from the adjacent slot 3 to cause disturbance in the directivity of the antenna.

In order to solve such a problem, the power radiated from one radiating element 4 and the adjacent radiating element 4
, The phase of the power propagating between the ground conductor 1 and the ground conductor 11 must be matched, and for that purpose, the interval between the adjacent radiating elements 4 is uniquely determined. For example, when radiating elements are arranged on a grid with a fixed interval, this interval is about 0.9 times the free space wavelength λ ₀ of the center frequency of the radio wave used.

However, in order to increase the efficiency of the antenna, the interval between the radiating elements 4 must be set to 0.7 to 0.8 times the free space wavelength λ ₀ of the center frequency of the radio wave used. In the prior art, the arrangement density of the radiating elements 4 cannot be increased for the above-described reason.

[0006] The present invention is, to maintain the directional little unnecessary radiation
It is another object of the present invention to provide a highly efficient planar antenna.

[0007]

As shown in FIGS. 1 (a) and 1 (b), a planar antenna according to the present invention comprises a ground conductor 1 and a dielectric 2 disposed on the ground conductor 1. On dielectric 2
A feed radiation element 4 forming the antenna circuit including the power feeding line 5, the dielectric 21 is formed on the its slot 3 on the its
In the planar antenna of the ground conductor 11 is slot 3 formed by arranging so that just above the feed radiation element 4 having a dielectric 22 provided on the ground conductor 1, the power supply comprising a yet still of their the parasitic element 6 to a position directly above the radiating element 4 and the slot 3 is provided, the feed is connected to the feed radiation element 4 on its line 5 and a reverse parallel orientation to each other 2
A feed line 8 is connected to the parasitic element 6 with a length of approximately 波長 wavelength in two directions perpendicular to the direction, and a radiating element 7 is connected to each feed line 8. Is what you do.

As shown in FIGS. 2A and 2B, the feed line 8 is provided only in two directions parallel to the feed line 5 connected to the feed radiating element 4 and opposite to each other . The radiating element 7 is connected to each feed line 8.

[0009]

According to the structure of the present invention, the feed radiating elements 4 are provided at intervals which do not interfere with each other as in the conventional antenna, and the parasitic element 6 which is a feature of the present invention is the same as the conventional planar antenna. And the radiating element 7 connected to the parasitic element 6 can be an antenna that operates together with the ground conductor 11, and the feed line 5 having a branch or bend is connected to the ground conductor 1 and the ground conductor 11. As a result, unnecessary radiation from the shield can be suppressed. Therefore, the radiating element 7 is not limited in its element interval, and can be designed suitable for enhancing the efficiency of the antenna. When linearly polarized light is used, the radiating element 7 can be connected only in two directions parallel to the feed line 4 as shown in FIGS. 2 (a) and 2 (b). The interval between the power supply elements 6 can be freely set.

[0010]

1A and 1B, a ground conductor 1 is made of an aluminum plate having a thickness of 3 mm, and a dielectric 2 is made of foamed polyethylene having a thickness of 2 mm (relative permittivity εr ≒ 1. 1) using a copper foil using four square patches of 9.6 mm × 9.6 mm were formed by etching, the element interval is 44.72mm as feed radiation element 4, the feed line 5 is the sheet
The same material as that of the radiating element 4 which was simultaneously etched was used. The dielectric 21 is made of foamed polyethylene having a thickness of 2 mm (relative permittivity εr ≒ 1.1), the same as that of the dielectric 2, and the ground conductor 11 is made of an aluminum plate having a thickness of 0.5 mm. Four 13 mm slots 3 were formed. Further, a foamed polyethylene having a thickness of 2 mm (dielectric constant εr） 1.1) is used as the dielectric 22, and a 10 mm × 10 m
4m passive elements are formed, and 10m
A radiating element 7 was formed by connecting square patches of m × 10 mm. At this time, the arrangement interval between the parasitic element and the radiating element 7 was 20 mm. The antenna of this example exhibited a gain of about 21.5 dB at a frequency of 11.85 GHz.

[0011]

As described above, according to the present invention, it is possible to provide an antenna with high efficiency without unnecessary radiation or disturbance in directivity even if the limitation on the element spacing is small.

[Brief description of the drawings]

FIG. 1A is a top view showing an embodiment of the present invention, and FIG. 1B is a cross-sectional view thereof.

FIG. 2A is a top view showing another embodiment of the present invention, and FIG. 2B is a sectional view thereof.

3A is a top view showing a conventional example, and FIG. 3B is a cross-sectional view thereof.

[Explanation of symbols]

1,11. Earth conductor 2, 21, 22,.
Dielectric 3. Slot 4. Feeding radiation element 7. Radiating element 5,8. Feed line

Continuation of the front page (72) Inventor Takao Murata 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Research Institute (56) References JP-A-3-101507 (JP, A) JP-A-5-101 152830 (JP, A) JP-A-3-151702 (JP, A) JP-A-2-252304 (JP, A) JP-A-63-135003 (JP, A) JP-A-61-281704 (JP, A) JP-A-63-300606 (JP, A) JP-A-1-307304 (JP, A) US Pat. No. 3,770,075 (US, A) US Pat. No. 4,450,449 (US, A) US Pat. No. 4,899,164 (US, A) US Pat. 1185440 (SU, A) USSR patent invention 907644 (SU, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 13/08 H01P 5/02 603 H01Q 21/06

Claims (2)

(57) [Claims] 1. A ground conductor (1), a dielectric (2) is disposed on the ground conductor (1), the feed radiation element (4) on the dielectric (2)
And forming the antenna circuit comprising a feed line (5), a dielectric (21) is formed on the its slot the ground conductor (11) having a slot (3) on the its (3) feeding radiation In the planar antenna arranged so as to be directly above the element (4), the ground conductor
(11) a dielectric (22) provided on the, the parasitic element (6) provided in addition a position directly above the said feed radiating element on the A and of that (4) and slots (3), its On the feed radiating element (4)
Parallel to the feeder line (5) at the connection with
The feed line (8) is connected to the parasitic element (6) with a length of approximately 波長 wavelength in two directions opposite to each other and two directions orthogonal to the direction, and each feed line (8) is connected to the feed line (8). A planar antenna to which a radiating element (7) is connected. 2. A ground conductor (1), a dielectric (2) disposed on the surface of the ground conductor (1), and a feed radiating element on the surface of the dielectric (2).
Forming the antenna circuit comprising (4) and the feed line (5), the <br/> on of that form dielectric (21), a ground conductor (11) having a slot (3) on top of its In the planar antenna having the slot (3) arranged directly above the radiating element (4), the ground conductor (1
1) a dielectric (22) provided on the further comprising a top of its
Feed radiation element (4) and slot parasitic element (6) provided in a position directly above the (3), wherein the feeding radiation element on the surface (4)
Parallel to the feeder line (5) at the connection with
In the opposite two directions, the feeder line (8) was connected to the parasitic element (6) with a length of about 波長 wavelength, and the radiating element (7) was connected to each feeder line (8). A planar antenna characterized by the above-mentioned.