JPH02141105A - Planar array antenna - Google Patents

Abstract

PURPOSE:To suppress radiation loss more and to expand the frequency band width by adopting a suspended line feeding circuit structure in which an antenna base is clipped by upper and lower ground plates and the constitution such that a resistive element is arranged in a hole of the upper ground plate. CONSTITUTION:The antenna base 12 is provided with a film base 12b in which a radiation element 3 and a feeder 15 are formed on a film 12a and formed by cladding a copper film 12c on the upper face afterward. The feeder 15 is clipped contactless (in floating state in air) between upper and lower ground plates 10, 11. Then a cavity 18 having a gap l is formed by a step 11a provided to a lower face 10a of the ground plate 10 and to an upper face of the ground plate 11 to constitute a suspended line feeder circuit. Moreover, a hole 17 is formed to the upper ground plate 10 opposite to the radiation element 13. The film 14a supporting the resistive element 14 is supported by a seat 16 in the hole 17 and the distance between the resistive element 14 and the radiation element 13 opposite to each other depends on the height P of the seat 16. Thus, the distance F widening the frequency band width most is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a planar array antenna for satellite broadcast reception, etc., which can simultaneously and easily suppress radiation loss and expand frequency bandwidth.

(Prior Art) As is well known, one of the characteristics of an antenna is the problem of gain, and another is the problem of frequency bandwidth.

Therefore, as a high-performance antenna, an antenna with a high gain and a wide frequency bandwidth is desired.

Conventionally, the measurement data shown in the table below has been known as the radiation loss of an antenna that uses a conductor for the feed line, for example.
As is clear from this measurement data, in order to achieve high gain in this type of antenna, it is considered optimal to use a suspended line feeding circuit.

As shown in FIG. 6, the planar array antenna constituting the feed line loss has an antenna substrate 4 in which upper and lower ground plates 1 and 2 formed of metal or metallized plastic form a microstrip line 3 in a cavity 5. crowded,
It is configured to suppress radiation loss from the feeder line of the microstrip line 3.

On the other hand, a method of expanding the frequency bandwidth, for example 11.7
As shown in Figure 7, a grounding A dielectric 8 is provided on the conductor 7, and Micros! - It is known that a rip line 9 is provided and a parasitic element 11 is provided on a conductor patch provided on a dielectric 10 at a position spaced apart from the center of the radiating element 9a of an antenna configured with a microstrip line 9. It is being

(Problem to be solved by the invention) However, as is clear from the above measurement data,
With the currently known substrate monthly charges, it is not possible to expect any radiation loss effect beyond that of the suspended line, and it is considered difficult to achieve higher antenna gain.

In addition, in the suspended line structure, the distance d is set as the optimal value to suppress radiation loss, depending on the characteristics of the material and circuit used for the antenna board, and in this state, it is used for satellite broadcasting. 11.7GI
12 from Iz. It is considered to be extremely difficult to construct a planar array antenna having a frequency bandwidth sufficient to cover the frequency of 0 GIIz with the desired characteristics of V, S, W, R1,3 or less.

For this reason, currently, increasing the gain of the antenna and expanding the frequency bandwidth are dealt with by independent methods or independent configurations, but the present invention aims to increase the gain by suppressing radiation loss. The object of the present invention is to provide a planar array antenna that can simultaneously and easily expand the frequency bandwidth.

(Means for Solving the Problems) In order to achieve the above objects, the present invention provides a system in which the feeder line of a planar array antenna is suspended in the air between upper and lower ground plates formed of metal or metallized plastic. In a suspended line-fed planar array antenna that is held between Radiation loss can be suppressed by adjusting the distance between the upper and lower grounding plates and the feeder line.
J, and by adjusting the placement depth of the parasitic element in the hole of the main ground plate, the spacing between the radiating element and the parasitic element is adjusted, and the frequency bandwidth is expanded. .

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 1 is a perspective sectional view showing the structure of a planar array antenna according to the present invention, Fig. 2 is an enlarged sectional view showing the main parts in Fig. 1, and Fig. 3 Ca) and (b) show parasitic elements and FIG. 4 is a perspective sectional view showing the main parts of the lower ground plate according to the present invention, and FIG. 5 is a perspective view showing the main parts of the main ground plate according to the present invention. FIG.

12 in the figure is an antenna board, and this antenna board 12
is a thin film such as thin PET or polyimide 1
A film substrate 12b is provided on which copper or aluminum foil is bonded or vapor-deposited and etched to form a radiation element 13 and a power supply line 15, and then a copper film 12c is laminated on the upper surface.

14 is a parasitic element, and this parasitic element 14 is made by adhering or vapor depositing copper or aluminum foil on a thin film such as PET or polyimide, and etching the outer periphery in the same manner as the antenna substrate 12. A parasitic element 14 having a desired shape with a projecting film portion 14a is formed.

On the other hand, the upper and lower grounding plates 10.11 are made of metal or metallized plastic such as ABS, and the power supply line 15 is sandwiched between the upper and lower grounding plates 10.11 in a non-contact state (floating in the air). It is arranged in a so-called suspended structure. The upper and lower ground plates 10.11 are spaced apart by a stepped portion 11a provided on the lower surface 10a of the main ground plate 10 and the upper surface of the lower ground plate 11 in order to have a suspended structure that can suppress radiation loss to the maximum. A cavity 18 is formed to constitute a suspended line power supply circuit section.

In addition, the radiation element 1 formed at the end of the feeder line 15
A hole 17 is formed in the second ground plate 10 facing the second ground plate 10 so that the parasitic element 14 can be buried therein by locking the film portion 14a.

The film portion 14a supporting the parasitic element 14 is supported by the pedestal portion 16 in the hole 17, and therefore the pedestal portion 1
The facing distance between the parasitic element 14 and the radiating element 13 is determined by the height F of 6, and the distance F that allows the frequency bandwidth to be widest is selected.

Furthermore, the upper and lower grounding plates 10.11 are plated with copper or the like in their entirety or at least on the side facing the antenna board 12.

Next, referring to FIG. 2, the assembly process for $1η will be explained.

A parasitic element 14 provided with a film portion 14a on its outer periphery is inserted into a hole 17 formed in the main grounding plate 10.

At this time, the radiating element 13 and the parasitic element 14 are arranged concentrically and facing each other at a distance F, and the film part 14a is fixed to the pedestal part 16 in the hole 17 with an adhesive. (P
>0) (see Figure 2).

Next, the main grounding plate 1o provided with the parasitic element 14 and the lower grounding plate 11 are arranged to face each other, the antenna board 12 is inserted into the cavity 18, and the main grounding plate 1o and the lower grounding plate 11 are are fixed via bolts or the like at a position that does not damage the circuit pattern (path shown) on the antenna board 12 to form a desired planar array antenna.

That is, in the present invention, the lower surface 10a of the main grounding plate 10 and the stepped portion 11a of the lower grounding plate 11 are formed so as to form the rectangular cavity 18 with dimensions that can suppress radiation loss to the maximum extent. A parasitic element is disposed at a position corresponding to the radiating element 13 of the feeding antenna substrate 12 inserted in the cavity 18, separated by a distance F that allows the widest frequency bandwidth to be maintained.

Therefore, a suspended power supply circuit structure with low radiation loss and a parasitic element are arranged opposite to the radiating element of this suspended power supply circuit in order to obtain a wide frequency bandwidth, and each is configured integrally under optimal conditions. can do.

Moreover, the second ground plate 1 of the planar array antenna according to the present invention
0 and the lower ground plate 11 can be manufactured by aluminum die casting, metal cutting, etc. Furthermore, parasitic element 14
can be formed by integral molding on the main ground plate 10 from the beginning, and can be formed at the same time as the main ground plate 10 is plated.

However, in that case, the thickness of the part where the parasitic element 14 is provided should be selected so that the resin that can be plated does not attenuate the radiated power, and at the same time, the material that can be plated should be selected so as not to attenuate the radiated power. It is necessary to take measures such as plating masking to prevent the part of the film portion 14a (P>0) extending from the outer periphery of the parasitic element 14 from being plated.

(Effects of the Invention) As described above, the planar array antenna according to the present invention has a suspended line feeding circuit structure in which the antenna substrate is sandwiched between the lower ground plate and the parasitic element is inserted into the hole in the ground plate. By configuring it so that it is arranged in such a way, it is possible to suppress radiation loss to a greater extent, and at the same time, it is easy to expand the frequency bandwidth by having a structure in which the facing distance between the radiating element and the parasitic element can be adjusted. can be done.

[Brief explanation of the drawing]

Fig. 1 is a perspective sectional view showing the structure of a planar array antenna according to the present invention, Fig. 2 is an enlarged sectional view showing the main parts in Fig. 1, and Fig. 3 (a) and (b) are the parasitic elements and FIG. 4 is a perspective sectional view showing the main parts of the lower ground plate according to the present invention, and FIG. 5 is a perspective view showing the main parts of the second ground plate according to the present invention. A perspective sectional view showing the part, No. 6
The figure is a sectional view showing a conventional suspended line structure, and FIG. 7 is an exploded perspective view showing the arrangement of parasitic elements and radiating elements in a conventional antenna. 14... Parasitic element 15... Feed line 18... Cavity 10... Main ground plate 11... Lower ground plate 12... Antenna board 13... Radiation element (a) Fig. 3 Figure 1 Figure 4 Figure 2 Figure 5

Claims (1)

[Claims] 1. In a suspended line-fed planar array antenna in which a feeder line of a planar array antenna is held between upper and lower ground plates formed of metal or metallized plastic in a suspended state, the feeder line is By arranging the radiating element formed at the end and the parasitic element placed in the hole formed in the upper ground plate to face each other at a predetermined interval, and adjusting the interval between the upper and lower ground plates and the feeder line. In addition to suppressing radiation loss, the frequency bandwidth was expanded by adjusting the distance between the radiating element and the parasitic element by adjusting the placement depth of the parasitic element in the hole in the upper ground plate. Features a flat array antenna.