JPH07273536A - Manufacture of tri-plate power feeding plane antenna - Google Patents

Abstract

PURPOSE:To improve characteristics by supporting a slot plate and a ground conductor to a desired point of the ground conductor at a prescribed interval, thereby uniformizing support distance between the ground conductor and the slot plate even at a high frequency band such as a millimeter band. CONSTITUTION:In order to couple and fix a ground conductor 1 and a slot board 6, a rivet 9 is inserted to a hole 8 penetrated from the slot board 6 to a seat 7 of the ground conductor 1 and the upper part of the slot board 6 is projected and caulked. For example, the ground conductor 1 is formed by aluminum diecast, the thickness of a major part is selected to be 2mm, the height of the seat 7 is selected to be 1mm and the hole 8 is provided thereto. The thickness of the lower dielectric body 2 and the upper dielectric body 2 made of propylene foam whose specific dielectric constant is nearly 1.1 is made to be 0.5mm. A polyimide film laminated with a copper foil whose thickness is 18mum is adopted for a substrate a and a square radiation element and a feeder of the antenna circuit 3 are formed by etching. Moreover, an aluminum board thickness is 0.7mm is used for the slot board 6 and a slot opening 5 is provided thereto 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a triplate-fed planar antenna used for millimeter-wave transmission and reception.

[0002]

2. Description of the Related Art As a means for improving the antenna efficiency of a plane antenna, there is a method of reducing the loss of a feed line by using a triplate line. The basic configuration of this type of antenna is
As shown in FIG. 8, the ground conductor 1, the film substrate 4 on which the antenna circuit 3 is formed, and the slot plate 6 having the slot openings 5 are laminated and arranged with the lower dielectric 2 and the upper dielectric 2 ′ interposed therebetween. It is a thing. The structure of the radiating part is shown in FIG.
There is a type in which a radiating element is provided at the end of the antenna circuit 3 as shown in FIG. 2 or an open line end is provided as shown in FIG.

Since the antennas having such a structure are triplate line structures in which the ground conductor 1 and the slot plate 6 are arranged above and below the antenna circuit 3, there is no need for a bend in the feed line or a discontinuity such as a branch. Since the radiation can be suppressed, it is useful as a method for constructing a highly efficient planar antenna.
The type of (a) has already been reported by the present inventors in Proposals B-102 and B-103 of the 1991 Spring National Convention of the Institute of Electronics, Information and Communication Engineers. In this type of antenna, it is important to keep the distance between the ground conductor 1 and the film substrate 4 and the slot plate 6 uniform, and as shown in FIG. It is common to hold down. Further, for low-frequency applications where the influence of the adhesive is small, a laminate using the adhesive as shown in FIG. 9B is also common.

[0004]

On the other hand, in such a triplate feed type planar antenna, when an antenna having an extremely high frequency band such as a millimeter wave band is constructed, the thickness of the dielectrics 2 and 2'is also extremely large. Since it is thin and weak in strength, stress is generated in the screwed portion of the slot plate 6 and floating occurs in the portion other than the screwed portion of the slot plate 6, and the directional characteristics of the antenna deteriorate due to the excitation phase error. There was a problem. Further, the method using the adhesive has a problem that the loss of the adhesive is large and the antenna gain is reduced at the current technical level. The present invention provides a method for manufacturing a triplate-fed planar antenna capable of maintaining a uniform holding distance between a ground conductor and a slot plate even in a high frequency band such as a millimeter wave band and realizing good antenna characteristics. To do.

[0005]

According to the method of manufacturing a triplate-fed planar antenna of the present invention, a film substrate having an antenna circuit is placed on the surface of a ground conductor via a lower dielectric, and the film is further mounted. In a method of manufacturing a triplate-fed planar antenna in which a slot plate having a plurality of slot openings is placed and fixed on the surface of a substrate through an upper dielectric,
A pedestal is provided at a desired position of the ground conductor for holding the slot plate and the ground conductor at a predetermined distance, and a hole is provided from the slot plate to the pedestal, and a rivet is inserted into the hole. Then, the rivet protruding from the upper part of the slot plate or the lower part of the ground conductor is caulked, or the rivet is press-fitted from above the slot plate to fix the ground conductor and the slot plate.

In order to connect and fix the ground conductor 1 and the slot plate 6 shown in FIG. 1, the rivet 9 is penetrated from the slot plate 6 to the pedestal portion 7 of the ground conductor 1 as shown in FIG. 2 (a). Through the hole 8 provided in the slot plate 6 so that the slot plate 6 is projected and caulked, or the rivet 9 is inserted through the opposite direction and projected to the bottom of the ground conductor 1 as shown in FIG. By squeezing or by pressing the rivet 9'from above the slot plate 6 as shown in FIG. The hole provided in the pedestal portion is a through hole in the case of the crimping method, but may be penetrated as shown in FIG. 3 in the case of the press-fitting method or may not be penetrated though not shown. As described above, by mechanically supporting the pedestal portion, the distance between the slot plate and the ground conductor can be accurately maintained even if pressure is applied and fixed using rivets. In the present invention, as shown in FIG. 4, on the surface of the ground conductor 1 opposite to the surface on which the slot plate 6 is fixed,
A recess 10 formed by forming a step around the hole 8 and a step with the hole 8.
Is preferable because the rivet 9 does not protrude from the opposite surface.

Further, as shown in FIGS. 5 and 6, the height of the pedestal 7 is made equal to the thickness of the lower dielectric 2, and the upper dielectric 2 ′ is placed at a position where the pedestal 7 contacts the slot plate 6. If the rim portion 11 having a height corresponding to the thickness is provided and the film substrate 4 is sandwiched between the slot plate 6 and the pedestal portion 7, the film substrate can be accurately positioned between the slot plate and the ground conductor. It is preferable because it can be held well. Further, as shown in FIG. 7, it is preferable to form the rising portion 12 on the outer peripheral portion of the slot plate 6 because the strength is increased and the flatness of the slot plate can be maintained. The figure (a) is an example in which the rising portion 12 is directed downward, and the figure (b) is an example in which the rising portion 12 is provided upward from the rim portion 11 provided on the outer peripheral portion.

With the above-mentioned structure, the slot plate and the film substrate are accurately held on the surface of the ground conductor, so that a triplate line with a small phase error can be formed and the directivity of the antenna is disturbed. Gain reduction can be suppressed.

[0009]

EXAMPLES Examples of the present invention will be described below. Example 1 FIG. 1 is a perspective view showing a configuration of an antenna in a method for manufacturing a triplate feed type planar antenna according to an example of the present invention. In the figure, the ground conductor 1 used is one in which the thickness of the main part formed by aluminum die casting is 2 mm and the height of the pedestal 7 is 1 mm. Holes 8 that penetrate the pedestal 7
Was set up. The lower dielectric 2 and the upper dielectric 2 ′ are made of polypropylene foam having a thickness of 0.5 mm and a relative dielectric constant of about 1.1. As the film substrate 4, a polyimide film having a thickness of 25 μm and a copper foil having a thickness of 18 μm are used. The pasted one was used. The antenna circuit 3 has a frequency of 60 G on one side.
A square radiating element and a feed line having 0.26 times the free space wavelength λ ₀ of Hz were formed by etching. Furthermore,
Using a 0.7 mm aluminum plate, a slot plate 6 was formed by punching so that one side of the slot opening 5 was a square with 0.6 times λ ₀ .

With the above arrangement, a 256-element array was formed by arranging the radiating elements and the slots in a square arrangement at a distance of 0.9 times λ ₀ . Next, as shown in FIGS. 2A and 2B, the rivet 9 is inserted into the hole 8 and the rivet 9 is caulked at the upper part of the slot plate 6 or the lower part of the ground conductor 1 to make the ground conductor 1 and the slot plate. A sample in which 6 and 6 were fixed was manufactured. A characteristic grasping test was conducted by penetrating the ground conductor 1 from the back surface of these samples and supplying power from a waveguide. As a result, in both samples, the first side lobe level in the directional pattern was -1.
It has been confirmed that the characteristic is almost equal to the theory at 2.5 dB or less, and the gain is a good characteristic of 32 dB.

Embodiment 2 Fixing the ground conductor 1 and the slot plate 6 in Embodiment 1
As shown in FIG. 3, a sample was manufactured in the same manner as in Example 1 except that the rivet 9'was press-fitted, and the above test was performed.
As a result, the same good characteristics as in Example 1 were confirmed.

Embodiment 3 A hole is formed around the hole 8 on the surface of the ground conductor 1 in the embodiment 1 opposite to the surface on which the slot plate 6 is fixed so that the rivet 9 does not project from the opposite surface. 8 to form a recessed portion 10 that has been machined and inserts a rivet 9 into the hole 8
A sample in which the ground conductor 1 and the slot plate 6 were fixed by caulking the rivets 9 on the slot plate 6 was manufactured. After that, the same test as in Example 1 was performed, and as a result, the same good characteristics as in Example 1 were confirmed.

Example 4 As the ground conductor 1, a main part formed by aluminum die casting having a thickness of 2 mm and a pedestal 7 having a height of 0.5 mm was used, and a 0.7 mm aluminum plate was used as the slot plate 6. Also, an antenna was prepared in the same manner as in Example 1 except that the rim portion 11 shown in FIG. 6 was pressed so that the height was 0.5 mm (the configuration of the slot opening 5 was the same as that in Example 1). A sample in which the ground conductor 1 and the slot plate 6 were fixed by press-fitting the rivet 9 ′ into the hole 8 as shown in FIG. 6 was manufactured. After that, the same test as in Example 1 was performed, and as a result, the same good characteristics as in Example 1 were confirmed.

Embodiment 5 The slot plate 6 in Embodiments 1 and 4 is bent, and as shown in FIGS. 7 (a) and 7 (b), the rising portion 12 having a height of 1 mm is directed downward and upward on the outer peripheral portion. Samples were manufactured in the same manner as in Example 2 and Example 4 except that the sample having the above was used. After that, the same test as in Example 1 was performed, and as a result, both samples were confirmed to have the same good characteristics as in Example 1.

[0015]

According to the present invention, even in a high frequency band such as a millimeter wave band, the holding distance between the ground conductor and the slot plate can be kept uniform, and the triplate-fed plane having good antenna characteristics can be obtained. The antenna can be manufactured at a lower cost and in a shorter time than ever before.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an antenna according to an embodiment of the present invention.

2 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIG.

FIG. 3 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIG.

4 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIG.

FIG. 5 is a perspective view showing the configuration of an antenna in a method for manufacturing a triplate feed type planar antenna according to another embodiment of the present invention.

6 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIG.

FIG. 7 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIGS. 1 and 6.

FIG. 8 is a perspective view showing a basic configuration of a conventional triplate feed type planar antenna.

9 is a cross-sectional view showing a method of fixing the ground conductor and the slot plate of the antenna of FIG.

[Explanation of symbols]

1 ... Ground conductor, 2 ... Lower dielectric, 2 '... Upper dielectric, 3 ...
Antenna circuit, 4 ... Film substrate, 5 ... Slot opening,
6 ... Slot plate, 7 ... Pedestal part, 8 ... Hole part, 9 ... Rivet, 9 '... Rivet, 10 ... Recessed part, 11 ... Rim part, 12
… Rise

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kura Mizukaki 1150 Goshomiya, Shimodate City, Ibaraki Prefecture Inside the Yuki Plant of Hitachi Chemical Co., Ltd. (72) Kiichi Kanamaru 1150 Gogomiya, Shimodate City, Ibaraki Prefecture Hitachi Seiko Co., Ltd. Yuki factory

Claims (4)

[Claims] 1. A slot having a film substrate on which an antenna circuit is formed on a surface of a ground conductor via a lower dielectric and further having a plurality of slot openings on the surface of the film substrate via an upper dielectric. In a method for manufacturing a triplate-fed planar antenna in which a plate is placed and fixed, a pedestal part for holding the slot plate and the ground conductor at a predetermined distance is provided at a desired position of the ground conductor, and A hole is provided from the slot plate to the pedestal, and a rivet is inserted into the hole to crimp the rivet protruding above the slot plate or below the ground conductor, or by pressing the rivet from above the slot plate. , A method of manufacturing a triplate-fed planar antenna, characterized in that a ground conductor and a slot plate are fixed. 2. A recess formed by forming a step and a step around the hole so that the rivet does not protrude from the surface of the ground conductor opposite to the surface fixing the slot plate. The method for manufacturing a triplate-fed planar antenna according to claim 1, which is formed. 3. The height of the pedestal corresponds to the thickness of the lower dielectric, and the rim having a height corresponding to the thickness of the upper dielectric is provided at a position where the pedestal contacts the slot. The method for manufacturing a triplate-fed planar antenna according to claim 1, wherein the film substrate is sandwiched between the pedestal and the base. 4. The method for manufacturing a triplate-fed planar antenna according to claim 1, 2 or 3, wherein a rising portion is provided on an outer peripheral portion of the slot plate.