JPS63190404A - Strip line - Google Patents

Abstract

PURPOSE:To stabilize the electric characteristic of a strip line by providing an air gap between line electrodes so as to eliminate the effect of a low dielectric constant dielectric base due to ambient temperature. CONSTITUTION:Dielectric bases 2, 2 are supported with a prescribed interval (a) by a projection strip 20 of supports 14, 14. As a result, the line electrodes 10, 10 formed to other major faces 8, 8 of the dielectric bases 2, 2 are supported oppositely without being interposed with a low dielectric constant dielectric base, that is, via the air gap 22. The dimension of the air gap 22 is adjusted freely by adjusting the forming position of the projection part 20 properly. Since only the air gap exists between the line electrodes, disadvantages due to deformed dielectric base caused by the effect of ambient temperature are eliminated entirely and the stable electric characteristic is obtained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a strip line with a so-called triplate structure, which is used, for example, in microwave transmission lines, filters, or microwave integrated circuits using the same. .

(Prior Art) For example, in a microwave integrated circuit, a strip line having a tribrate structure as shown in FIG. 2 is used as a transmission line.

The stripline shown in FIG. 2 includes two dielectric substrates 2, 2 made of ceramic, for example.

Ground electrodes 6, 6 are formed on one main surface 4.4 of each dielectric substrate 2, 2. A line electrode 10.degree. 10 is formed on the other main surface 8.8 of the dielectric substrates 2,2.

It is known that in a stripline with such a structure, there are two types of microwave transmission modes, odd and even, but in order to combine these transmission modes into one, the stripline shown in Figure 2 has line electrodes. 10 and 10 have a structure in which they are directly electrically and mechanically connected to each other.

However, in such a structure, the line electrodes 10,'
A strip line as shown in FIG. 3 has been proposed because stable contact conduction between the lines is difficult and it is poor in mass production.

That is, FIG. 3 is a conventional example proposed to overcome the drawbacks of the stripline shown in FIG.
Portions corresponding to those in the figure are given the same reference numerals. Third
In the figure, the structure different from that of FIG. 2 is that a dielectric substrate t2 with a low dielectric constant is sandwiched between the line electrodes 10 and 10, and the line electrodes 10 and 10 are sandwiched in some places. +0 is shorted together.

(Problems to be Solved by the Invention) However, in the case of the conventional example shown in FIG. This can cause problems such as performance deterioration due to inhalation of Such deformation and moisture absorption are of course undesirable in terms of stabilizing the electrical characteristics of the strip line.

An object of the present invention is to provide a stripline having such a structure that is not affected by ambient temperature and has stable electrical characteristics.

(Means for Solving the Problems) In order to achieve the above object, the strip line of the present invention includes two dielectric substrates each having a ground electrode formed on one main surface and a line electrode formed on the other main surface. The two dielectric substrates are supported at a predetermined distance with the other main surfaces facing each other, and in this supported state, the dielectric substrates are formed on both dielectric substrates. A gap is formed between the line electrodes.

(Function) In the above structure, there is no low dielectric constant dielectric substrate between the line electrodes, and only a gap exists between them. Therefore, problems caused by the influence of ambient temperature on the low-permittivity dielectric substrate are solved.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a strip line with a triplate structure according to an embodiment of the present invention, and parts corresponding to those in FIGS. 2 and 3 are given the same reference numerals.

In FIG. 1, 2.2 is two dielectric substrates with a high dielectric constant, 4.4 is one main surface of each dielectric substrate 2.2, and 6
．． 6 is a ground electrode formed on one main surface 4.4; 8.
8 is the other main surface of the dielectric substrates 2, 2, and 10.10 is a line electrode formed on the other main surface 8.8. The configurations up to the above are the same in the conventional example and the embodiment.

This embodiment is characterized by the following structure.

That is, in this embodiment, two dielectric substrates 2.2 are placed at a predetermined distance a with their other principal surfaces 8.8 facing each other.
It is provided with supports 14 and I4 for holding and supporting the structure.

The support body 14.14 is configured to be placed over the left and right ends of the dielectric substrate 2.2 in the drawing, and for this purpose, it is formed by bending the wall portion 16 and the upper and lower edges of the wall portion 16. The bent portion 18 and the wall portion 1 of the dielectric substrate 2.2 are arranged to support the dielectric substrate 2.2 at a predetermined distance a from each other.
6 and a protrusion portion 20 formed vertically.

The dielectric substrate 2.2 is supported by the protruding portion 20 of the support 14.14 at a predetermined distance a, and as a result, a line is formed on the other main surface of the dielectric substrate 2.2 at 8°8. The electrodes 10 and 10 are connected to each other without intervening a low-permittivity dielectric substrate as shown in FIG.
They will be supported facing each other via 2.

It goes without saying that the size of this gap 22 can be freely adjusted by appropriately adjusting the formation position of the protrusion portion 20.

In addition, in a triplate structure in which line electrodes are usually opposed between two dielectric substrates, there are two types of transmission modes for microwave waves (odd and even modes), and short-circuit conductors are usually connected at appropriate places. is used to electrically short-circuit the upper and lower line electrodes. However, in this example, as a result of the presence of a gap between the line electrodes, the propagation constant of the odd mode is considerably smaller than that of the even mode. The resonance frequency difference between
If it is a narrow band filter, transmission is possible only by using the even mode, so the short circuit conductor is not necessarily necessary in this embodiment.

(Effects) As is clear from the above explanation, according to the present invention,
There is no low dielectric constant dielectric substrate between the line electrodes,
Since only a gap exists, the dielectric substrate interposed between the line electrodes as in the conventional example would cause problems such as deformation of the dielectric substrate as described above due to the influence of ambient temperature. will be completely eliminated.

Therefore, according to the present invention, it has become possible to obtain a stripline with stable electrical characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a stripline according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional stripline, and FIG. 3 is a sectional view of another conventional stripline. 2.2 is a high dielectric constant dielectric substrate, 6.6 is a ground electrode,
10. IQ is a line electrode, 1. i, +4 is a support. Figure 2 Figure 3

Claims (1)

[Claims] (1) Two dielectric substrates each having a ground electrode formed on one main surface and a line electrode formed on the other main surface are placed at a predetermined interval with the other main surfaces facing each other. The strip line is supported, and in this supported state, a gap is formed between the line electrodes formed on both the dielectric substrates.