JPH07254810A - Structure for high frequency circuit - Google Patents

Abstract

PURPOSE:To obtain the structure for the high frequency circuit in which adjustment and manufacture are facilitated by using a fixing means such as a thread so as to fix in common a lower conductor case, a dielectric board and an upper conductor case. CONSTITUTION:A dielectric board 12 is arranged on the surface of a lower conductor case 11. A microstrip line 13 used to send a high frequency signal is formed to the surface of the dielectric board 12. A conductive area 21 is formed between the microstrip lines 13. Lots of throughholes 22 are formed to the conductive area 21 at an interval less than a half wavelength with respect to a frequency of a high frequency signal sent through the microstrip lines 13. The throughholes 22 are used connect electrically the conductive area 21 formed to the surface of the dielectric board 12 and a ground conductor on the rear side. The upper conductor case 15 is arranged on the dielectric board 12. The lower conductor case 11, the dielectric board 12 and the upper conductor case 15 are tightened at four corners by using a fixing means such as a screw 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency circuit structure which constitutes a high frequency switch, a distributor and the like.

[0002]

2. Description of the Related Art A conventional high frequency circuit structure will be described with reference to the perspective view of FIG. Figure 4
Shows an example of a high frequency switch, and 41 is a metal case. Further, for example, the periphery of the case 41 has a wall 42 structure. Then, the dielectric substrate 43 is fixed to a flat portion inside the case 41 surrounded by the wall 42, and the microstrip line 44 is formed on the dielectric substrate 43.
The top of the case 41 is covered with a lid 45, and the case 41 and the lid 4 are covered.
5 is fixed with a screw 46. A connector 47b is formed on the wall of the case 41.

FIG. 5 shows the high-frequency switch shown in FIG.
It is the figure which looked at from above and removed, and the same code | symbol is attached | subjected to the same part as FIG. A wall 42 is formed in the peripheral portion of the case 41 and in a portion extending from one peripheral portion toward the center. A U-shaped dielectric substrate 43 is arranged in conformity with the flat portion of the case 41 surrounded by the wall 42.
Further, one input connector 47 is provided on one side of the case 42.
a and two output connectors 47b, 4 on the other side
7c is formed.

A microstrip line 44 is formed so as to be connected to the input connector 47a, and the microstrip line 44 branches in two directions on the way.
The branched microstrip lines 44 are connected to output connectors 47b and 47c, respectively. Also, 48
Is an electric component mounted on the microstrip line 44, for example, a PIN diode.

FIG. 6 is a view showing the dielectric substrate 43 on which the microstrip line 44 is formed, taken out from the case 41. The same parts as those in FIGS. 4 and 5 are designated by the same reference numerals. As shown in FIG. 6, some electrical components 4 are provided near the branch point of the microstrip line 44.
8, for example a PIN diode is implemented.

In the high frequency switch described above, the electric component 4
8 For example, the bias voltage applied to the PIN diode is controlled so that the signal input from the input connector 47a is output to one of the output connectors 47b and 47c, or the signal is output from any of the output connectors 47b and 47c. I try not to.

By the way, in the conventional high frequency circuit structure, for example, in order to prevent electrical coupling between the branched microstrip lines 44, or to prevent leakage of radio waves to the outside of the case 41, A wall 42 is formed at the periphery or between the branched microstrip lines 44.

The wall 42 of the case 41 is higher than the surface of the dielectric substrate 43. Therefore, the wall 42 of the case 41 becomes an obstacle to the work when the electric component 48 is mounted after the dielectric substrate 43 is incorporated in the case 41 or when the circuit pattern is adjusted. Therefore, the dielectric substrate 43 has to be removed from the case 41 for work, which is complicated.

In order to prevent electrical coupling between the microstrip lines 44, a wall is formed, for example, in the central portion of the case 41. As a result, the shape of the flat part of the case 41 becomes complicated. In such a case, it is necessary to match the outer shape of the dielectric substrate 43 with the flat portion of the case 41, and the dielectric substrate 43 has a complicated shape with irregularities. Therefore, it is difficult to process the dielectric substrate 43, and the dielectric substrate 43 is cracked when the dielectric substrate 43 is processed.
It may warp.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a high frequency circuit structure which can be easily adjusted and manufactured.

[0011]

In the high frequency circuit structure of the present invention, a dielectric substrate arranged on a lower conductor case, a microstrip line formed on the surface of the dielectric substrate, and a microstrip line are formed. A conductive region formed on the surface of the dielectric substrate, a plurality of through holes formed in the conductive region at intervals less than 1/2 wavelength of a signal transmitted through the microstrip line, and the through holes. An upper conductor case, which has a surface that comes into contact with a portion and is disposed on the dielectric substrate, and a fixing unit that integrally fixes the lower conductor case, the dielectric substrate, and the upper conductor case. .

[0012]

According to the above construction, the dielectric substrate on which the microstrip line is formed is sandwiched between the lower conductor case and the upper conductor case, and the lower conductor case, the dielectric substrate and the upper conductor case are screwed or the like. For example, the common fixing means is used. Therefore, when adjusting a high-frequency circuit such as a microstrip line, by removing the upper conductor case, there is no obstruction on the surface of the dielectric substrate, and the work can be easily performed.

Since the dielectric substrate is sandwiched between the lower conductor case and the upper conductor case, a pseudo waveguide is formed by the upper and lower conductor cases and the dielectric substrate. In this case, the signal may be transmitted through the pseudo waveguide. However, a plurality of through holes are formed in the dielectric substrate portion forming the pseudo waveguide at intervals less than 1/2 wavelength of the signal transmitted through the microstrip line. The through hole acts so as to be cut off with respect to the frequency of the signal transmitted through the microstrip line, and prevents the signal transmission in the pseudo waveguide portion. Therefore, electrical coupling between the microstrip lines and leakage of signals to the outside of the case can be prevented.

Further, since no wall is required in the central portion of the case, the dielectric substrate can be formed in a simple shape such as a rectangle, which facilitates manufacturing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the perspective view of FIG. FIG. 1 shows, for example, a high frequency switch, and 11 is a lower conductor case forming the high frequency switch. The surface of the lower conductor case 11 is formed flat, and the dielectric substrate 12 is arranged on the flat surface. The dielectric substrate 12 has the same shape as the surface of the lower conductor case 11, and a microstrip line 13 for transmitting a high frequency signal is formed on the surface thereof. Note that one end of the microstrip line 13 is connected to the output connector 14b.

The upper conductor case 15 is arranged on the dielectric substrate 12, and the dielectric substrate 12 is sandwiched between the lower conductor case 11 and the upper conductor case 15.
In this state, the lower conductor case 11, the dielectric substrate 12, and the upper conductor case 15 are fastened together with fixing means such as screws 16 at the four corners.

FIG. 2 is a diagram showing a portion of the dielectric substrate 12 taken out from the high frequency switch shown in FIG. 1. The input end IN of the microstrip line 13 is composed of one microstrip line, and in two directions in the middle. They are branched and connected to the output terminal OUT. Further, on the surface of the dielectric substrate 12, a conductive region 21 is formed in the peripheral portion and between the branched microstrip lines 13. A large number of through holes 22 are formed in the conductive region 21 at intervals less than 1/2 wavelength of the frequency of the high frequency signal transmitted through the microstrip line 13. These through holes 22 electrically connect the conductive region 21 formed on the front surface of the dielectric substrate 12 and the ground conductor (not shown) on the back surface.

FIG. 3 shows the upper conductor case 15 of FIG. 1, which is upside down from the case of FIG. The upper conductor case 15 and the lower conductor case 11 are disposed between the dielectric substrate 1 and the upper conductor case 15.
When the two are sandwiched, a portion facing the microstrip line 13 (FIG. 1) is a space 15a, and a portion facing the conductive region 21 is a wall 15b. Also,
A groove 31 for mounting an input connector or an output connector is formed in the wall 15b portion of the upper conductor case 15.

When the above-described upper conductor case 15 is arranged on the dielectric substrate 12, the surface of the wall 15b structure of the upper conductor case 15 contacts the through hole 22 formed in the conductive region 21, as shown in FIG. At this time, the dielectric substrate 12
The conductive area 21 and the upper conductive case 15 are in mechanical and electrical contact with each other. Further, the conductive region 21 of the dielectric substrate 12 is connected to the ground conductor (not shown) on the back surface through the through hole 22, and is further electrically connected to the lower conductor case 11.

Therefore, the conductive region 21 on the surface of the dielectric substrate 12 contacts the wall of the upper conductor case 15, and the ground conductor on the back surface contacts the lower conductor case 11. For this reason,
The dielectric substrate 12 is sandwiched between the upper conductor case 15 and the lower conductor case 11, and a pseudo waveguide is formed in this portion.
However, a plurality of through holes 22 are formed in the conductive region 21 of the dielectric substrate 12 at intervals less than 1/2 wavelength of the high frequency signal transmitted through the microstrip line 13. Therefore, the pseudo waveguide is cut off from the high frequency signal transmitted by the microstrip line 13 and cannot transmit the high frequency signal. Therefore, electrical coupling does not occur between the microstrip lines 13 branched through the pseudo waveguide, and no signal leaks to the outside.

As the distance between the through holes 22 is made narrower than half the wavelength of the high frequency signal transmitted through the microstrip line 13, electrical coupling between the microstrip lines 13 and leakage of radio waves can be reduced. A high-frequency circuit with good characteristics can be constructed.

According to the above-mentioned embodiment, it is not necessary to provide a wall between the microstrip lines even when the electrical coupling between the microstrip lines is prevented. Therefore, the shape of the dielectric substrate can be adjusted to the lower conductor case to have a simple shape without unevenness. For this reason, the dielectric substrate 12 is easily processed, and is not cracked or warped during manufacturing.

Also, when the circuit pattern formed on the dielectric substrate is to be corrected, the upper conductor case can be removed so that there is no obstruction on the surface of the dielectric substrate and the adjustment work can be performed easily.

Further, if the dielectric substrate is commonly fixed to the upper conductor case or the lower conductor case with screws, the work of separately fixing the lower conductor case and the dielectric substrate becomes unnecessary,
It also takes less time to assemble.

[0025]

According to the present invention, a high frequency circuit structure which can be easily manufactured and adjusted can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an embodiment of the present invention.

FIG. 3 is a perspective view illustrating an embodiment of the present invention.

FIG. 4 is a perspective view showing a conventional example.

FIG. 5 is a perspective view illustrating a conventional example.

FIG. 6 is a perspective view illustrating a conventional example.

[Explanation of symbols]

 11 ... Lower conductor case 12 ... Dielectric substrate 13 ... Microstrip line 15 ... Upper conductor case 16 ... Screw 21 ... Conductive region 22 ... Through hole

Claims (1)

[Claims] 1. A dielectric substrate arranged on a lower conductor case, a microstrip line formed on the surface of the dielectric substrate, and a conductive layer formed on the surface of the dielectric substrate on which the microstrip line is formed. An area, a plurality of through holes formed in the conductive area at intervals less than 1/2 wavelength of a signal transmitted through the microstrip line, and a surface in contact with the through hole portion,
A high frequency circuit structure comprising: an upper conductor case arranged on the dielectric substrate; and fixing means for integrally fixing the lower conductor case, the dielectric substrate, and the upper conductor case.