JPH0310401A - Structure for preventing resonance of case - Google Patents

Abstract

PURPOSE:To suppress the undesired resonance of a case without reducing the high Q of the circuit by providing a gap between an upper ridge of a barrier and an upper face of a case so that the range of the resonance of the case is expanded from one case part to other case part and providing a radio wave absorbing body or a resonance frequency adjustment screw to the inner face of the other case part. CONSTITUTION:An oscillation circuit 55 and an amplifier circuit 56 are separated by a barrier 2 made of a copper alloy material placed upright to a bottom face 14 of a case 1 and the mount space is shielded and separated except the butt connection of a microstrip line. The upper ridge 21 of the barrier 2 is not in contact with the upper face 13 of the case being the inner face of the fixed cover 6 (61) but has a prescribed gap for coupling a microwave and the resonance range of the case is expanded to case parts A11, B12 through the gap. Moreover, a radio wave absorbing body 3 or a frequency adjustment screw 4 is provided onto the inner face of the case part B12. Thus, the undesired case resonance is suppressed without reducing the high Q of the circuit.

Description

[Detailed Description of the Invention] [Summary] Regarding a housing resonance prevention structure in a microwave unit configured with a microwave integrated circuit, we have developed a structure that suppresses unnecessary housing resonance without reducing the high Q of the circuit. For the purpose of providing, a circuit H consisting of a microwave integrated circuit and having a high Q is fixedly housed in a casing part A separated by a partition wall vertically provided on the bottom of the casing, and In a microwave unit that accommodates a low-Q circuit in another adjacent housing part B, the area of housing resonance due to the circuit H is
A gap is provided between the upper edge of the partition wall and the upper surface of the housing so that it extends to the housing part B as well as the housing part, and a radio wave absorber or a resonance frequency adjustment screw is installed on the inner surface of the housing part B. The system is configured to provide the following.

[Industrial application field]

The present invention relates to a housing resonance prevention structure in a microwave band to millimeter wave band (simply referred to as microwave) unit configured with a microwave integrated circuit (hereinafter abbreviated as MIC).

As electronic components become smaller and have higher performance, MICs are frequently used in microwave circuit configurations, and the miniaturization and higher frequency of devices are rapidly promoted.

A MIC is provided for each circuit, and multiple related circuits are collectively mounted in one housing to form a unit for maintenance handling, aiming for compactness, high performance, and economy.

For collective implementation of MICs within this unit, each M
It is required that the IC exhibit the expected performance and that no characteristic interference occurs between the MIC circuits.

[Conventional technology]

FIG. 4(a) shows an internal plan view of an example of a conventional unit, and FIG. 4(a) shows a sectional view of the same side.

One conventional example is an oscillator unit that accommodates an oscillation circuit 55 of the old C configuration having a dielectric resonator 59 and an amplifier circuit 56 of one IC configuration that amplifies its output, as shown in FIG.

The unit structure is composed of a casing 15 with an open top surface and a lid 6 that shields the top surface of the opening. Each MrC board of an oscillation circuit 55 and an amplifier circuit 56 is tightly fixed to the bottom surface 16 of the casing 15. The ends of the strip lines are butted together, conductor connections are made to connect the circuits, and the amplifier circuit 56 is connected.
The output is connected to a connector provided on the side surface of the housing 15.

Here, the oscillation circuit 55 and the amplifier circuit 56 are partitioned by a partition wall 25 provided vertically on the bottom surface 16 of the housing 15, and are shielded except for the abutment connection portion of the microstrip line, thereby dividing the mounting space.

[Problem to be solved by the invention]

However, (1) Due to the volume of the casing of the oscillation circuit 55, casing resonance may occur at frequencies near the operating frequency.

■ In this case, it is necessary to suppress the housing resonance, and for this reason, a radio wave absorber 35 made of ferrite-mixed rubber material, etc.
is adhesively fixed on the inner wall of the casing of the oscillation circuit 55 at a position where the absorption effect is enhanced to suppress absorption.

(2) However, if the radio wave absorber 35 is installed close to the dielectric resonator 59, the high Q of the oscillation circuit 55 will be lowered.

There are other problems.

In view of these problems, it is an object of the present invention to provide a structure that suppresses unnecessary casing resonance without reducing the high Q of the circuit.

[Means to solve the problem]

The above problem is solved by installing a circuit H51 with a high Q of a microwave integrated circuit in the housing section All, which is divided by the partition wall 2 vertically installed on the bottom surface 14 of the housing L, as shown in FIG. In a microwave unit that is fixedly housed on the bottom surface 14 and houses a low-Q circuit L52 in another adjacent housing part B12, the area of housing resonance due to the circuit H51 is in the housing part All. In addition, housing part B12
The upper edge 21 of the partition wall 2 and the upper surface 13 of the casing
This problem is solved by the housing resonance prevention structure of the present invention, in which a gap is provided between the housing part B12 and a radio wave absorber 3 or a frequency adjustment screw 4 is provided on the inner surface of the housing part B12.

(Function) FIG. 1 shows a side sectional view of the unit of the present invention, and FIG. 5 shows an example of Q reduction characteristics.

That is, as shown in FIG. 1, the housing section All housing the circuit H51 with a high circuit Q is connected to the partition wall 2 as in the prior art example described above.
The housing resonance mode in a completely shielded state where the upper edge 21 is electrically connected to the housing top surface 13, and the housing resonance when the housing part B12 is also included in the housing resonance area by providing a gap according to the present invention. It is clearly different from the mode, and when a gap is provided, the casing resonance situation (presence or absence of resonance, resonant frequency) depends on the casing situation (size, shape, presence or absence of a radio wave absorber) of the casing part B12. changes.

On the other hand, in the case All, the circuit H51 with a high Q is used, but even if the upper side of the partition wall 2 is open, approximately Q is determined by the situation of the room inside the case All. No matter what happens to the housing section B12 on the other side, it will not be affected much and the Q will not drop.

Therefore, if the radio wave absorber 3 is placed in the casing part B12, the Q of the resonant circuit in the casing part All will not decrease;
- It is possible to suppress the casing resonance determined by both the casing parts 12.

Also, instead of the radio wave absorber 3, adjust the resonance frequency! ;4
It is also possible to suppress the influence of the housing resonance to a negligible level by providing and adjusting it in the housing part B12.

This resonant frequency adjustment screw 4 is, for example, a metal screw installed vertically on the wall in the same direction as the electric field, and by adjusting its length, the resonant mode can be shifted in a direction that has no influence.

Further, even if the resonance frequency adjustment screw 4 lowers the high Q of the component, it does not affect the high Q circuit H51 of the housing section All, as in the case of the resonance absorber 3.

In addition, in the circuit L52 where the radio wave absorber 3 or the resonance frequency adjustment screw 4 is attached, the Q of the circuit naturally decreases, but it is originally low (
, Q will not be a problem if it is a circuit that does not matter.

In this way, it is possible to provide a method for suppressing unnecessary housing resonance without reducing the high Q of the circuit.

〔Example〕

The present invention will be specifically described below with reference to embodiments shown in the drawings. The same reference numerals indicate the same objects throughout the figures. FIG. 2 shows a perspective view of the structure of a first embodiment of the invention, and FIG. 3 shows a side sectional view of a second embodiment of the invention.

Both of the present embodiments accommodate an MIC-configured oscillation circuit 55 having a high-Q dielectric resonator 59 and a MIC-configured low-Q amplifier circuit 56 that amplifies the output, the same as in the conventional example described above. It is an oscillator unit.

The first embodiment uses a radio wave absorber 3, and the second embodiment uses a resonant frequency adjustment spring 4.

The unit structure consists of a copper alloy casing with an open top,
Consisting of a lid 6.61 of the same village that shields the top surface of the opening,
Each old C board of the oscillation circuit 55 and amplifier circuit 56 is installed in the housing 1.
The end of the microstrip line is brought into contact with the bottom surface 14 of the housing 1, and the conductor connection is made to connect the circuits, and the output of the amplifier circuit 56 is connected to the connector provided on the side surface of the housing 1. .

Here, the oscillation circuit 55 and the amplifier circuit 56 are separated by a partition wall 2 made of a copper alloy material that is vertically installed on the bottom surface 14 of the casing 1, and are shielded except for the butt connection portion of the microstrip line to separate the mounting space. It is.

The upper edge 21 of this partition wall 2 does not come in contact with the top surface 13 of the casing on the inside surface of the fixed lid 6.61, leaving a predetermined gap wide enough to allow microwave coupling. Body resonance passes through this gap between the housing portion A11 and the housing portion B12.
The area will be expanded and carried out.

Further, in the first embodiment, as shown in FIG. 2, the radio wave absorber 3 made of a ferrite-mixed rubber material is adhesively fixed to a position of the expanded housing portion B12 where the absorption effect is large.

In the second embodiment, as shown in FIG.
In the region 2, a thin housing resonance frequency adjustment screw 4 is screwed vertically into the position where the adjustment effect is large, and by adjusting the screw length, the housing resonance mode is adjusted to a frequency that has no effect. I'll shift it.

The above embodiment shows an example, and the circuit H51 and the circuit L52 are not limited to an oscillation circuit and an amplifier circuit, and any combination of a high Q circuit and a low Q circuit may be used.
A combination of a filter circuit, a discriminator circuit, a high Q circuit, a multiplier circuit, a frequency divider circuit, etc., may be used as a low Q circuit.

Moreover, the materials of each part are not limited to those mentioned above.

(Effects of the invention) As described above, this embodiment has been implemented in the 8 GHz band, and good results have been obtained. Q of
A method for suppressing unnecessary casing resonance without reducing the oscillation is obtained, and the effect is remarkable.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of the unit of the present invention, Fig. 2 is a perspective view of the structure of the first embodiment of the invention, Fig. 3 is a side sectional view of the second embodiment of the invention, and Fig. 4 is a conventional FIG. 5 shows an example of the Q decreasing characteristic of an example unit. In the figure, 1.15 is the housing, 2.25 is the bulkhead, 3.35 is the radio wave absorber, 4 is the resonance frequency adjustment screw, 6.61 is the lid, 11 is the housing part A, and 12 is the housing part B. ,
13 is the top surface, 14.16 is the bottom surface, 21 is the top edge, 51 is the circuit H1
52 is a circuit, 55 is an oscillation circuit, 56 is an amplifier circuit, and 59 is a dielectric resonator. Mizuki Akira's Second Daishiza 1f) Yai I Cross-sectional view No. 3 Zuunilt's eugenic surface drawing No. 1 Figure 11 ) Infield floor plan 4 cut section fl An example of conventional unit-to-broom 4 Figure

Claims (1)

[Claims] A high Q circuit constituted by a microwave integrated circuit is installed in the housing part A (11) separated by a partition wall (2) vertically installed on the bottom surface (14) in the housing (1). H (51), the bottom surface (1
4) and housed in the other adjacent housing part B (12).
), the area of casing resonance due to the circuit H (51) is located in the casing portion A.
In addition to (11), a gap is provided between the upper edge (21) of the partition wall (2) and the upper surface of the housing (13) so as to extend to the housing part B(12). ) A housing resonance prevention structure characterized in that a radio wave absorber (3) or a resonance frequency adjustment screw (4) is provided on the inner surface of the housing.