JP4129194B2 - Coaxial connector for high frequency circuits - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coaxial connector for a high frequency circuit used for a communication transceiver or the like.
[0002]
[Prior art]
Conventionally, coaxial connectors for high-frequency circuits have been widely used in high-frequency equipment. For example, as seen in Japanese Patent Application Laid-Open No. 9-283962 (Patent Document 1), a substrate on which a microwave circuit is mounted is provided in a housing. It is also used in microwave devices.
[0003]
As described above, a conventional example of a connection structure of a coaxial connector connected to a high-frequency circuit formed on a substrate in a housing is shown in FIGS.
[0004]
In these drawings, 1 is a housing, 2 is a substrate, 3 is a ground conductor, 5 is an internal conductor, 6 is an external conductor, 8 is a flange, 9 is a set screw, 12 and 14 are coaxial connectors, and 15 is a male screw portion. Indicates.
[0005]
The coaxial connector 12 in FIG. 5 is a flange-type connector, and the outer conductor 6 is connected and fixed to the housing 1 by fastening a flange 8 formed integrally with the outer conductor 6 with a set screw 9. On the other hand, the internal conductor 5 and the transmission line wiring on the substrate 2 are connected by soldering.
[0006]
The coaxial connector 14 in FIG. 6 is a screw-in type connector. A male screw portion 14 is processed on the outer surface of the external conductor 6, and the external conductor connection is performed by screwing into the female screw portion processed in the housing 1. The inner conductor 5 is connected by soldering as described above.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-283963 [0008]
[Problems to be solved by the invention]
When connecting with the high frequency circuit in a housing | casing using the above conventional coaxial connectors, there existed the following problems.
[0009]
In the case of the connector connection of FIG. 5, the transmission line wiring on the board 2 and the inner conductor 5 of the coaxial connector 12 are directly connected by aerial wiring, but the ground conductor 3 and the outer conductor 6 of the board 2 are connected to the housing 1. Connection. Moreover, although the ground conductor 3 is directly fixed and connected to the housing 1, the housing 1 and the external conductor 6 are connected with the gap 13 therebetween as shown in the figure. This gap 13 is unavoidable in terms of machining accuracy, but its existence causes a problem in terms of high frequency. That is, since the gap 13 exists, impedance mismatch occurs, and a transmission loss (return loss) that cannot be ignored occurs.
[0010]
The transmission loss increases as the conduction distance from the ground conductor 3 of the substrate 2 to the tip of the external conductor 6 of the connector through the housing 1 increases, and the degree of mismatch increases. Also, this adverse effect becomes more prominent as the frequency is higher. Therefore, in order to reduce transmission loss at high frequencies, it is necessary to shorten the conduction distance through the housing 1, but the connection structure as shown in FIG. 5 cannot be shortened.
[0011]
On the other hand, in the case of the screw-type connection structure as shown in FIG. 6, the conduction distance is shorter than the former and transmission loss is reduced. However, when force is applied in the direction of loosening the screw, the connector rotates and is soldered. There is a risk of damaging the wiring pattern.
[0012]
The present invention has been made in view of the above problems, and an object of the present invention is a coaxial connector for a high-frequency circuit connected to a high-frequency transmission line formed on a substrate in a housing, having excellent matching and stability. It is to provide a connector that can be firmly connected.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, the present invention according to claim 1 is a coaxial connector for a high frequency circuit connected to a high frequency circuit formed on a substrate in a housing, comprising: a high frequency transmission line on the substrate; An internal conductor to be connected, a dielectric provided around the outside of the internal conductor, an external conductor provided around the outside of the dielectric, the external conductor, and a grounding conductor of a substrate in the enclosure A coaxial connector for a high-frequency circuit including a spring-like member connected to a contact surface provided on the body for short-circuiting , and the spring-like member is pressed against the front end surface of the external conductor. It is characterized by having an elastic part to be applied .
[0014]
According to a second aspect of the present invention, in the coaxial connector for a high frequency circuit according to the first aspect, the spring-like member is formed integrally with the outer conductor on a front end surface of the outer conductor. To do.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view and a front view of a first embodiment of a coaxial connector for a high-frequency circuit according to the present invention, and FIG. 2 is an explanatory view showing a state in which the coaxial connector of FIG. 1 is connected. In the figure, reference numeral 4 denotes a coaxial connector according to the present invention, and an outer conductor 6 is provided at its tip with an elastic part 7 having a divided tip, and the outer conductor is provided with a flange 8 having four mounting holes. Yes.
[0016]
As shown in FIG. 2, the outer conductor 6 of the coaxial connector 4 is inserted into an outer conductor connecting portion having a contact surface provided in the housing 1, and the tip of the elastic portion 7 is pressed against the corresponding contact surface, and the flange 8 is fixed to the housing 1 using a set screw 9.
[0017]
Since it is attached as described above, the outer conductor 6 of the connector 4 is directly and firmly connected to the housing 1, and at the same time, a connection with a short conduction distance is realized.
[0018]
Next, a second embodiment will be described. FIG. 3 is an explanatory diagram of a method for connecting coaxial connectors, and FIG. The coaxial connector according to this embodiment includes a flange-type coaxial connector main body 10 and a disc spring washer 11 of the same type as the conventional example of FIG.
[0019]
In the present embodiment, a Belleville spring washer 11 is inserted between the front end surface of the outer conductor 6 and the opposite surface of the housing 1 facing the outer conductor 6 as illustrated. The gap between the faces is set to be suitable for the spring washer 11, and the connector is attached by tightening the flange 8 with a set screw 9.
[0020]
Since it is attached as described above, the outer conductor 6 of the coaxial connector main body 10 is firmly connected to the housing 1 via the disc spring washer 11, and at the same time, a connection with a short conduction distance is realized. FIG. 7 shows the measurement results of the return loss between the coaxial connector (A) of the present invention shown in FIG. 4 and the coaxial connector (B) shown in FIG. FIG. 7 shows that the 1.0 to 1.5 dB characteristics are improved.
[0021]
【The invention's effect】
As described above, the present invention relates to a high-frequency circuit coaxial connector connected to a high-frequency circuit formed on a substrate in a housing. In addition to the normal configuration of the internal conductor, dielectric, and external conductor, the connector configuration is external. A spring-like member for short-circuiting the conductor and the ground conductor of the substrate in the housing via the housing, and when the coaxial connector of the present invention is connected to the housing side, the external conductor Is connected to the housing facing each other via a spring-like member with a short conduction distance, which can suppress the occurrence of impedance mismatch due to the presence of a gap as in the case of a coaxial connector with a conventional configuration. It is possible to realize a coaxial connector for a high-frequency circuit with excellent performance.
[0022]
The spring-shaped member can be realized by integrally forming the elastic portion at the tip of the outer conductor or using a disc spring washer, and can absorb expansion and contraction of the coaxial connector due to temperature change by the effect of the spring-shaped member, A stable connection is possible. In addition, an assembly process becomes simpler by integrally forming.
[0023]
Further, the configuration of the coaxial connector of the present invention can be realized by a flange type connection, not by a screw-in type, so there is no possibility of damage to the wiring pattern due to connector rotation, and a stable and strong connector connection can be obtained. .
[Brief description of the drawings]
FIG. 1 is a side view and a front view of a first embodiment of the present invention.
FIG. 2 is an explanatory diagram of a state in which the coaxial connector of FIG. 1 is connected.
FIG. 3 is an explanatory diagram of a connection method according to a second embodiment of this invention.
4 is an explanatory diagram of a state in which the coaxial connector of FIG. 3 is connected.
FIG. 5 is an explanatory view of a conventional coaxial connector connection structure.
FIG. 6 is an explanatory view of another conventional coaxial connector connection structure.
FIG. 7 is a diagram showing measurement results of return loss of the coaxial connector of the present invention and a conventional example.
[Explanation of symbols]
1: casing, 2: substrate, 3: ground conductor, 4: coaxial connector, 5: inner conductor, 6: outer conductor, 7: elastic part, 8: flange, 9: set screw, 10: coaxial connector body, 11 : Disc spring washer, 12: coaxial connector, 13: gap, 14: coaxial connector, 15: male thread

Claims (2)

A coaxial connector for a high-frequency circuit connected to a high-frequency circuit formed on a substrate in a housing, wherein the inner conductor is connected to a high-frequency transmission line on the substrate, and a dielectric is provided around the inner conductor. And an outer conductor provided on the outside of the dielectric, and a spring-like shape for connecting the outer conductor and the ground conductor of the substrate in the casing to a contact surface provided in the casing for short-circuiting. A coaxial connector for a high-frequency circuit, comprising: a spring-like member having an elastic portion that is pressed against the contact surface on a distal end surface of an outer conductor. . 2. The coaxial connector for a high frequency circuit according to claim 1, wherein the spring-like member is formed integrally with the outer conductor on a front end surface of the outer conductor .

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