JPH07226267A - Heat resistant coaxial connector for high frequency - Google Patents

Abstract

PURPOSE:To provide a coaxial connector whose insulator is not deteriorated even in high temperature environments and make it usable without degrading the high frequency properties. CONSTITUTION:A coaxial connector is composed of a cylindrical outer conductor 1, a center conductor 2 put in the inside of the outer conductor 1, and a pair of ceramic cylindrical insulating bodies 31, 32 which are put between the outer conductor 1 and the center conductor 2 and in which flanges 31a, 32a are formed in the end faces on the opposite to each other. The connector is made to have a structure in which the insulating bodies 31, 32 sandwich a flange 2a formed in the center conductor 2 from both sides, the outer diameter of the insulating bodies 31, 32 are made smaller than the inner diameter of the outer conductor 1, and an air layer 5 is formed between the insulating bodies 31, 32 and the outer conductor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency coaxial connector, and particularly to a high frequency transmission loss even in a high temperature environment.
The present invention relates to a heat-resistant high-frequency coaxial connector which has almost no performance deterioration such as characteristic impedance variation and can be used for transmitting and receiving high-frequency signals in a wide frequency band.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional high-frequency coaxial connector has a cylindrical outer conductor 11 and an outer conductor 11.
And a cylindrical insulator 13 for holding and fixing the central conductor 12 on the central axis of the outer conductor 11 while electrically insulating the central conductor 12 from the central conductor 12. . This insulator 13 is generally made of a synthetic resin material,
Especially when used in a high temperature environment, a synthetic resin material having excellent heat resistance such as polytetrafluoroethylene (PTFE) has been used. In the figure, reference numeral 12a is a contact piece for receiving and connecting a pin-shaped contactor (center conductor) of a mating connector (not shown), and 14 is a fitting portion for fitting and contacting the outer conductor of the mating connector. Is.

In this conventional high-frequency coaxial connector, a heat-resistant synthetic resin material such as PTEF is used as an insulator for those used in a high temperature environment. There is a problem that the resin softens when the temperature approaches 200 ° C., and melts when the temperature rises further, and the resin does not function as an insulator. Therefore, the conventional high-frequency coaxial connector cannot be used in a temperature environment of 200 ° C. or higher. In addition, the conventional high-frequency coaxial connector has a characteristic that the relative permittivity of the insulator fluctuates greatly under a constant high temperature even if the insulator does not soften or melt. There is also a problem that it has a bad influence such as a change in impedance and an accompanying increase in transmission loss, so that it cannot be used as a connector.

Therefore, in Japanese Patent Laid-Open No. 2-31084, an insulator is formed of a low dielectric constant type ceramics, and an outer conductor and a center conductor are thin films made of a conductive material such as silver, copper or gold. Formed coaxial connectors have been proposed.

[0005]

However, in the coaxial connector described in Japanese Patent Laid-Open No. 2-31084, the insulator is arranged in close contact with the outer conductor and the center conductor, so that the environmental temperature rises. In this case, similarly to the conventional high-frequency coaxial connector, there still remains a problem that the high-frequency characteristics of the connector are impaired due to the fluctuation of the relative permittivity of the insulator.

The present invention has been proposed in order to solve the problems of each of the conventional techniques described above, and the insulator does not deteriorate even in a high temperature environment and the high frequency characteristics are not impaired. The purpose is to provide a heat-resistant high-frequency coaxial connector that can be used.

[0007]

In order to achieve the above object, a heat-resistant high-frequency coaxial connector of the present invention comprises a cylindrical outer conductor, a center conductor arranged on the central axis of the outer conductor,
A coaxial connector which is interposed between the outer conductor and the center conductor, and which has a cylindrical insulator for holding the center conductor in a state of being electrically insulated on the center axis of the outer conductor. It is made of ceramics, and an air layer is provided between the insulator and the outer conductor, and preferably, a flange is provided substantially at the center of the central conductor in the axial direction, and the insulator is provided on both sides of the flange. A pair of insulators sandwiched from each other, and flanges are respectively provided on the opposing end surfaces, and a step portion with which one flange of the pair of insulators is locked is provided on the inner circumference of the outer conductor, and the other The structure is provided with a fixing ring for fixing the flange. More preferably, the outer diameter of a portion of the pair of insulators excluding the flange is formed to be smaller than the inner diameter of the outer conductor, and the outer diameter of the flange of the center conductor is the outer conductor. It is configured to be smaller than the inner diameter. Further, a flange is provided on the outer circumference of the outer conductor if necessary.

[0008]

According to the heat-resistant high-frequency coaxial connector of the present invention having the above structure, the use of ceramics as the insulator prevents the insulator from being deteriorated even in a high temperature environment.
In addition, by providing an air layer between the outer conductor and the insulator, fluctuations in the voltage standing wave ratio (VSWR) of the connector can be suppressed even when the relative permittivity of the insulator changes with the rise in environmental temperature. be able to. Furthermore, the air layer can reduce heat conduction from the outside to the inside of the connector.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the heat resistant high frequency coaxial connector of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional view of one embodiment of the heat resistant high frequency coaxial connector of the present invention. The connector shown in the figure has a cylindrical outer conductor 1, a central conductor 2 disposed on the central axis inside the outer conductor 1, and an interposing between the outer conductor 1 and the central conductor 2. It is provided with a pair of insulators 31 and 32 for holding the central conductor 2 from the outside and fixing it in the outer conductor 1.

As shown in the figure, two steps 1a and 1b are provided on the inner periphery of the outer conductor 1, and the outer conductor 1 has three different inner diameters of small diameter, medium diameter and large diameter. Has a diameter. The central conductor 2 has a flange 2a approximately at the center in the axial direction.
The center conductor 2 and the flange 2a are formed such that their outer diameters do not contact the inner circumference of the outer conductor 1.

The pair of insulators 31 and 32 are a combination of two of the same shape, which are formed in a cylindrical shape from heat-resistant ceramics having electrical insulation and excellent high frequency characteristics, and are opposed to each other. The end faces have flanges 31a, 3 respectively.
2a is provided. The cylinder inner diameters of the insulators 31 and 32 are
The diameter is slightly larger than the outer diameter of the center conductor 2 so that the center conductor 2 can be loosely fitted. In addition, this insulator 31, 32
The outer diameters of the flanges 31a and 32a are formed to be substantially the same as the middle diameter portion of the outer conductor 1, and at the same time, the outer diameters of the other portions are formed so as not to contact the inner circumference of the outer conductor 1. I am doing it.

Reference numeral 4 denotes a fixed ring having an outer diameter that can be press-fitted into a large diameter portion of the inner circumference of the outer conductor 1, and has an inner diameter larger than the outer diameters of the insulators 31 and 32. Further, the wall thickness of the ring 4 is thicker than the width of the step portion 1b of the outer conductor 1.

Reference numeral 20 denotes a mating connector which is fitted with an external contact body 21 which fits and contacts the outer periphery of the end portion of the outer conductor 1, and a contact 22 which is inserted into and contacts the center conductor 2. In order to facilitate and ensure the fitting and connection with the mating connector 20, in the present embodiment, a predetermined length is set in the axial direction from the end of the outer conductor 1 on the side to be fitted with the external contact body 21. A slit is formed as much as the outer conductor 1
The diameter of the slit-formed portion is slightly larger than the outer diameter of the fixed ring 4, and the diameter of the outer conductor 1 is slightly larger than the outer diameter of the outer contact body 21. Is provided. The center conductor 2 also has an inner diameter that is slightly smaller than the outer diameter of the contact 22, and, like the outer conductor 1, is provided with a slit for a predetermined length in the axial direction from the end. As a result, the outer conductor 1 and the central conductor 2, and the outer contact body 21 and the contactor 22 are in spring contact with each other.

In assembling the heat-resistant high-frequency coaxial connector of this embodiment having the above-mentioned structure, first, the insulators 31 and 32 are provided from both ends of the center conductor 2 and the flanges 31a and 31a.
The end faces provided with 32a are inserted so as to face each other, and the flange 2a of the center conductor 2 is sandwiched. In this state, insulators 31, 32
Is inserted inside from the large diameter side of the outer conductor 1, and the flange 31
a is locked to the step portion 1a. As illustrated, the thickness of the flange 2a of the central conductor 2 and the flanges 31a and 32a of the insulators 31 and 32 and the inner circumference of the outer conductor 1 so that the step portion 1b and the flange 32a are flush with each other in this state. It is formed so that the axial length of the medium diameter portion is the same. Next, the fixing ring 4 is press-fitted from the large diameter side of the outer conductor 1 and brought into contact with the step portion 1b and the flange 32a.

As a result, the center conductor 2 and the insulator 3
1, 32 are firmly held and fixed inside the outer conductor 1 by the fixing ring 4, and the flanges 31a and 32a are in contact with the medium diameter portion of the outer conductor 1, and the insulator 3
An air layer 5 is formed between 1, 32 and the outer conductor 1 over the entire axial length.

According to the connector thus configured, the insulators 31 and 3 are used even when used in a high temperature environment.
Since 2 is made of ceramics, physical deterioration is eliminated, and at the same time, since the air layer 5 is formed between the outer conductor 1 and the insulators 31 and 32, the relative permittivity of the insulators 31 and 32 is high. Even if the temperature rises due to, the fluctuation in the composite relative permittivity of the insulators 31 and 32 and the air layer 5 can be suppressed to a small level, and as a result, the fluctuation in the characteristic impedance of the connector can be reduced, and the VSWR accompanying this can be reduced. The fluctuation of can be suppressed.

Here, the insulators 31 and 32 and the air layer 5 are
The dimensions and shape of each part of the connector are designed and formed in advance so that the combined relative permittivity of and becomes almost constant over the entire length of the connector. In addition, the provision of the air layer 5 has an effect of reducing heat conduction from the outside to the inside of the connector. Further, since the center conductor 2 is loosely fitted to the insulators 31 and 32, it is in a floating state, and when fitted to the mating connector 20, even if the centers of both are slightly displaced, The center conductor 2 moves in the radial direction and can be fitted securely, and since the outer conductor 1 and the center conductor 2 are in spring contact with the outer contact body 21 and the contact 22, respectively, there is no contact failure.

The heat-resistant high-frequency coaxial connector of the present invention is not limited to the above-mentioned embodiments, but various modifications can be made within the scope of the invention. For example, a flange may be formed on the outer periphery of the outer conductor 1 as shown in FIG. 1 for attachment to various devices. Although the outer conductor 1 and the insulators 31 and 32 have a cylindrical shape in the above-described embodiments, they may have a rectangular tube shape or an elliptic tube shape. The air layer 5 can be sized according to the ambient temperature or the like to be used by changing the dimensions of the outer conductor 1 or the insulators 31, 32.

[0019]

As described above, the heat-resistant high-frequency coaxial connector of the present invention can be used even in a high temperature environment without deterioration of the insulator and loss of high-frequency characteristics.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of one embodiment of a heat resistant high frequency coaxial connector of the present invention.

FIG. 2 shows a cross-sectional view of a conventional high frequency coaxial connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Outer conductor 2 ... Center conductor 2a ... Flange 4 ... Fixing ring 5 ... Air layer 11 ... Conventional outer conductor 12 ... Conventional center conductor 12a ... Contact piece 13 ... Conventional insulator 14 ... Fitting part 20 ... Mating side Connector 21 ... External contact 22 ... Contact 31 ... Insulator 31a ... Flange 32 ... Insulator 32a ... Flange

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Hanafusa 3-20-4 Nishishimbashi, Minato-ku, Tokyo Inside NEC Engineering Co., Ltd. (72) Inventor Tatsuo Kano 1-21-6 Dogenzaka, Shibuya-ku, Tokyo Japan Aviation Electronics Industry Co., Ltd.

Claims (5)

[Claims] 1. A tubular outer conductor, a center conductor disposed on the center axis of the outer conductor, and a center conductor disposed between the outer conductor and the center conductor so that the center conductor is disposed on the center axis of the outer conductor. A coaxial connector comprising a tubular insulator that is held in an electrically insulated state, wherein the insulator is made of ceramics, and an air layer is provided between the insulator and the outer conductor. A heat-resistant high-frequency coaxial connector characterized by the following. 2. A flange is provided substantially at the center of the center conductor in the axial direction, the insulator is a pair of insulators sandwiching the flange from both sides, and flanges are provided on opposite end faces, respectively. 2. The heat-resistant high-frequency coaxial connector according to claim 1, further comprising a step portion provided on an inner circumference of the conductor to which one flange of the pair of insulators is locked, and a fixing ring for fixing the other flange. 3. The heat-resistant high-frequency coaxial connector according to claim 2, wherein the outer diameter of the portion of the pair of insulators excluding the flange is smaller than the inner diameter of the outer conductor. 4. The heat-resistant high-frequency coaxial connector according to claim 2, wherein the outer diameter of the flange of the central conductor is smaller than the inner diameter of the outer conductor. 5. The heat-resistant high-frequency coaxial connector according to claim 1, 2, 3 or 4, wherein a flange is provided on the outer periphery of the outer conductor.