JP2002373743A - Coaxial connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coaxial connector capable of eliminating a dispersion in the connector characteristics and suppressing the cost as improvement of the conventional technique which requires the connector center pin mounting works to a coaxial cable core conductor when the coaxial connector is to be mounted on a coaxial cable and which generally requires a connector mounting accuracy corresponding to high frequencies. SOLUTION: The coaxial connector is composed of the coaxial cable consisting of the core conductor, coaxial insulating material arranged so as to surround the core conductor and an outer conductor arranged in such a way as surrounding the insulating material, the center pin attached to the core conductor, a connector body, and a center pin insulation located between the center pin and connector body, wherein the forefront of the core conductor inside the coaxial cable is located inside the cut surface of the coaxial cable outer conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial connector used for connection between a coaxial cable for transmitting high-frequency signals and high-speed digital signals, or between a coaxial cable and a high-frequency device or between a high-frequency device and a high-frequency device.

[0002]

2. Description of the Related Art Conventionally, a coaxial connector has been used as one of connecting means of a coaxial cable for electrically realizing high-frequency signal and high-speed digital signal transmission. This coaxial connector is usually a male-female pair attached to one end of a coaxial cable or an input / output port of a high-frequency device. In particular, in the case of a coaxial cable, the outer conductor of the cable is assembled by soldering the connector body and the core wire of the cable to the center pin of the connector. The assembling of this part will be described using a case where a 40 GHz band high frequency connector is attached to a semi-rigid coaxial cable as an example.

First, a coaxial cable (diameter: 3 mm) is passed through a cylindrical part called a sleeve and soldered by a method such as heating on a hot plate (step 1). Next, remove the outer conductor and coaxial insulator of the coaxial cable from the cable cross section to the position of the sleeve (about 5 mm)
(Step 2). At this time, the core of the cable is left.

Next, the length of the exposed core wire is adjusted using a jig for determining the length of the core wire (1.27 ± 0.127 m).
m) (Step 3). Subsequently, the center pin of the coaxial connector is attached to the exposed portion by soldering (Step 4). Finally, the connector body is attached to the sleeve portion to complete the connector (Step 5).

[0005]

However, according to the prior art, when such a coaxial connector is mounted, the outer conductor and the coaxial insulator of the coaxial cable are removed in the above-mentioned step 2, and the core conductor is removed in the step 3. It was necessary to perform a complicated operation of cutting the length to within a predetermined tolerance and soldering the center pin of the connector.

In the case of a coaxial cable used in a high frequency range of several tens of GHz or more, the diameter of the coaxial insulator / core conductor is set to an extremely small value in order to prevent generation of an unnecessary electromagnetic wave mode in the cable. . For example, in the case of a 40 GHz band coaxial cable, the core wire has a diameter of 300 μm. In the process described above, it is necessary to attach the center pin of the connector to such a core wire, and the high frequency characteristics of the completed connector are greatly affected by the accuracy of the attachment position and the presence or absence of small metal chips generated during the attachment processing. There was a problem.

Accordingly, the present invention provides a coaxial connector for a high-frequency circuit, which does not require complicated termination of the coaxial cable at the time of assembling the connector, and reduces the deterioration of the high-frequency characteristics of the connector which depends on the processing accuracy at the time of mounting. It is intended to provide a new connector structure.

[0008]

The invention according to claim 1 is
A coaxial cable composed of a core conductor and a coaxial insulating material arranged so as to surround the core conductor, and an outer conductor arranged so as to surround the insulating material; a center pin attached to the core conductor; and a connector body. In a coaxial connector including, as a component, the center pin and a center pin insulator located between the connector main body, the tip of the core wire conductor inside the coaxial cable is closer to the coaxial cable inner side than the cut surface of the coaxial cable outer conductor. It is characterized by something.

According to a second aspect of the present invention, in the coaxial connector according to the first aspect, at least a part of the center pin insulator is cylindrical, and an outer diameter thereof is smaller than an inner diameter of the outer conductor of the coaxial cable. This part is inserted simultaneously with the center pin inside the coaxial cable.

According to a third aspect of the present invention, in the coaxial connector according to the second aspect, the dimension of the shape of the center pin insulator other than the portion inserted into the coaxial cable is larger than the inner diameter of the outer conductor of the coaxial cable. When inserting this center pin insulator into a coaxial cable, the portion where this dimension becomes large contacts the outer conductor of the coaxial cable, thereby positioning the length of the center pin insulator inserted into the coaxial cable. It is characterized by performing.

According to a fourth aspect of the present invention, in the coaxial connector according to the third aspect, a helically processed sleeve is fixedly attached so as to surround the outer conductor of the coaxial cable, and the connector is attached to the sleeve. When the main body is attached, the center pin insulator is simultaneously pressed into the coaxial cable, and the core conductor of the coaxial cable is inserted into the center pin fixedly attached to the center pin insulator to establish connection. It is characterized by being performed.

[0012]

FIG. 1 shows a preferred embodiment of the present invention.
3 to FIG.

FIG. 1 is an internal structural view of the present coaxial connector (female type). (1) is a core conductor of a coaxial cable, and a coaxial insulating material (2) and an outer conductor (3) are arranged so as to surround the core conductor, and a coaxial cable is constituted by (1), (2) and (3). I have. In the case of a semi-rigid cable, the core conductor (1) and the outer conductor (3) of the coaxial cable are usually made of copper or copper plated with tin. As the coaxial insulating material, Teflon (registered trademark) or micropolar steflon is used. The center pin (4) is attached to the tip of this coaxial cable.
And a center pin insulator (6). The center pin has a hollow structure, and a core conductor of a coaxial cable is inserted into one end of the center pin. The other end is provided with a notch so as to easily receive the center pin of another coaxial connector (male type) not shown. As such a material of the center pin, beryllium copper plated with gold of about 3 μm is preferable. Also, as shown in the figure, a part of the center pin conductor is inserted inside the outer conductor of the coaxial cable. A sleeve (7) having a cylindrical shape and subjected to spiral processing is fixed to the outer conductor of the coaxial cable using solder (8). The material of the sleeve (7) can be gold-plated beryllium copper or gold-plated copper as in the case of the center pin (4). The connector body (5) is screwed into the sleeve (7). The center pin insulator (6) is fixed between the inner inner wall of the connector body (5) and the outer conductor (3) of the coaxial cable so as to be sandwiched therebetween. The center pin (4) and the center pin insulator (6) are fixed.

FIG. 2 is an assembly view of the coaxial connector shown in FIG.

FIG. 2A is a sectional view of the cut coaxial cable. The coaxial cable includes a core conductor (9), a coaxial insulating material (10), and an outer conductor (11).

FIG. 2B shows a process of attaching the sleeve (12). Insert the coaxial cable into the sleeve and heat it up to around 200 ° C with a hot plate etc.
Fix the coaxial cable and the sleeve using 3).

FIG. 2 (c) shows a terminal processing step of the coaxial insulator of the coaxial cable. Using the terminal processing jig (14),
The coaxial insulator of the coaxial cable is pushed from the end of the cable by the length that the center pin insulator is inserted into the outer conductor.

FIG. 2D is a view showing how the center pin (15), the center pin insulator (16) and the connector body are mounted. First, a very small amount of solder (18) is attached to the core conductor of the coaxial cable so as not to hinder insertion into the center pin. Next, the center pin (15) and the center pin insulator (16) fixed to the center pin (15) are attached so that the core conductor of the coaxial cable is inserted into the cavity of the center pin (15). Further, the connector body (17) is attached from the outside of the connector body (17) by using a spiral formed on the sleeve (12).

FIG. 2E is a final assembly diagram. By heating the connector assembled in the process up to FIG. 2D on a hot plate, the center pin (15) is heated.
And the core conductor (9) of the coaxial cable are soldered,
Stable electrical conduction is ensured. Although not shown, in order to obtain more stable electrical characteristics, the connector body (1
7) and the sleeve (12) may be soldered.

Next, FIG. 3 shows the high frequency characteristics of the coaxial connector having the new structure invented in the present invention. The results were obtained by attaching two coaxial connectors of the present invention to a semi-rigid cable having a length of 40 cm and a diameter of 3 mm, and measuring the reflection and transmission characteristics using a vector network analyzer. FIG.
As can be seen from (a), this coaxial connector has a frequency of 20 GHz
It shows a return loss of about 25 dB below and about 15 dB below 40 GHz, indicating good impedance matching in connection with a coaxial cable. Also, 40 cm from Fig. 3 (b)
When using long semi-rigid cables, the signal loss is
It can be seen that it has good signal propagation characteristics at 3 dB or less for a signal of 40 GHz.

Incidentally, in addition to the method disclosed in the present embodiment,
It is also possible to adopt a configuration in which the center pin is male.
Further, in the present embodiment, the spiral processing is performed on the sleeve portion. Alternatively, a spiral processed directly on the outer conductor of the coaxial cable may be used. Also, a second helically processed sleeve different from that shown in the present embodiment is used, and the first sleeve (in this case, not helically processed) is sandwiched between the second sleeve and the connector body. The connector may be fixed in this manner. Further, the coaxial cable to which the connector is fixed does not necessarily need to be semi-rigid, and can be applied to a flexible or rigid type coaxial cable. Also, the coaxial cable to which the connector is fixed does not necessarily have to have a coaxial insulator, and can be applied to a hollow line such as an air suspended line.

[0022]

As is apparent from the above description, the connection point between the center pin of the connector and the core conductor of the coaxial cable is located closer to the cable than the outer conductor of the coaxial cable. The processing of the core conductor of the cable, that is, the work of removing the outer conductor / coaxial insulator and the work of attaching the center conductor becomes unnecessary, and the work of attaching the high-frequency connector to the coaxial cable is greatly simplified.

In addition, since the process is simple, even a beginner can easily perform a connector mounting operation requiring skill in the conventional method, and it is possible to stably obtain high-frequency characteristics of a finished product.

[Brief description of the drawings]

FIG. 1 is a sectional view of a coaxial connector of the present invention.

FIG. 2 is a diagram illustrating an assembly process of the coaxial connector of the present invention.

FIG. 3 is a diagram showing high frequency characteristics of a coaxial cable to which the coaxial connector of the present invention is attached.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 core conductor 2 coaxial insulating material 3 outer conductor 4 center pin 5 connector body 6 center pin insulator 7 sleeve 8 solder core conductor 10 coaxial insulating material 11 outer conductor 12 sleeve 13 ... Solder 14 ... Terminal treatment jig 15 ... Center pin 16 ... Center pin insulator 17 ... Connector body 18 ... Solder

Claims (4)

[Claims] 1. A coaxial cable comprising a core conductor, a coaxial insulating material arranged so as to surround the core conductor, and an outer conductor arranged so as to surround the insulating material, and a center attached to the core conductor. In a coaxial connector including, as constituent parts, a pin, a connector body, and a center pin insulator located between the center pin and the connector body, the tip of a core conductor inside the coaxial cable is larger than a cut surface of the outer conductor of the coaxial cable. A coaxial connector characterized by being inside a coaxial cable. 2. The coaxial connector according to claim 1, wherein at least a part of the center pin insulator is cylindrical, and an outer diameter thereof is smaller than an inner diameter of the coaxial cable outer conductor.
A coaxial connector characterized in that this part is inserted into the coaxial cable at the same time as the center pin. 3. The coaxial connector according to claim 2, wherein the dimension of the shape of the center pin insulator other than the portion inserted into the coaxial cable is larger than the inner diameter of the outer conductor of the coaxial cable, and When the body is inserted into the coaxial cable, the length of the center pin insulator inserted into the coaxial cable is determined by contacting the part where this dimension increases to the outer conductor of the coaxial cable. Coaxial connector. 4. The coaxial connector according to claim 3, wherein a sleeve which is spirally wound so as to surround the outer conductor of the coaxial cable is fixedly attached, and when the connector body is attached to the sleeve, The center pin insulator is simultaneously pressed into the coaxial cable, and the connection is performed by inserting the core conductor of the coaxial cable into the center pin fixedly attached to the center pin insulator. Coaxial connector.