JPS5936007Y2 - Rod antenna with capacitance forming device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a capacitance forming device for use in electronic equipment, devices, etc., and in particular, a rod antenna having a capacitance forming device used in electronic devices such as receivers that require an external antenna terminal. It is related to.

Conventionally, in shortwave and other receivers equipped with rod antennas, an external antenna has been used to further increase sensitivity.

For this reason, electronic devices and the like have been provided with a separate dedicated terminal for attaching an external antenna.

However, as devices become smaller, it has become difficult to provide a space for installing an external antenna terminal due to design considerations.

The present invention provides a means for solving such design problems, and will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a main part showing an example of a rod antenna having a capacitance forming device according to the present invention.

Reference numeral 1 denotes a metal connection body, which has tapered flange portions 2 at both ends of a cylindrical body, and each of the flange portions 2 communicates with each other through a through hole.

The metal rod 3 is inserted into the through hole from one flange portion 2□.

A threaded portion 4 is provided at one end of this metal rod 3, and an opposing metal body 5 is provided at the other end.

Further, the other flange portion 2□ is provided with an opposing metal body 5□ having a through screw hole.

A tip threaded portion 6 formed on the innermost element of a rod antenna to which a plurality of elements are concentrically and extendably attached is screwed into this through-screw hole.

Further, a washer 7 made of polyethylene is interposed between each of the opposed metal bodies 5□ and the flanges 2 and 2□.

Further, since the diameter of the metal rod 3 is smaller than the diameter of the through hole, a gap 8 is formed around the metal connection body 1 and the metal rod 3.

With this structure, the rod antenna provided on the main body of the device and the opposing metal bodies 5□ and 5□ are electrically connected.

The polyethylene washer 7 and the cavity 8 generate an external capacitance corresponding to the antenna equivalent capacitance.

Further, the elasticity of polyethylene itself ensures stronger tightening of the metal connecting body 1 and the opposing metal body.

This washer 7 does not need to be made of polyethylene;
Any other material with insulation, dielectricity, and elasticity, such as nylon, can be used, and its thickness and diameter may be determined depending on the design and the required external capacitance.

An external antenna lead wire 9 is wound around the metal connecting body 1 as shown in FIG. 2, or the end of the external antenna lead wire is joined to an alligator clip, and the clip is engaged with the cylindrical body.

In this way, the wound lead wire 9 becomes difficult to come off due to the flange portion 5.

In addition, there is a counter electrode (metallic body) on the inside of the cylindrical body and on both flanges.
Since the electrode area can be increased, the capacitance can also be relatively increased.

Therefore, the signal that has entered the external antenna lead wire 9 is introduced into the rod antenna via this capacitance, and is further introduced into the antenna circuit in the receiver connected to the rod antenna. Prevented.

Further, this capacitance can be used to compensate for a decrease in the Q of the antenna circuit.

This structure does not require space inside the set, making it possible to provide an external antenna terminal function even in small sets that previously could not be equipped with an external antenna terminal. , it became possible to design more high-performance equipment.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a rod antenna having a capacitance forming device according to the present invention, and FIG. 2 is an example of a state in which the device according to the present invention is used. DESCRIPTION OF SYMBOLS 1...Metal connection body, 2...Flange part, 3...Metal rod body, 4...Screw part, 5
...... Opposing metal body, 6... Threaded end of rod antenna, 7... Washer ゛8...
...Void area.

Claims (1)

[Scope of utility model registration request] A metal rod body in which a connecting metal body is provided with flanges at both ends of a cylindrical body, and a through hole passing through from one flange portion to the other flange portion is provided, and this through hole is provided at the tip of a rod antenna. At the same time, opposing metal bodies are arranged at positions facing both the flanges, the connecting metal body is used as one electrode, the metal rod body and both opposing metal bodies are used as the other electrode, and the above-mentioned one An insulator is interposed between the electrode and the other electrode, a capacitance is formed between the one electrode and the other electrode, and an external antenna lead wire can be connected to the connecting metal body. Rod antenna with capacitance forming device.