JPH0658603U - Tunable resonator - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a tunable resonator that can withstand high voltage and high power, expands the tuning frequency range, and has low cost, small size and light weight, and excellent electrical characteristics. A tip portion 2A of an inner conductor 2 concentrically provided at one short-circuited end of a hollow cylindrical outer conductor 1, and a central conductor inserted into the inner conductor 2 from the other open end of the outer conductor 1. The tip portion 3A of 3 is squared, or a Teflon pipe is brought into close contact with the inner surface of the inner conductor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tunable resonator such as a UHF band resonator using a semi-coaxial cavity resonator used in a wireless communication device or the like.

[0002]

[Prior art]

 FIG. 3 is a sectional view showing the configuration of an example of a conventional resonator. This conventional example is composed of an outer conductor 1, an inner conductor 2 and a central conductor 3 that slides in the axial direction. A drive source is a mechanism for converting the rotational motion of a motor into a linear motion, and the central conductor 3 is moved to the inner conductor 2. The tuning frequency is automatically changed by changing the moving length.

[0003]

[Problems to be solved by the device]

 The above-mentioned conventional example has the following problems. ． The outer diameter C of the inner conductor 2 and the inner diameter D of the outer conductor 1 must be maintained at a certain ratio in order to obtain electrical characteristics. As the outer diameter C of the inner conductor 2 increases, the outer conductor 1 is inevitably inevitable. Since the outer diameter of the device becomes large, the device cannot be downsized. ． The inner diameter B of the inner conductor 2 and the outer diameter A of the central conductor 3 must be maintained at a certain ratio in order to obtain electrical characteristics, and as described above, the size cannot be reduced. ． As the voltage / power is increased, air discharge is more likely to occur as the inner conductor 2 and the tip portions 2A, 3A of the central conductor 3 approach each other.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the resonator of the present invention squares the tips 2A and 3A of the inner conductor 2 and the center conductor 3 which constitute the tunable resonator together with the outer conductor 1, or the inner conductor 2 is formed on the inner surface of the inner conductor 2. The Teflon (trademark) pipe 4 is closely attached.

[0005]

[Action]

 As described above, by sharpening the tips 2A and 3A of the inner conductor 2 and the center conductor 3 or by adhering the Teflon pipe 4 inside the inner conductor 2, the withstand voltage and the withstand voltage are increased and the tuning frequency is increased. The range can be widened.

[0006]

【Example】

 FIG. 1 is a sectional view showing the structure of a first embodiment of the resonator of the present invention. The first embodiment is composed of an outer conductor 1, an inner conductor 2 and a center conductor 3, and a hollow cylindrical outer conductor 1 is concentrically connected to one short-circuited end of the hollow cylindrical outer conductor 1, A variable harmonic resonance that automatically adjusts the tuning frequency by inserting the center conductor 3 into the inner conductor 2 from the other open end of the conductor 1 and moving the center conductor 3 in the axial direction to adjust the movement length. In the container, the tip portions 2A, 3A of the inner conductor 2 and the center conductor 3 are squared to be circularly finished.

With this configuration, it is possible to prevent air discharge (spark) when the tips 2A and 3A of the inner conductor 2 and the center conductor 3 approach each other under high voltage and high power, and to prevent the conventional resonator 2 from It will be able to withstand double high voltage and high power. Further, the tuning frequency range in the UHF band can be widened, and the axial sliding width (movement amount) of the central conductor 3 for widening the tuning frequency range can be minimized. As described above, according to the first embodiment, it is possible to provide a tunable resonator that is low in cost, small in size and light in weight, and has excellent electrical characteristics.

FIG. 2 is a sectional view showing the structure of the second embodiment. In the second embodiment, the Teflon pipe 4 is inserted and closely attached to the inner surface of the inner conductor 2. In carrying out the second embodiment, the following problems occurred. ． Since the coefficient of linear expansion of Teflon changes remarkably with changes in temperature, it is difficult to maintain the processing accuracy and it becomes difficult to maintain close contact with the inner conductor 2, and the inner surface of the inner conductor 2 and the Teflon pipe 4 may slightly change. An air layer is created in the gap, making it easy to cause air discharge. ． When fixing the Teflon pipe 4 and the internal conductor 2 (brass material), there is no suitable adhesive, and fixing with screws inevitably deforms the Teflon pipe 4, which leads to deterioration of the electrical characteristics and also of the screws. The tip may induce air discharge.

As a result of careful consideration to overcome the above problems, the outer diameter of the Teflon pipe 4 is processed to be larger than the inner diameter of the inner conductor 2, liquid nitrogen (point cooler) is blown to the Teflon pipe 4, and heat shrinkage occurs. By inserting the Teflon pipe 4 into the inner conductor 2, the Teflon pipe 4 can be kept in close contact with the inner conductor 2 by absorbing the amount of contraction / expansion of the Teflon pipe 4 due to temperature change within a certain temperature range.

In the second embodiment described above, it is possible to withstand higher voltage and power than the conventional example and to widen the tuning frequency range without widening the gap 5 between the inner conductor 2 and the center conductor 3. Become. Further, the axial dimension can be reduced, and the gap 5 between the inner conductor 2 and the center conductor 3 can be reduced to about half that of the conventional one. In the second embodiment as well, it is possible to provide a tunable resonator which is low in cost, small in size and light in weight, and has excellent electric characteristics.

[0011]

[Effect of device]

 As is apparent from the above description, the hollow-cylindrical outer conductor 1, the hollow-cylindrical inner conductor 2 concentrically connected to one short-circuited end of the outer conductor 1, and the other open end of the outer conductor 1. The inner conductor 2 is axially moved from the inner conductor 2 into the inner conductor 2, and the inner conductor 2 and the tip portions 2A and 3A of the center conductor 3 are chamfered or the inner surface of the inner conductor 2 is teflon piped. 4 are closely contacted with each other, the hollow discharge due to the approaching of the inside and the center conductors 2 and 3 can be prevented by the chamfering of the two end portions 2A and 3A or the Teflon pipe 4 which is closely attached to the inner surface of the inner conductor 2. ， It is not only able to withstand a large amount of power, but also has the effect of widening the tuning frequency range, etc., and at the same time realizes small size and light weight at low cost, and provides a tunable resonator with excellent electrical characteristics. Obtainable .

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of a first embodiment of a resonator according to the present invention.

FIG. 2 is a sectional view showing a configuration of a second embodiment.

FIG. 3 is a sectional view showing a configuration of an example of a conventional resonator.

[Explanation of symbols]

 1 outer conductor 2 inner conductor 2A tip 3 center conductor 3A tip 4 Teflon pipe 5 gap

Claims (2)

[Scope of utility model registration request] 1. A hollow-cylindrical outer conductor (1) is concentrically connected to a hollow-cylindrical inner conductor (2) at one short-circuit end, and the inner conductor is opened from the other open end of the outer conductor (1). In the variable tuning resonator in which the tuning frequency is automatically adjusted by inserting the central conductor (3) into (2) and moving the central conductor (3) in the axial direction to adjust the moving length. 2) and the tip of the central conductor (3) (2A,
3A) is a tunable resonator obtained by shaving. 2. A hollow cylindrical outer conductor (1) is concentrically connected to one short-circuited end of the hollow cylindrical outer conductor (2), and the inner conductor is opened from the other open end of the outer conductor (1). In the variable tuning resonator in which the tuning frequency is automatically adjusted by inserting the central conductor (3) into (2) and moving the central conductor (3) in the axial direction to adjust the moving length. A tunable resonator in which a Teflon pipe (4) is closely attached to the inner surface of 2).