JPS62225023A - Coaxial equalizer - Google Patents

Abstract

PURPOSE:To miniaturize the titled equalizer and to easily correct an output frequency characteristic uniformly by providing a sub coaxial line whose open end is opposed to a center conductor of a main coaxial line and a sub coaxial line connected to the center conductor. CONSTITUTION:The open end tip of the center conductors 3A,3B of the sub coaxial line is opposed at a right angle to the center conductor 2 of the main coaxial line separately. Furthermore, the open end tip of the center conductor 3C of the sub coaxial line is in contact with the conductor 2 at a right angle. A series resonance circuit having a high Q characteristic depending on the inductance by the length of the center conductor from the open end to the short-circuit end and the capacitance between the conductors 2 and 3 is formed in the sub coaxial line separated from the conductor 2 and a resonance circuit having a mitigated attenuation is formed in the sub coaxial line connected to the conductor 2. Thus, the latter resonance circuit corrects the frequency characteristic changed slowly in the power gain and the former resonance circuit corrects the characteristic changed steeply, thereby allowing uniform equalization over the entire frequency region.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a coaxial equalizer used in microwave band amplifiers and electron tubes.

2. Description of the Related Art Conventionally, equalizers have been used to correct frequency-dependent changes in power gain in microwave band amplifiers and electron tubes. Such an equalizer is described by G. L. Raga [Microwave Transmission Circuits].
[:1rcuits) jMIT Radiation Laboratory Series (MIT Radia
tionLaboratory 5eries)
vol, 9. ? Tagraw Hill Company (McGraw-1
1i11) Coaxial equalizers such as the slug tuner and slug tuner described on pages 466-478, published in 1948, were used.

Problems to be Solved by the Invention The slug tuner and coaxial equalization using the slug tuner are
Although the shape can be made relatively small, the Q characteristic as a resonator is low. Therefore, if the power gain of an amplifier or electron tube has complex characteristics such as a steep change in a gentle slope with respect to frequency, it is difficult to correct it.

Therefore, in order to obtain high Q characteristics, a method is known in which the waveguide is converted into a waveguide. However, this system has problems such as the use of a waveguide, which increases the size of the system, and the possibility of mismatching in the coaxial-waveguide conversion section.

The present invention solves the above-mentioned conventional problems and provides a small coaxial equalizer that can uniformly correct the frequency characteristics when the power gain of an amplifier or electron tube has complex characteristics with respect to frequency. We aim to provide the following.

Means for solving the problem, namely, according to the present invention, a main coaxial line, a main coaxial line, and a center conductor of the main coaxial line with the tip of the center conductor on the open end side facing away from each other, one end short-circuited and the other end At least one control axis line is open, and at least one control axis line is short-circuited at one end and open at the other end, the tip of the center conductor on the open end side being in contact with the center conductor of the main coaxial line. A coaxial equalizer is provided.

In the coaxial type equalizer of the present invention as described above, the control axis line in which the center conductor faces the center conductor of the main coaxial line at a distance,
It is electrically coupled to the center conductor of the main coaxial line. This control axis line has a high Q characteristic determined by the inductance L due to the length of the center conductor from the open end to the shorted end of the control axis line and the capacitance C between the main coaxial line and the center conductor of the control axis line. A series resonant circuit is formed. Therefore, a resonant circuit having a high Q characteristic at a desired resonant frequency is constructed by these control axis lines, so that a sharp damping characteristic can be realized at a desired damping frequency.

On the other hand, in a restrained axis line in which the center conductor is in direct contact with the center conductor of the main coaxial line, a series resonant circuit is not formed, but a resonant circuit with a gentle damping characteristic is formed.

Therefore, even if the power gain of an amplifier or electron tube has complex characteristics such as a steep change with a gentle slope with respect to frequency, the coaxial equalizer of the present invention can be used. A resonant circuit with a gentle damping characteristic in the center corrects the frequency characteristic part where the power gain changes slowly, and a resonant circuit with a high Q characteristic corrects the steep change in the frequency characteristic part where the power gain changes. The portions can be corrected to equalize across the frequency range.

In addition, since no waveguide is used and the device is composed of only coaxial lines, it does not become bulky, eliminates the need for coaxial-to-waveguide conversion, and eliminates mismatching caused by the conversion.

Example Next, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

The main coaxial line is composed of a center conductor 2 extending between input and output terminals IA and 18, and an outer conductor block 4 having an inner surface 4A coaxial with the center conductor.

The center conductor 2 is connected to the center conductor 3 of the control axis line.
The open end tips of A and 3B face each other at right angles and are located apart. On the other hand, the open end side tip of the center conductor 3C of the control axis line is in contact with the center conductor 2 at right angles. A cavity having an inner surface 4B coaxial with the center conductors 3A, 3B, and 3C (hereinafter referred to as the center conductor 3 when there is no need to distinguish between them) communicates with the cavity around the center conductor of the main coaxial line 2. The outer conductor block 4 is further formed with the same structure. Therefore, the outer conductor of the main coaxial line and the control axis line is common.

Further, a short circuit 5 is provided to close the space between the center conductor 3 of the control axis line and the inner surface 4B of the outer conductor block 4 surrounding it. The short circuit 5 is adapted to be able to slide on the center conductor 3. Further, screws 6 and 7 are screwed into the bottom of the outer conductor block 4 , and their tips are connected to the lower end of the center conductor 3 and the short circuit 5 .

However, the screw 6 is not provided in the center conductor 3C.

In this configuration, the screw 6 can adjust the position of the center conductor of the control axis line, and the screw 7 can adjust the position of the short circuit, that is, the length between the open end and the shorted end of the center conductor of the control axis line. Can be adjusted.

In the above-mentioned embodiment, the outer conductor of the main coaxial line and the sub-coaxial line is made common as the outer conductor block 4, and the structure is such that three sub-surface axial lines are combined with the main coaxial line. There is. However, the outer conductors of the main coaxial line and the sub-plane axial line may be separate bodies, and the number of sub-plane axial lines can be arbitrarily selected depending on the required characteristics of the equalizer.

In the above coaxial equalizer, the center conductors 3A and 3B
For a sub-plane axial line where the main coaxial line is far away from the center conductor 2, use the adjusting screw 7 to adjust the position of the short circuit of the sub-plane axial line.
By changing the inductance L of the sub-plane axial line, the inductance L of the sub-surface axial line can be varied, and by changing the distance between the center conductor 2 of the main coaxial line and the center conductor 3 of the sub-plane axial line with the adjustment screw 6, the center conductor 2 The capacitance C between and the center conductor 3
can be varied. Therefore, the subsurface axial line operates as a frequency variable series resonant circuit. This resonant circuit is coupled to the main coaxial line through the capacitance C mentioned above. Therefore, if the capacitance C is reduced by increasing the distance between the center conductor 2 and the center conductor 3, the energy flowing out from the resonant circuit of the subsurface axial line to the main coaxial line will be reduced, so that an extremely high Q characteristic can be obtained. The resonant frequency can be arbitrarily selected by correcting the decrease in capacitance C by increasing the inductance L by changing the position of the short circuit 6 using the adjusting screw 7.

On the other hand, in a subsurface axial line in which the center conductor 3C is connected to the center conductor 2 of the output coaxial line, the inductance L of the subsurface axial line can be adjusted by changing the position of the short circuit 5 of the subsurface axial line with the adjusting screw 7. Can be changed. Therefore, a variable frequency resonant circuit is constructed, and since it is continuous with the main coaxial line, the resonant circuit has gentle characteristics. In addition, the center conductor 3
Since C is connected to the center conductor 2 of the main coaxial line, the main coaxial line 2 is supported by the outer conductor 4 via the sub-surface axial line 3 and the short circuit 5, and has a high mechanical strength, that is, resistance to vibration shock. protected.

FIG. 2 shows the frequency characteristics of the amount of attenuation in the coaxial equalizer of the embodiment. By causing the two subsurface axis lines corresponding to the center conductors 3A and 3B to resonate at different frequencies, it is possible to create two places where the attenuation changes sharply with respect to the frequency. In addition, the circuit in which the main coaxial line and the sub-surface axial line are connected by the center conductor 3C makes it possible to create a gradual change in the amount of attenuation with respect to frequency.

DETAILED DESCRIPTION OF THE INVENTION As described in detail, the present invention provides a coaxial equalizer in which one end of the main coaxial line is short-circuited, and the other end is placed opposite the center conductor of the main coaxial line, with an open sub-surface axial line. At the same time,
By arranging a subsurface axial line with one end short-circuited and the other end connected to the center conductor of the main coaxial line, the power gain of the amplifier or electron tube can be adjusted to have complex characteristics with respect to frequency without increasing the size. If so, the output frequency characteristics can be easily corrected to be uniform.

Each resonance frequency can be easily adjusted by adjusting the length from the open end to the short-circuited end of the secondary surface axis line. In addition, the sub-plane axis line, in which the center conductor faces away from the center conductor of the main coaxial line, is electrically coupled to the main coaxial line, so compared to the conventional stub tuner structure, the sub-plane axis line is Since the outflow of energy from the resonant circuit of the line to the main coaxial line can be reduced, high Q characteristics can be achieved. Moreover, the Q characteristic can be varied by changing the distance between the center conductor of the main coaxial line and the center conductor of the sub-plane axial line.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of a coaxial equalizer according to the present invention, and FIG. 2 is a graph showing the frequency characteristics of attenuation in the embodiment of FIG. [Main reference numbers] IA, IB...Input/output terminal, 2...Center conductor of main coaxial line, 3...Center conductor of sub-surface axial line, 4...Outer conductor block, 5...Short circuit, 6・・Center conductor position adjustment screw for secondary surface axis line, 7.・Short-circuit type position adjustment screw

Claims (1)

[Claims] a main coaxial line, at least one sub-coaxial line with one end short-circuited and the other end open, the center conductor of the main coaxial line having a tip of the center conductor on the open end side separated from the center conductor of the main coaxial line; 1. A coaxial equalizer comprising at least one sub-coaxial line with one end short-circuited and the other end open, with the tip of a center conductor on the open end side being in contact with the coaxial line.