JP2011142460A - Method of automatically adjusting filter characteristic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of automatically adjusting filter characteristics that allows an automatic adjustment of a frequency adjustment screw or a coupling amount adjustment screw of a filter without involving a manual adjustment. <P>SOLUTION: A filter with the reflection properties preliminarily adjusted to predetermined ones is prepared, and an amount of phase and an amount of amplitude of the reflection properties of the adjusted filter are measured. Then, a plurality of adjusted frequency adjustment screws and a plurality of adjusted coupling amount adjustment screws in the adjusted filter, except for the last one of each, are rotated and transferred one by one at a time sequentially from the output terminal side toward the input terminal side so as to be turned into a non-adjusted state, and under this condition, an amount of phase and an amount of amplitude of the reflection properties are measured. Thereafter, the plurality of frequency adjustment screws in a non-adjusted state and the plurality of coupling amount adjustment screws in a non-adjusted state in the filter for adjustment are rotated and transferred one by one sequentially from the input terminal side toward the output terminal side so as to adjust the positions of the screws so that a square error of phase with respect to the previously measured amount of phase may be minimum. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a filter characteristic automatic adjustment method, and more particularly, to a technique for automatically adjusting reflection characteristics of a band-pass filter having a plurality of frequency adjustment screws and a plurality of coupling amount adjustment screws.

  In general, in a coaxial resonator type, dielectric resonator type band-pass filter (hereinafter simply referred to as BPF) or the like, the filter characteristics may be deviated from a design value due to a manufacturing error or the like. Therefore, coaxial resonator type, dielectric resonator type BPF, etc. are provided with a frequency adjusting screw for adjusting the resonance frequency of each coaxial resonator and a coupling amount adjusting screw for adjusting the coupling amount between the resonators. By adjusting the screws, the filter characteristics (reflection characteristics, transmission characteristics) are adjusted to approach the design values.

Japanese Patent No. 2000-114809

However, since adjustment of the frequency adjustment screw or adjustment of the coupling amount adjustment screw is performed manually by a highly skilled worker, adjustment of the frequency adjustment screw or coupling amount adjustment screw is troublesome. There was a point.
The present invention has been made to solve the problems of the prior art, and an object of the present invention is to adjust the frequency adjustment screw of the filter or the adjustment of the coupling amount adjustment screw by manual adjustment. An object of the present invention is to provide a filter characteristic automatic adjustment method that can be automatically performed without any problem.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) A filter characteristic automatic adjustment method for a filter having a plurality of frequency adjustment screws and a plurality of coupling amount adjustment screws, comprising: an initial setting step; and a characteristic adjustment step. A plurality of frequency adjusting screws and the plurality of coupling amount adjusting screws are adjusted to prepare a filter whose reflection characteristic is adjusted in advance to a predetermined characteristic, and within a predetermined frequency band including a center frequency of the adjusted filter. Measuring a phase amount and an amplitude amount of a reflection characteristic of the adjusted filter at the first to n-th frequencies, the plurality of adjusted frequency adjusting screws and the adjusted plurality of frequencies in the adjusted filter; For the coupling amount adjusting screw of the above, in the state in which the screw is rotated and moved sequentially one by one except for the last one from the output terminal side to the input terminal side, Or measuring the phase amount and the amplitude amount of the reflection characteristic of the nth frequency, and the characteristic adjustment step includes a step 3 of preparing an adjustment filter for adjusting the filter characteristic, and the adjustment The plurality of unadjusted frequency adjustment screws and the unadjusted coupling amount adjustment screws in the filter are sequentially rotated and moved one by one from the input terminal side to the output terminal side, and the first to nth And a step 4 of adjusting the screw position so that a phase square error with the phase amount measured in the initial setting step is minimized.

(2) In the characteristic adjustment step, after the step 4, at least once, the plurality of frequency adjustment screws and the plurality of coupling amount adjustment screws in the adjustment filter are sequentially applied from the input terminal side to the output terminal side. Rotate and move one by one to measure the amplitude of the reflection characteristics of the first to nth frequencies, so that the square error of amplitude with the amplitude of the reflection characteristics of the ideal filter is minimized. Step 5 is adjusted.
(3) In the characteristic adjustment step, after the step 5, at least once, the plurality of frequency adjustment screws and the plurality of coupling amount adjustment screws in the adjustment filter are sequentially applied from the input terminal side to the output terminal side. Rotate and move one by one to measure the amount of amplitude of the reflection characteristics of the first to nth frequencies, so that the fourth power error from the amplitude of the reflection characteristic of the ideal filter is minimized. Step 6 for adjusting the position is included.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the present invention, the adjustment of the frequency adjusting screw of the filter or the adjustment of the coupling amount adjusting screw can be automatically performed without manual adjustment.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the bandpass filter used as the object of the filter characteristic automatic adjustment method of the Example of this invention, and is principal part schematic cross section which shows the cross-section along the direction orthogonal to the axial length direction of a coaxial resonator It is. It is a principal part schematic cross section which shows the cross-section along an A-A 'cutting line of FIG. It is a principal part schematic cross section which shows the cross-section along a B-B 'cutting line of FIG. It is a graph for demonstrating the data obtained by the initial setting in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph for demonstrating the phase characteristic of the reflective characteristic obtained by the filter characteristic adjustment 1 in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph for demonstrating the phase characteristic of the reflective characteristic obtained by the filter characteristic adjustment 1 in the filter characteristic automatic adjustment method of the Example of this invention. It is a figure which shows the flowchart which shows the process sequence of the computer control of the filter characteristic adjustment 1 in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph which shows an example of the amplitude characteristic of the reflection characteristic of BPF after completion | finish of filter characteristic adjustment 1 in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph which shows an example of the phase characteristic of the reflective characteristic of BPF after completion | finish of filter characteristic adjustment 1 in the filter characteristic automatic adjustment method of the Example of this invention. It is a figure which shows the flowchart which shows the process sequence of the computer control of the filter characteristic adjustment 2 in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph which shows an example of the amplitude characteristic of the reflection characteristic of BPF after completion | finish of filter characteristic adjustment 2 in the filter characteristic automatic adjustment method of the Example of this invention. It is a figure which shows the flowchart which shows the process sequence of the computer control of the filter characteristic adjustment 3 in the filter characteristic automatic adjustment method of the Example of this invention. It is a graph which shows an example of the amplitude characteristic of the reflection characteristic of BPF after completion | finish of filter characteristic adjustment 3 in the filter characteristic automatic adjustment method of the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
[Description of Bandpass Filter Subject to Automatic Filter Characteristic Adjustment Method of Embodiment of Present Invention]
FIG. 1 is a diagram for explaining a band-pass filter (hereinafter referred to as BPF) that is an object of an automatic filter characteristic adjustment method according to an embodiment of the present invention, along a direction orthogonal to the axial length direction of the coaxial resonator. 2 is a schematic cross-sectional view showing a cross-sectional structure.
2 is a schematic cross-sectional view showing a cross-sectional structure taken along the line AA ′ of FIG. 1, and FIG. 3 is a schematic cross-sectional view showing a cross-sectional structure taken along the line BB ′ of FIG. is there.
1 to 3, 1 is an outer conductor, 2 is an inner wall, 3 is an input terminal, 4 is an output terminal, 9 is a connection input (or output) coupling loop, 10a to 10f are 1/4 coaxial resonators, 11a, 11b, 11c, 11d, 11e, and 11f are frequency adjusting screws, 12ab, 12bc, 12cd, 12de, and 12ef are coupling amount adjusting screws, and 15 is a coupling window.
The BPF shown in FIGS. 1 to 3 is a band filter having a six-stage configuration having six coaxial resonators (10a to 10f) in the outer conductor 1. FIG.
1 to 3, the outer conductor 1 is divided by an inner wall 2, and six coaxial resonators (10 a to 10 f) are arranged in the divided portion.
Each coaxial resonator (10a to 10f) is provided with a frequency adjusting screw (11a to 11f). By rotating the frequency adjusting screw (11a to 11f), each coaxial resonator (10a to 10f) is rotated. ) Resonance frequency can be adjusted.
As shown in FIG. 3, a coupling window 15 is formed on the inner wall 2 (inner wall in the direction from the input terminal 3 to the output terminal 4) between the coaxial resonators (10a to 10f). The coupling window 15 is inserted with coupling amount adjusting screws (12ab to 12ef). The amount of magnetic coupling between the coaxial resonators (10a to 10f) can be adjusted by rotating the coupling amount adjusting screw (12ab to 12ef).

The filter characteristic automatic adjustment method according to the embodiment of the present invention will be described below.
In the filter characteristic automatic adjustment method of this embodiment, the reflection characteristic and the transmission characteristic are optimized. Actually, if the reflection characteristic is optimized, the transmission characteristic is also optimized. Therefore, in the filter characteristic automatic adjustment method of this embodiment, the reflection characteristic is optimized.
The filter characteristic automatic adjustment method of the present embodiment is executed in the sequence of initial setting, filter characteristic adjustment 1, filter characteristic adjustment 2, and filter characteristic adjustment 3.
Hereinafter, each procedure will be described.
(1) Initial setting In this initial setting, a BPF that has been adjusted to the desired filter characteristics is prepared, data (amplitude characteristics and phase characteristics) are measured, and then the frequency adjustment screw and coupling amount adjustment screw are rotated one by one. -Move and measure the data in the unadjusted state. That is, first, a BPF adjusted to a desired filter characteristic is prepared, and the amplitude characteristic of the reflection characteristic and the phase characteristic of the reflection characteristic are measured for each of the first to nth frequencies (here, about 1600 frequencies). To do.
Next, the frequency adjustment screw 11f closest to the output terminal 4 is rotated and moved, and the frequency adjustment screw 11f is set in an unadjusted state, and the amplitude characteristic and the phase characteristic of the reflection characteristic for each of the first to nth frequencies are measured. In the present embodiment, the non-adjusted state of the frequency adjusting screw refers to a state in which the frequency adjusting screw is embedded in the outer conductor 1 from the position of the adjusted state.
Next, the coupling amount adjusting screw 12ef closest to the output terminal 4 is rotated and moved, and the coupling amount adjusting screw 12ef is set in an unadjusted state, and the amplitude characteristic and the phase characteristic of the reflection characteristic for each of the first to nth frequencies are obtained. taking measurement. In the present embodiment, the non-adjusted state of the coupling amount adjusting screw refers to a state in which the coupling amount adjusting screw is rotated and moved from the position of the adjusted state toward the outside of the external conductor 1.
The above-described processing is sequentially executed for all frequency adjustment screws and all coupling amount adjustment screws from the output terminal 4 toward the input terminal 3 except for the last one.

FIG. 4 is a graph for explaining data obtained by the above-described initial setting. In the graph of FIG. 4, the upper part shows the amplitude characteristic of the reflection characteristic, and the lower part shows the phase characteristic of the reflection characteristic. In the amplitude characteristics shown in FIG. 4, the vertical axis represents the attenuation (dB), and the horizontal axis represents the normalized frequency {(f / fo); fo is the design center frequency of the BPF}. The amount of increase / decrease of the frequency with respect to the center frequency (fo) is shown. Similarly, in the phase characteristics shown in FIG. 4, the vertical axis is the phase amount (deg), the horizontal axis is the normalized frequency (f / fo), and the increase / decrease of the frequency with respect to the design center frequency (fo). Indicates the amount.
FIG. 4A shows the amplitude characteristic and phase characteristic of the reflection characteristic of the BPF adjusted to the desired filter characteristic.
FIG. 4B shows a BPF that has been adjusted to a desired filter characteristic when two of the frequency adjusting screws (11a to 11f) and the coupling amount adjusting screws (12ab to 12ef) are in an unadjusted state. The amplitude characteristic and the phase characteristic of the reflection characteristic.
Similarly, FIG. 4C shows that in the BPF that has been adjusted to a desired filter characteristic, the four screws among the frequency adjustment screws (11a to 11f) and the coupling amount adjustment screws (12ab to 12ef) are in an unadjusted state. FIG. 4 (d) shows all frequency adjustment screws and coupling amount adjustment screws except for the last one in the BPF that has been adjusted to the desired filter characteristics. It is the amplitude characteristic and the phase characteristic of the reflection characteristic when it is in the unadjusted state.
In this initial setting, the order in which the screws are not adjusted is 11f → 12ef → 11e → 12de → 11d → 12cd → 11c → 12bc → 11b → 12ab → 11a and 11f → 11e → 12ef → 11d → The order may be 12de → 11c → 12cd → 11b → 12bc → 11a → 12ab.

(2) Filter characteristic adjustment 1
In this filter characteristic adjustment 1, first, a BPF for adjusting the filter characteristic is prepared. This BPF has the same dimensions as the filter used in the initial setting. Further, the frequency adjusting screws (11a to 11f) and the coupling amount adjusting screws (12ab to 12ef) are all unadjusted.
In this filter characteristic adjustment 1, the phase characteristic of the reflection characteristic for each of the first to nth frequencies is measured for each screw, and the phase 2 with the phase characteristic when each screw acquired in the initial setting is in the adjusted state. Calculate the power error. Then, the position where the phase square error is minimized is determined as the adjustment position of the screw being adjusted.
In this filter characteristic adjustment 1, the order of screws to be adjusted is the order opposite to the order in which the screws are not adjusted in the initial setting. For example, in the initial setting, if the order in which the screws are not adjusted is 11f → 12ef → 11e → 12de → 11d → 12cd → 11c → 12bc → 11b → 12ab → 11a, this filter characteristic adjustment 1 11a->12ab->11b->12bc->11c->12cd->11d->12de->11e->12ef-> 11f.
Similarly, in the initial setting, if the order in which the screws are not adjusted is 11f → 11e → 12ef → 11d → 12de → 11c → 12cd → 11b → 12bc → 11a → 12ab, this filter characteristic adjustment 1 12ab → 11a → 12bc → 11b → 12cd → 11c → 12de → 11d → 12ef → 11e → 11f.

Next, in the initial setting described above, the last unadjusted screw except the last remaining screw is rotated and moved, and the phase characteristics of the reflection characteristics for each of the first to nth frequencies are measured, The phase square error between the last remaining screw acquired in the initial setting and the phase characteristic when only the last unadjusted screw except the last remaining screw is adjusted is calculated. Then, the position where the phase square error is minimized is determined as the adjustment position of the screw being adjusted.
The above-described processing is executed for all frequency adjustment screws and all coupling amount adjustment screws from the output terminal 4 to the input terminal 3 in the order opposite to the order in which the screws are not adjusted in the initial setting. .
In this filter characteristic adjustment 1, when the variation of the phase square error is reduced and adjustment becomes difficult, an amplitude square error is obtained instead of the phase square error, and the amplitude square error is minimized. Is determined as the screw position. In the present embodiment, the screw squarely adjusted by the filter characteristic adjustment 1 or the screw immediately preceding from the last is obtained with an amplitude square error, and the position where the amplitude square error is minimized is determined as the screw position. As determined.
5 and 6 are graphs for explaining the phase characteristic of the reflection characteristic obtained by the filter characteristic adjustment 1. FIG. In the phase characteristics shown in FIG. 5, the vertical axis represents the phase amount (deg), and the horizontal axis represents the normalized frequency (f / fo), which indicates the amount of increase / decrease of the frequency with respect to the design center frequency (fo). .
FIG. 5 shows the phase characteristics after adjusting the screw position of the first screw (the last screw left on the input terminal 3 side in the above-described initial setting). FIG. 6 shows the phase characteristics after adjusting the screw positions of the five screws. 5 and 6, the solid line (ideal) is the phase characteristic of the reflection characteristic acquired by the initial setting, and the dotted line (tuned) is the phase characteristic of the reflection characteristic after adjusting the screw position.

The processing of the filter characteristic adjustment 1 is executed using a robot and under computer control. FIG. 7 is a flowchart showing the processing procedure of this computer control. Hereinafter, the processing procedure of the filter characteristic adjustment 1 executed by computer control will be described with reference to FIG.
First, the adjustment characteristic data (phase characteristic or amplitude characteristic obtained in the initial setting) of the adjustment target screw is read (step 101). Next, the adjustment target screw is a frequency adjustment screw or a coupling amount adjustment screw. Is determined, the robot is controlled, and the screw to be adjusted is rotated and moved to the start position (step 102). That is, it rotates and moves to a position close to the screw position of the adjustment target screw of the adjusted BPF used in the initial setting.
Next, the phase characteristic of the current reflection characteristic for each of the first to nth frequencies is acquired to calculate a phase square error, and the result is substituted into Err_old (step 103).
Next, control the robot, rotate and move the screw by the value of len, obtain the phase characteristic of the current reflection characteristic for each of the first to nth frequencies, calculate the phase square error, and calculate the result Substitute for Err_new (step 104).
Next, it is determined whether or not Err_new ≧ Err_old (step 105). If No in step 105 (Err_new <Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 106). ,
The above steps 104 and 105 are repeated.
If Yes in step 105 (if Err_new ≧ Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 107), the value of len is multiplied by an attenuation coefficient, and the multiplied value is multiplied. len (step 108).

Next, it is determined whether or not the value of len is equal to or smaller than the minimum value (Step 109). If No in Step 109, the processing from Step 104 described above is repeated. When the process from step 104 is repeated, the rotation direction of the adjustment target screw by the robot is opposite to the rotation direction up to step 108.
If YES in step 109, the adjustment of the current adjustment target screw is completed. In step 110, it is determined whether there is a next adjustment target screw. If YES in step 110 (next adjustment target) If there is a screw), the robot is moved to the next adjustment target screw (step 111), and the processing from step 101 described above is repeated.
If No in step 110 (when there is no next adjustment target screw), the process (the process of filter characteristic adjustment 1) is terminated.
FIG. 8 is a graph showing an example of the amplitude characteristic of the reflection characteristic of the BPF after completion of the filter characteristic adjustment 1, and FIG. 9 is a graph showing an example of the phase characteristic of the reflection characteristic of the BPF after completion of the filter characteristic adjustment 1. is there.
In FIG. 8, the vertical axis represents the attenuation (dB), and the horizontal axis represents the normalized frequency (f / fo), which indicates the amount of increase / decrease of the frequency with respect to the design center frequency (fo). In FIG. 9, the vertical axis represents the phase amount (deg), and the horizontal axis represents the normalized frequency (f / fo), which indicates the amount of increase / decrease of the frequency with respect to the design center frequency (fo).
8 and 9, the solid line (edeal) indicates the amplitude characteristic and phase characteristic of the adjusted BPF, and the dotted line (tuned) indicates the amplitude characteristic and phase characteristic of the BPF after completion of the filter characteristic adjustment 1.
When the filter characteristic of the BPF prepared for adjusting the filter characteristic becomes a desired characteristic by this filter characteristic adjustment 1, the process for adjusting the filter characteristic is ended, but the filter characteristic is adjusted. If the filter characteristics of the BPF prepared in step 1 do not become the desired characteristics, the following filter characteristic adjustment 2 is executed.

(3) Filter characteristic adjustment 2
In this filter characteristic adjustment 2, the amplitude characteristic of the reflection characteristic for each of the first to nth frequencies is measured for each screw, and the amplitude square error with respect to the amplitude characteristic of the reflection characteristic of the ideal Chebyshev filter is calculated. Then, the position where the amplitude square error is minimized is determined as the adjustment position of the adjusting screw.
In the filter characteristic adjustment 2, the order of the screws to be adjusted is the order opposite to the order in which the screws are not adjusted in the initial setting. For example, in the initial setting, if the order in which the screws are not adjusted is 11f → 12ef → 11e → 12de → 11d → 12cd → 11c → 12bc → 11b → 12ab → 11a, this filter characteristic adjustment 1 11a->12ab->11b->12bc->11c->12cd->11d->12de->11e->12ef-> 11f.
Similarly, in the initial setting, if the order in which the screws are not adjusted is 11f → 11e → 12ef → 11d → 12de → 11c → 12cd → 11b → 12bc → 11a → 12ab, this filter characteristic adjustment 1 12ab → 11a → 12bc → 11b → 12cd → 11c → 12de → 11d → 12ef → 11e → 11f.

Next, in the initial setting described above, the last unadjusted screw except the last remaining screw is rotated and moved, and the amplitude characteristic of the reflection characteristic for each of the first to nth frequencies is measured, An amplitude square error with the amplitude characteristic of the ideal reflection characteristic of the Chebyshev filter is calculated. Then, the position where the amplitude square error is minimized is determined as the adjustment position of the adjusting screw.
The above-described processing is executed for all frequency adjustment screws and all coupling amount adjustment screws from the output terminal 4 to the input terminal 3 in the order opposite to the order in which the screws are not adjusted in the initial setting. .

The processing of the filter characteristic adjustment 2 is also executed under computer control using a robot. FIG. 10 is a flowchart showing the computer-controlled processing procedure. Hereinafter, the processing procedure of the filter characteristic adjustment 2 executed by computer control will be described with reference to FIG.
First, reflection characteristic data of an ideal Chebyshev filter is read (step 201).
Next, the amplitude characteristic of the current reflection characteristic for each of the first to n-th frequencies is acquired to calculate an amplitude square error, and the result is substituted into Err_old (step 202).
Next, the robot is controlled by the value of len, the screw is rotated and moved, the amplitude characteristic of the current reflection characteristic for each of the first to nth frequencies is obtained, the square error of amplitude is calculated, and the result is Substitute for Err_new (step 203).
Next, it is determined whether Err_new ≧ Err_old (step 204). If No in step 204 (if Err_new <Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 205). ,
Steps 203 and 204 described above are repeated.
In the case of Yes in step 204 (when Err_new ≧ Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 206), the value of len is multiplied by an attenuation coefficient, and the multiplied value is obtained. len (step 207).
Next, it is determined whether or not the value of len is equal to or smaller than the minimum value (step 208). If No in step 208, the processing from step 204 described above is repeated. When the process from step 204 described above is repeated, the rotation direction of the adjustment target screw is opposite to the rotation direction up to step 207.

If YES in step 208, the adjustment of the current adjustment target screw is completed. In step 209, it is determined whether there is a next adjustment target screw. If YES in step 209, the next adjustment target screw is determined (next adjustment target). If there is a screw), the robot is moved to the next adjustment target screw (step 210), and the processing from step 201 described above is repeated.
If No in step 209 (when there is no next adjustment target screw), the processing (processing for filter characteristic adjustment 2) is terminated.
This filter characteristic adjustment 2 is executed once or more. In addition, when the filter characteristic of the BPF prepared for adjusting the filter characteristic becomes a desired characteristic by this filter characteristic adjustment 2, the process for adjusting the filter characteristic ends, but the filter characteristic is adjusted. When the filter characteristic of the BPF prepared for this is not a desired characteristic, the following filter characteristic adjustment 3 is executed.
FIG. 11 is a graph showing an example of the amplitude characteristic of the reflection characteristic of the BPF after completion of the filter characteristic adjustment 2.
In FIG. 11, the vertical axis represents the attenuation (dB), and the horizontal axis represents the normalized frequency (f / fo), which indicates the amount of increase / decrease of the frequency with respect to the design center frequency (fo).
In FIG. 11, the solid line (1 cycle) indicates the amplitude characteristic of the BPF after the end of the filter characteristic adjustment 1, the broken line (2 cycle) indicates the amplitude characteristic of the BPF after the end of the first filter characteristic adjustment 2, and the dotted line (3 cycle) indicates the amplitude characteristic. An amplitude characteristic of the BPF after completion of the second filter characteristic adjustment 2 is shown.
In this filter characteristic adjustment 2, instead of the amplitude characteristic of the reflection characteristic of the ideal Chebyshev filter, the amplitude characteristic of the reflection characteristic of the BPF that has been adjusted to the desired filter characteristic obtained in the filter characteristic adjustment 1 is used. You may do it.

(4) Filter characteristic adjustment 3
In the filter characteristic adjustment 3, for each screw, the amplitude characteristic of the reflection characteristic for each of the first to nth frequencies is measured, and the fourth power error with the amplitude characteristic of the reflection characteristic of the ideal Chebyshev filter is calculated. Then, the position where the fourth power error is minimized is determined as the adjustment position of the adjusting screw.
In the filter characteristic adjustment 3, the order of screws to be adjusted is the order opposite to the order in which the screws are not adjusted in the initial setting. For example, in the initial setting, if the order in which the screws are not adjusted is 11f → 12ef → 11e → 12de → 11d → 12cd → 11c → 12bc → 11b → 12ab → 11a, this filter characteristic adjustment 1 11a->12ab->11b->12bc->11c->12cd->11d->12de->11e->12ef-> 11f.
Similarly, in the initial setting, if the order in which the screws are not adjusted is 11f → 11e → 12ef → 11d → 12de → 11c → 12cd → 11b → 12bc → 11a → 12ab, this filter characteristic adjustment 1 12ab → 11a → 12bc → 11b → 12cd → 11c → 12de → 11d → 12ef → 11e → 11f.

Next, in the initial setting described above, the last unadjusted screw except the last remaining screw is rotated and moved, and the amplitude characteristic of the reflection characteristic for each of the first to nth frequencies is measured, An amplitude fourth power error with the amplitude characteristic of the ideal reflection characteristic of the Chebyshev filter is calculated. Then, the position where the fourth power error is minimized is determined as the adjustment position of the adjusting screw.
The above-described processing is executed for all frequency adjustment screws and all coupling amount adjustment screws from the output terminal 4 to the input terminal 3 in the order opposite to the order in which the screws are not adjusted in the initial setting. .

The processing of the filter characteristic adjustment 3 is also executed under computer control using a robot. FIG. 12 is a flowchart showing the computer-controlled processing procedure. Hereinafter, the processing procedure of the filter characteristic adjustment 3 executed by computer control will be described with reference to FIG.
First, reflection characteristic data of an ideal Chebyshev filter is read (step 301).
Next, the amplitude characteristic of the current reflection characteristic for each of the first to n-th frequencies is acquired, an amplitude fourth power error is calculated, and the result is substituted into Err_old (step 302).
Next, the robot is controlled by the value of len, the screw is rotated / moved, the amplitude characteristic of the current reflection characteristic for each of the first to n-th frequencies is obtained, and the fourth power error is calculated. Substitute for Err_new (step 303).
Next, it is determined whether or not Err_new ≧ Err_old (step 304). If No in step 304 (if Err_new <Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 305). ,
Steps 303 and 304 described above are repeated.
If Yes in step 304 (if Err_new ≧ Err_old), Err_old is replaced with the value of Err_new, that is, Err_old = Err_new (step 306), and the value obtained by multiplying the value of len by the attenuation coefficient is multiplied by len (step 307).
Next, it is determined whether or not the value of len is equal to or less than the minimum value (step 308). When the process from step 304 described above is repeated, the rotation direction of the adjustment target screw is opposite to the rotation direction up to step 307.

If Yes in step 308, the adjustment of the current adjustment target screw is completed, and it is determined in step 309 whether there is a next adjustment target screw. If yes in step 309 (next adjustment target If there is a screw), the robot is moved to the next adjustment target screw (step 310), and the processing from step 301 described above is repeated.
If No in step 309 (when there is no next adjustment target screw), the process (the process of filter characteristic adjustment 3) ends.
FIG. 13 is a graph showing an example of the amplitude characteristic of the reflection characteristic of the BPF after completion of the filter characteristic adjustment 3. In FIG. 13, the vertical axis represents the attenuation (dB), and the horizontal axis represents the normalized frequency (f / fo), which indicates the amount of increase / decrease of the frequency with respect to the design center frequency (fo).
In FIG. 13, the solid line (before) indicates the amplitude characteristic of the BPF after completion of the filter characteristic adjustment 2, and the dotted line (after) indicates the amplitude characteristic of the BPF after completion of the filter characteristic adjustment 3.
In the filter characteristic adjustment 2 and the filter characteristic adjustment 3, since the characteristic of the reflection region of the reflection characteristic is hardly changed, the frequency for obtaining the amplitude characteristic may be limited to the pass band of the reflection characteristic. In this case, the adjustment time can be shortened.
Also in this filter characteristic adjustment 3, instead of the amplitude characteristic of the reflection characteristic of the ideal Chebyshev filter, the amplitude characteristic of the reflection characteristic of the BPF adjusted to the desired filter characteristic obtained in the above-mentioned filter characteristic adjustment 1 is used. You may make it do.

As shown in FIG. 13, according to the filter characteristic automatic adjustment method of the present embodiment, it is possible to obtain an attenuation amount of −20 dB to −23 dB as the return loss of the passband.
As described above, according to the present embodiment, the adjustment of the frequency adjusting screw of the filter or the adjustment of the coupling amount adjusting screw can be automatically performed using the robot without manual adjustment. . Thereby, the adjustment time of the frequency adjustment screw or the adjustment time of the coupling amount adjustment screw can be shortened, so that the cost of the BPF can be reduced.
In the above description, the embodiment in which the present invention is applied to the coaxial resonator type BPF has been described. However, the present invention is not limited to this, and the present invention is not limited to the dielectric resonator type BPF. As described above, the present invention can be applied to a BPF having a frequency adjusting screw or a coupling amount adjusting screw. Furthermore, the present invention can also be applied to a band elimination filter having a frequency adjustment screw or a coupling amount adjustment screw.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

DESCRIPTION OF SYMBOLS 1 Outer conductor 2 Inner wall 3 Input terminal 4 Output terminal 9 Connection input (or output) coupling loop 10a-10f 1/4 coaxial resonator 11a-11f Frequency adjustment screw 12ab, 12bc, 12cd, 12de, 12ef Coupling amount adjustment screw 15 Coupling window

Claims (4)

A filter characteristic automatic adjustment method for a filter having a plurality of frequency adjustment screws and a plurality of coupling amount adjustment screws,
An initial setting step;
Characteristic adjustment step,
The initial setting step adjusts the plurality of frequency adjustment screws and the plurality of coupling amount adjustment screws, prepares a filter whose reflection characteristic is adjusted in advance to a predetermined characteristic, and sets the center frequency of the adjusted filter. Measuring a phase amount and an amplitude amount of the reflection characteristic of the adjusted filter of the first to nth frequencies within a predetermined frequency band including;
The plurality of adjusted frequency adjusting screws and the plurality of adjusted coupling amount adjusting screws in the adjusted filter are sequentially rotated one by one from the output terminal side to the input terminal side except for the last one. Measuring a phase amount and an amplitude amount of the reflection characteristics of the first to nth frequencies in a state of being moved and brought into an unadjusted state;
The characteristic adjustment step includes a step 3 of preparing an adjustment filter for adjusting a filter characteristic;
The plurality of frequency adjustment screws in an unadjusted state and the plurality of coupling amount adjustment screws in an unadjusted state in the adjustment filter are sequentially rotated and moved one by one from the input terminal side to the output terminal side, Measuring the phase amount of the reflection characteristics of the 1st to n-th frequencies, and adjusting the screw position so that the phase square error with the phase amount measured in the initial setting step is minimized. A characteristic filter characteristic automatic adjustment method.   In step 4, at least one screw on the most output terminal side is an amplitude square of the measured amplitude amount of the reflection characteristics of the first to nth frequencies and the amplitude amount measured in the initial setting step. 2. The filter characteristic automatic adjustment method according to claim 1, wherein the screw position is adjusted so that the error is minimized.   In the characteristic adjustment step, after the step 4, at least once, a plurality of frequency adjustment screws and a plurality of coupling amount adjustment screws in the adjustment filter are sequentially arranged one by one from the input terminal side to the output terminal side. Rotate and move to measure the amplitude of the reflection characteristics of the first to nth frequencies, and adjust the screw position so that the square error of amplitude with the amplitude of the reflection characteristics of the ideal filter is minimized. 3. The filter characteristic automatic adjustment method according to claim 1, further comprising step 5.   In the characteristic adjustment step, after the step 5, at least once, a plurality of frequency adjustment screws and a plurality of coupling amount adjustment screws in the adjustment filter are sequentially arranged one by one from the input terminal side to the output terminal side. Rotate and move to measure the amplitude of the reflection characteristics of the first to nth frequencies, and adjust the screw position so that the fourth power error with the amplitude of the reflection characteristics of the ideal filter is minimized. 4. The filter characteristic automatic adjustment method according to claim 3, further comprising:

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