JPH0752206B2 - Filter adjuster - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter adjusting device having one or two or more adjusting points which are formed by using lumped constant elements or distributed constant elements.

[0002]

2. Description of the Related Art As is well known, a filter constructed using lumped constant elements or distributed constant elements rarely obtains desired characteristics simply by being assembled, and requires some artificial adjustment. There are many cases. this is,
This is because the characteristics of the filter change greatly with a slight error in the values of the constituent elements, but the desired characteristics cannot be obtained simply by suppressing the error of each element to the limit in terms of manufacturing technology.

Therefore, it is necessary to adjust each element of the filter while observing the overall input / output characteristics until the required characteristics are obtained. This is an adjustment method that has been generally adopted conventionally.

Specifically, for example, it is performed as shown in FIG. This is based on the literature “Mirzai et al,“ Intelligent Alig
nment of Waveguide Filters using a Machine Learnin
gApproach ”IEEE Transactions on Microwave Theory a
nd Techniques, vol.37, No.1, January 1987. Of 168
It is a filter adjustment support system using the machine introduced on the page.

In FIG. 6, the filter 1 is, for example, a microwave band pass filter, which is provided with a plurality of element adjusting screws 5. The scalar network analyzer 6 is caused to display the comprehensive input / output characteristics of the filter 1. FIG. 7 is a display example in which the frequency locus of the reflection coefficient vector at the input end of the filter 1 is displayed as a scalar quantity at the coordinates of the horizontal axis frequency and the vertical axis amplitude [dB].
The plurality of adjusting screws 5 are individually adjusted while observing this display so that 1 is the characteristic 42.

That is, since there is no direct correlation between the display of the scalar network analyzer 6 (total characteristic of the filter) and each element value, the proper adjusting screw 5 is selected depending on the intuition and experience. , Make adjustment work.

[0007]

As described above, in the conventional filter adjustment method, the total characteristics are observed by using a measuring instrument, but since there is no association with the adjustment point, the final result is human skill. Since there is no choice but to rely on it, the processing time varies depending on the person, and there is a problem that efficiency improvement such as shortening of adjustment time is naturally limited.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a filter adjusting device which enables simplification or automation of adjustment work without depending on human skill. is there.

[0009]

The filter adjusting device of the present invention has the following structure. That is, the filter adjusting device according to the first aspect of the present invention includes a lumped constant element or a distributed constant element, and a filter having one or more adjustment points, the reflection coefficient viewed from the input end or the transmission coefficient viewed from the output end. A measuring instrument that measures one or both coefficients as vector information over two or more frequency points; a difference between a value measured by the measuring instrument and a value calculated in an equivalent circuit of the filter is minimized. An arithmetic unit for calculating a state value of an element in the equivalent circuit, and determining an adjustment direction and an adjustment amount of a corresponding adjustment point of the filter so that the state value matches a target value. Is.

The filter adjusting apparatus according to the second aspect of the present invention is the filter adjusting apparatus according to the first aspect of the present invention, further comprising: an apparatus for physically adjusting a corresponding adjustment point of the filter based on a calculation result of the calculation apparatus. It is what

[0011]

Next, the operation of the filter adjusting device of the present invention constructed as described above will be described. According to the present invention, the reflection coefficient and the transmission coefficient of the filter are measured as vector information over two or more frequencies, and the difference between the measured value and the value calculated by the equivalent circuit of the filter is the minimum. The state value of the element value at is calculated, and the adjustment direction and the adjustment amount of the corresponding adjustment location of the filter are determined so that the state value matches the target value.

Therefore, the adjustment worker only has to adjust the relevant portion according to the output value of the apparatus, and the adjustment work is greatly simplified. Further, if the device for physically adjusting the corresponding adjustment point is provided as in the second aspect of the invention, the adjustment work can be automated.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a filter adjusting device according to an embodiment of the present invention. In this embodiment, a filter (for example, a microwave band pass filter) configured by using the distributed constant element similar to that in FIG. 6 will be described as an example.

The filter 1 comprises a plurality of screw elements 5 for adjusting elements.
In the illustrated example, the output end (left side in the figure) is terminated and the input end (right side in the figure) is connected to the vector network analyzer 2.

That is, the vector network analyzer 2 measures the reflection coefficient at the input end of the filter 1 as vector information over a plurality of frequency points. This measurement is
For example, the characteristics are as shown in FIG. In FIG. 2, the vector locus 21 shown by the broken line is before adjustment, and is adjusted so as to become the vector locus 22 shown by the solid line. Note that FIG. 7 shows the frequency locus of the reflection coefficient vector shown in FIG. 2 as a scalar quantity.

The arithmetic unit 3 receives the output measurement value of the vector network analyzer 2 and executes the processing algorithm according to the procedure shown in FIG. 3 to set the adjustment direction and the adjustment amount of each adjustment screw 5 to the adjustment screw rotation mechanism 4. Specify output. The operation will be described below with reference to FIG.

In FIG. 3, the equivalent circuit (1) of the filter 1 is, for example, as shown in FIG. 4, and the data of this equivalent circuit is set in the arithmetic unit 3. In the arithmetic unit 3, the initial value is first set. As a theoretical value is given to each element value of this equivalent circuit, the input reflection coefficient S ₁₁ is calculated over a plurality of frequency points, and the calculated value S ₁₁ (2) and the measured value S ₁₁ ′ (of the vector network analyzer 2) The difference with 3) is compared (4).

The input reflection coefficient S ₁₁ is repeatedly calculated while correcting (6) the element value of the equivalent circuit until the difference becomes minimum (5), and each of the equivalent circuits at the time when the difference becomes minimum. The element value is held as an analysis value (state value) indicating the actual value of each element of the filter 1 (7).

On the other hand, the target value (8) of each element of the equivalent circuit shown in FIG. 4 is a value theoretically given as follows: if the filter 1 is, for example, a Chebyshev filter, then it is given by equation 1.

[0020]

## EQU1 ## L _i = w / 2πf ₀ g _i C _i = g _i / 2πf ₀ w where w = Δf / f ₀ , i = 1,2,3, ..., n

In Equation 1, f ₀ is the center frequency, Δf is the bandwidth, n is the number of stages, and g _i is the element value of the basic low pass filter.

Thus, if the difference between the analysis value (7) and the target value (8) is obtained (9), the individual adjustment direction and adjustment amount of the adjusting screw 5 can be designated and output.

The adjusting screw rotating mechanism 4 can individually rotate each adjusting screw 5 of the filter 1 in a specified direction by a specified amount based on the output data of the arithmetic unit 3 to correct the characteristics of the filter 1.

Then, the reflection coefficient at the input end of the filter 1 whose characteristic has been modified is again analyzed by the vector network analyzer 2.
Is measured and given to the arithmetic unit 3.

The arithmetic unit 3 calculates the analysis value (7) by using the previous analysis value as an initial value, executes the same calculation as described above, and calculates the difference from the target value (8). Then, if there is no difference as a result of the difference calculation (9), it is determined that the filter 1 can be adjusted to the desired characteristic (characteristic 22 in FIG. 2), and the adjustment operation ends. On the other hand, if there is a difference, the adjustment routine described above is repeatedly executed until the difference disappears. As a result, the characteristic 22 can be finally obtained. The calculation value is taken into consideration when the previous analysis value is used as the initial value.

Although FIG. 1 shows a case where adjustment is performed automatically without human intervention, as shown in FIG.
The adjustment screw rotating mechanism 4 is omitted, and the result of the difference calculation (9) is displayed on the arithmetic unit 3 so that the operator can check the result with the eyes 7 and individually adjust the adjustment screws 5 with the hands 8. Is also good. Even in this case, the arithmetic unit 3 displays and outputs the adjustment direction and the adjustment amount in a one-to-one correspondence with the adjustment screw 5, so that the adjustment efficiency is significantly improved as compared with the conventional method, and the adjustment work can be completed in a short time.

[0027]

As described above, in the filter adjusting apparatus of the present invention, the reflection coefficient and the transmission coefficient of the filter are measured as vector information over two or more frequencies, and calculated from the measured value and the equivalent circuit of the filter. The state value of the element value in the equivalent circuit where the difference value with the value obtained in step 2 is the minimum is obtained, and the adjustment direction and the adjustment amount of the corresponding adjustment point of the filter are determined so that the state value matches the target value. Therefore, the adjustment worker only has to adjust the relevant portion according to the output value of the device, and the adjustment work is greatly simplified. Further, if the device for physically adjusting the corresponding adjustment point is provided as in the second aspect of the invention, there is also an effect that the adjustment work can be automated.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a filter adjusting apparatus according to an embodiment of the present invention.

FIG. 2 is a vector diagram of reflection coefficients of the filter (microwave bandpass filter) shown in FIG.

FIG. 3 is a flowchart of a processing algorithm of the arithmetic device.

FIG. 4 is an equivalent circuit diagram of the filter (microwave bandpass filter) shown in FIG.

FIG. 5 is a configuration block diagram of a filter adjustment device according to another embodiment of the present invention.

FIG. 6 is a configuration block diagram of a conventional filter adjustment device.

7 is a scalar diagram of the reflection coefficient of the filter (microwave bandpass filter) shown in FIG.

[Explanation of symbols]

 1 Microwave bandpass filter 2 Vector network analyzer 3 Computing device 4 Adjustment screw rotation mechanism 5 Adjustment screw 7 Human eye 8 Human hand

Claims (2)

[Claims] 1. A reflection coefficient as viewed from an input end or a transmission coefficient as viewed from an output end of a filter having one or more adjustment points, which is configured by using a lumped element or a distributed constant element, and A measuring device that measures as vector information over two or more frequency points; and an element in the equivalent circuit that minimizes the difference between the value measured by the measuring device and the value calculated in the equivalent circuit of the filter. A filter adjustment device comprising: a calculation device that calculates a state value and determines an adjustment direction and an adjustment amount of a corresponding adjustment point of the filter so that the state value matches a target value. 2. The filter adjusting device according to claim 1, further comprising: a device that physically adjusts a corresponding adjusting portion of the filter based on a calculation result of the calculating device.