JP2906822B2 - Bandpass filter characteristic adjustment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bandpass filter characteristic adjustment method, and more particularly to a bandpass filter (hereinafter, referred to as DR filter) characteristic adjustment method using a dielectric resonator.

2. Description of the Related Art A conventional DR filter waveform adjustment method is as follows.
The microwave is input to the DR filter and the frequency-level characteristics of the return loss waveform are measured.

FIG. 5 is a block diagram showing an example of the prior art. An input microwave a is generated by the sweep oscillator 1, passes through the directional bridge 2, and is input to the DR filter 3. The passing microwave b is output from the DR filter 3 and input to the network analyzer 4. On the other hand, part of the input microwave a becomes a return loss c, passes through the directional bridge 2, and is input to the network analyzer 4. The network analyzer 4 displays the frequency-level characteristics of the return loss c on the screen of the network analyzer 4. The human looks at the frequency-level characteristics of the return loss c displayed on the screen of the network analyzer 4 to judge the waveform intuitively, rotates the adjustment screw, and adjusts it so that it falls within a predetermined standard.

FIG. 6 shows obtained frequency-level characteristic data. The vertical axis represents the return loss gain (dB), and the horizontal axis represents the frequency (Hz).

In the above-described conventional DR filter characteristic adjustment method, a skilled worker intuitively judges a waveform with respect to frequency-level characteristic data, rotates an adjustment screw, and adjusts a predetermined standard. Had been adjusted to become. As described above, when the adjustment is performed by human judgment, a large amount of labor is required, and there is a disadvantage that it takes time to get used to the adjustment process.

According to the DR filter characteristic adjusting method of the present invention, (A) a microwave is supplied to a band-pass filter using a dielectric resonator, and a return loss frequency which is one of characteristic waveforms is obtained. Means for measuring level characteristics,
(B) the return loss frequency - level characteristics means asking you to error amount of the theoretical characteristics, to minimize the (C) the amount of error
Means for selecting an adjustment screw so that (D) the selected
Means for automatically adjusting the screw by rotating the adjusting screw; and (E) means for selecting the adjusting screw so as to minimize the error amount and varying the screw rotation amount in accordance with the variation in the error amount when rotating. It consists of.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
An input microwave a is generated by the sweep oscillator 1, passes through the directional bridge 2, and is input to the DR filter 3. An output microwave b is output from the DR filter 3,
Input to the network analyzer 4. On the other hand, part of the input microwave a becomes a return loss c, passes through the directional bridge 2, and is input to the network analyzer 4.
The frequency of the return loss c by the network analyzer 4-
A two-dimensional data signal d having a level characteristic is generated and taken into the microcomputer 5. Microcomputer 5
After calculating the error amount, the operator selects a screw and instructs the mechanism control unit 6 which screw to rotate and how much. Under the control of the mechanism control unit 6, the mechanism unit 7 rotates the adjustment screw of the DR filter 3.

FIG. 2 is a return loss frequency-level characteristic diagram showing a method of calculating an error amount. The waveform of the solid line is the measured value, and the waveform of the dotted line is the theoretical value obtained from the equivalent circuit. Now, consider a sampling point where the frequency axis is the x-axis, the return loss gain axis is the y-axis, and the x-axis is equally divided into n. x = xq
At two points A (x
q, yp) and B (xq, yt), and the distance between the two points at this time is It is represented by When the sampling point x is n points from x0 to xn, and the sum of the distance between the coordinates of the theoretical value and the measured value is included as an error amount, the error amount is represented by the following equation.

FIG. 3 is an operation flowchart of the automatic adjustment. The two-dimensional data is input by means P1, and FIG.
The error amount described in (b) is calculated. The screw is selected by means P3, and the screw is rotated by means P4. Means P4
When the rotation of the screw is performed, the return loss waveform changes and the two-dimensional data is input again by the means P1 and the means P1
A series of operations from P4 to P4 is repeated. FIG. 4 shows the means P of FIG.
3 is a detailed operation flowchart of FIG. The means P5 reads the error amount, and the means P6 determines whether the error amount is equal to or less than a specified value. If the error amount is equal to or less than the specified value (Y), the means P21
Then, the repetitive operation is stopped and the adjustment is terminated. When the error amount is equal to or larger than the specified value (N), the means P7 determines whether flag = 1. The value of this flag is f as an initial value.
It has lag = 0 and is changed by means P17 and means P20 and is used to determine the movement of the screw. Flag =
If it is not 1 (N), the means P8 judges whether the error amount of the previous time is equal to the current error amount, and if it is equal (Y), it goes to the means P14.
If not equal (N), go to means P9. F by means P7
If lag = 1, the process proceeds to the means P18.

In the means P14, each time the variable count is passed, the value is increased by one. In the means P9, it is determined whether or not the variable count is equal to or more than a specified value. If the variable count is less than the specified value (N), the means P10 determines whether or not the error amount has decreased. When the variable count is equal to or more than the specified value in the means P9 (Y), the process proceeds to the means P18. If the error amount is reduced by the means P10 (Y), the process proceeds to the means P11, proceeds to the means P12 without moving the screw, and inserts the screw for 1 STEP × count.
The error amount is stored by means P13.

If the error amount has not decreased in the means P10 (N), the operation proceeds to the means P15, and the movement of the means P
16 screws are returned by 1 STEP × count. Next, means P
In step 17, flag = 1 is set, and the error amount is stored in the means P13. In the means P18, it moves to the next screw and the means P
At step 19, screw is put in 1 STEP × count, and means P20
To set flag = 0, and the means P13 saves the error amount.

As described above, according to the DR filter characteristic adjustment method of the present invention, the skilled worker judges whether the characteristic is good or not from the frequency-level characteristic, and instead, the microcomputer uses the frequency characteristic which is one characteristic of the DR filter. There is an effect that the amount of error between the theoretical value and the measured value at the sampling point of the level characteristic is calculated, and the DR filter can be automatically adjusted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 shows a return loss frequency according to an embodiment of the present invention.
It is a level characteristic diagram.

FIG. 3 is an operation flowchart showing one embodiment of the present invention.

FIG. 4 is a detailed operation flowchart of means P4 shown in FIG. 3;

FIG. 5 is a block diagram showing an example of the related art.

FIG. 6 is a return loss frequency-level characteristic diagram showing an example of the related art.

[Explanation of symbols]

 Reference Signs List 1 sweep oscillator 2 directional bridge 3 DR filter 4 network analyzer 5 microcomputer 6 mechanism control unit 7 mechanism unit a input microwave b output microwave c return loss d two-dimensional data signal

Claims (1)

(57) [Claims] (A) means for supplying a microwave to a band-pass filter using a dielectric resonator and measuring a return loss frequency-level characteristic which is one of characteristic waveforms; (B) said return loss frequency Means for calculating an error amount between the level characteristic and the theoretical characteristic ; (C) selecting an adjustment screw so as to minimize the error amount
That means, the hand for automatically adjusting by rotating the adjustment screw in which said selected (D)
Stage, band pass filter, characterized in that it comprises a variable to means, capital in accordance with the variation of the error amount bis rotation amount when the adjustment screw is selected, rotate to minimize (E) the amount of error Characteristic adjustment method.