SU1282023A1 - Device for measuring parameters of microwave elements - Google Patents

Abstract

The invention relates to radio measurements. The purpose of the invention is to expand the upper limit of the frequency range and increase the accuracy of measurement of phase parameters. The device contains Mr-1 oscillating frequency, three directional couplers 2-4, detector 5, two local oscillators 6 and 18j block 7 of automatic frequency control, a head of 8,9,15 and 16, two power splitters ( DM) 10 and 17, two mixers 11 and 12, two balanced mixers (BS) -13 and 14, band-pass filter (PF) 19, microwave switch 20, matched load 21, investigated microwave el-22, indicator 23, a variable attenuator 24 and a segment 25 of the transmission line of variable length. The goal is achieved by the introduction of BS 13 and 14, DM 17, local oscillator 18, PF 19, attenuator 24 and segment 25, which provides a calibration process for the transmission parameters. In this process, the equal amplitudes of the signals arriving at the inputs of the reference and measuring channels of the indicator 23, and the equal phase shifts of these signals are achieved. The apparatus according to claim 2 of the invention is characterized by the implementation of a local oscillator 18. 1 Cp. f-ly. 2 Il. C (L

Description

The invention relates to the technique of radio measurements and can be used in measuring the parameters of the devices of the millimeter range.

The purpose of the invention is to expand the upper limit of the frequency range and improve the accuracy of measuring the azov parameters.

FIG. 1 shows a structural electrical diagram of a device for measuring parameters of microwave elements; in fig. 2 - structural electrical circuit of additional local oscillator ..

A device for measuring parameters of microwave elements contains a oscillating frequency generator 1, first, second and third directional couplers 2, 3 and 4, detector 5, local oscillator 6, automatic frequency control unit 7, first and second isolating elements 8 and 9, divider 10 power, the first and second mixers 11 and 12, the first and second balanced mixers 13 and 14, the third and fourth decoupling elements 15 and 16, additional power divider 17, additional local oscillator 18, band-pass filter 19, microwave switch. 20, matched load 21, we investigate nd microwave element 22, the LED 23, a variable attenuator 24, a variable length segment 25 of the transmission line, the first and second generators 26 and 27 of the microwave signal, an additional microwave switch 28, additional matched load 29.

A device for measuring the parameters of the microwave elements works as follows.

In the calibration mode, instead of the microwave element 22 under study, the microwave element 22 is turned on with a single matrix.

scattering L O 1 J, microwave switch 20 is set to a position at which the transmission parameters are measured. (When calibrated by the reflection parameters, a short-circuited load is connected to the input of the main channel of the directional coupler 4). Using the second microwave switch 28, the output of the first generator 26 of the microwave signal is connected to the balanced mixers 13 and 14.

In this case, from the output of the generator 1 to the input of the blender mixer 13

A measurement signal is received, part of which is coupled by the directional coupler 2, and through the main channel of the directional coupler 3 is fed to the attenuator 24. The output power of the generator 1 is provided by an automatic power control circuit (AME) including the directional coupler 3 and the detector 5.

After passing the attenuator. 24 and section 25 of the microwave signal is fed to the input of the mixer 11, to the second input of which a signal is supplied from the local oscillator 6.

As a result of frequency conversion, a reference signal is generated at the output of the mixer 11.

To the second input of the balanced demounter 13 receives a signal from the output of the additional local oscillator 18.

As a result of the frequency conversion of the measuring signal with the subsequent signal using the band-pass filter 19 of the sum-frequency signal to the microwave element 22 under study, the main channel of the third directional coupler 4 is given a signal which, after passing through

The microwave element 22 with a single scattered matrix receives an additional phase shift P1, due to its specific electrical length.

As a result of the inverse frequency conversion of this signal in the second balanced mixer 14, a differential frequency signal is produced at its output, separated by the transmission path, standing after the balanced mixer 14.

At the same time, the electric transmission path length from the second output of the power divider 17 to the second input of the balanced mixer 14 is performed on A. .. / 2 is longer than the electric transmission path from the first output of the power divider 17 to the second input of the balanced mixer 13 (ArQ - wavelength additional local oscillator signal 18).

After the second frequency conversion in mixer 12, the input of the measuring channel of the indicator 23 receives a signal

) E p-COs (, - u) r) t ,, -. L ,.

where tOp - the frequency of the signal generator 1;

frequency, local oscillator signal; phase shift of the microwave element with a unit scattering matrix; the phase shift of the signal is hetero- .5

homeland 6; signal amplitude.

By selecting an appropriate ratio of the electrical lengths of the transmission paths from the local oscillator 6 to the inputs of the mixers 11 and 12, the phase shifts of the local oscillator signal and the oscillating frequency generator signal supplied to the mixers 11 and 12 are achieved with different signs.

By adjusting the attenuator attenuation 24, the amplitudes of the signals arriving at the inputs of the reference and measuring channels of the indicator 23 are equal, and by adjusting the electrical length of the transmission line section 25, the phase shifts of these signals are equal.

This completes the calibration process for the transmission parameters. Calibration using reflection parameters is similar. In this case, a short-term locking load is connected to the output of the directional coupler -4, and the microwave switch 20 is set to the position corresponding to the measurability of measuring the reflection parameters.

In the process of measuring the microwave element 22 with a single scattering matrix, it is replaced with the microwave element 22 under study. In this case, the input of the measuring channel of the indicator 23 receives a signal containing information about the amplitude and phase parameters of the microwave element 22 under study:

t) E (,,) t +

tzr

 rj,

where jSH M - weakening (more)

and the phase shift introduced by the microwave element under study 22.

Isolation and processing of the measurement information about the amplitude and phase parameters of the microwave element 22 under study is carried out in the indicator device 23, to the control input of which a voltage is applied that controls the frequency tuning of the frequency 282023

 . five

ten

is

20

25

thirty

: $ 5

40

45

50

55 Nerator 1, to provide a panoramic mode of operation of the indicator 23 ..

Claims (2)

1. A device for measuring parameters of microwave elements, comprising a oscillating frequency generator, the first output of which is connected to the input of the main channel of the first directional coupler connected by the output of the secondary channel to the input of the main channel of the second directional coupler whose output of the secondary channel is connected through the detector to the control the input of the oscillating frequency generator, an automatic frequency control unit, the output of which through the local oscillator is connected to the input of a power splitter They are connected correspondingly to the first inputs of the first and second mixers, the output of the first mixer is connected to the input of the automatic frequency control unit and the reference input of the indicator, the measuring input of which is connected to the output of the second mixer, and the control input to the second output of the rocking generator — frequencies, the third directional coupler, the primary channel output of which is an output for connecting the input of the microwave element under study, and the output of the secondary channel through a microwave switch with a matched load It is characterized in that, in order to expand the upper limit of the frequency range and improve the accuracy of measuring phase parameters, an additional local oscillator, an additional power divider, the first balanced mixer and a bandwidth drive, the output of which is connected to the input of the main channel of the third directional channel, are introduced into it the coupler, between the second output of the additional power splitter and the second input of the second mixer, the second balanced mixer, the second input of which is connected to the second the output of the microwave switch, between the output of the main channel of the second directional coupler and the second input of the first mixer, in series B1, is a variable attenuator and a length of transmission line of variable length, while the second input of the first, balanced mixer is connected to the output of the main channel of the first 5-12202023 the second coupler, and the second input of the microwave switch body is the input for connecting the output of the microwave element under study. 2. The device POP.1, different a-5 You need it because the additional local oscillator consists of the first and second microwave signal generator, the outputs which are connected to the first and second inputs of the additional microwave switch, the first output of which is connected to the input of the additional matched load, the second output of the additional microwave switch is the output of the additional local oscillator. 26 28 K 17 FIG. 2