SU1617385A1 - Panoramic meter of s-parameters - Google Patents

Abstract

The invention relates to radio metering technology and can be used in panoramic meters of complex reflection and transmission coefficients (S-parameters) of quadrupoles in the millimeter-wave range. The aim of the invention is to increase the dynamic range. Panoramic S-parameter meter contains phase detector 1 microwave, indicator 2, generator 3, which contains oscillator 5, frequency attenuator 6 with electric control, dividers 7 and 9, amplitude modulator 8, detector 10 microwave, low frequency detector 11, adder 12 and phase shifter 19 at 90 °. Indicator 2 contains synchronous detectors 13 and 14, analog-to-digital converter 15, control and calculation unit 16 and display unit 17. Due to the 90 ° phase shift between the reference voltage and the voltage of the parasitic amplitude modulation signal, the effect of the latter is eliminated At the output of the synchronous detectors 13 and 14, it becomes possible to change with the help of synchronous detectors 13 and 14 weaker measuring signals in phase with the reference one, which expands the dynamic range of changes. 1 il.

Description

The definition is related to the field of radio measuring equipment and can be used in panoramic meters of the complex reflection and transmission coefficients (S-parameters) of the four-floor fields and in the range of millimeter waves.

The aim of the invention is to increase the dynamic range.

The drawing shows a structural electrical circuit of a panoramic S-parameter meter.

The panoramic S-parameter meter contains a phase microwave detector 1, an indicator 2, a generator 3, a measurement object 4. The generator 3 contains a oscillating frequency generator 5, an electrically controlled attenuator 6, the first divider 7, the amplitude modulator 8, the second divider 9, the microwave detector 10, the low frequency detector 11 and the adder 12.

Indicator 2 contains the first and second synchronous detectors 13, 14, anaa

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logo-digital converter 15, control and computation block 16, display block 17, cathode-ray tube 18, A phase shifter 19 on 90 is inserted between the output of the detector 10 and the input of the detector 11.

Panoramic S-parameter meter works as follows

The microwave signal from the output of the generator 5 through the attenuator 6 is fed to the first divider 7, which is divided into two parts. Part of the signal is modulated in the amplitude modulator 8 by the voltage of low frequency F and passes to the second divider 9, the second part of the output signal of the first divider 7 is fed to the first input of the phase detector 1, Part of the modulated signal from the output of the second divider 9 through the measurement object 4 is fed to the second input phase detector 1. The second part of the modulated signal from the output of the second divider 9 is detected by the detector 10, shifted by phase / by. 90 by a phase shifter 19 and detected by a detector 11 to isolate a constant component proportional to the level of the output signal of the generator 5. This constant component is fed to the first input of the adder 12, to the second input of which the reference voltage Efr is applied to adjust the power levels with an attenuator 6 at the outputs of the generator 3.

The unmodulated microwave signal from the first output of the generator 3 in the phase detector 1 is divided into two equal parts and fed to its detectors in phase, and the measuring amplitude-modulated signal from the output of the measurement object 4 in the phase detector 1 after dividing it in half, goes to its detectors with phase shift 90 °. Due to the phase relationships in phase detector 1, as a result of mixing the non-modulated and AM measuring signals, microwave signals at the outputs of the phase detector l generate signals with frequency and amplitudes proportional to the module of the transmission coefficient of the object 4 multiplied by the sine (on one output of phase detector 1 ) and the cosine (at the other output of the phase detector 1) of the phase shift of the measured transmission coefficient. The signals at the outputs of phase detector 1 contain the necessary data on the measured transfer coefficient of object 4 in a complex form. Synchronous detek-,

the tori 13, 14 serve for allocation

measuring information on a direct current and contain input signal amplifiers with a modulation frequency, their amplitude normalizers with 16 attenuators controlled by the unit, and key synchronous detectors proper, tuned to match the phase of the signals at their inputs with the reference voltage U supplied from

5 of the third output of the generator 3, Analog. A go-to-digital converter 15 converts DC signals with measurement information into digital information signals, which are transferred to block 16. Block 16 controls the operation of the main nodes of the S-parameter panoramic meter, including the frequency and power of the generator 5, performs viiig The tedious and logical operations of the processes of calibration, measurement, processing of its results and their output through block 17 to the screen of the cathode ray tube-18 in digital and graphic form,

0 Before taking measurements from

the second (measuring) output of the generator 3 is turned off by the object 4 and the phase shifter 19 is tuned to the minimum of the signals from the synchronous outputs

The detectors 13, 14. This occurs when the phase of the parasitic amplitude modulation signal at the first output of the generator 3 due to the final filtering coefficient of the system 0 automatic power control differs by 90 ° from the phase of the reference voltage Ug. Then, using block 16, the process of calibrating the panoramic S-parameter meter 45 is carried out and the measurement is taken at the sweep point of indicator 2, which is selectable by a tunable label. The measurement result is displayed on the screen of the cathode ray tube 18 in a digital 50 form.

As a result of a 90 ° phase shift between the reference voltage and the -. By eliminating the parasitic amplitude modulation signal, the influence of the latter at the output of the synchronous detectors is eliminated, which makes it possible to measure with weak synchronous detectors

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measuring signals in-phase with the reference signal, due to which the dynamic range of measurements is expanded.

Claims (1)

Invention Formula Panoramic S-parameter meter containing electrically controlled attenuator, series-connected oscillator, oscillator, first divider, amplitude modulator, second divider, microwave detector, first synchronous detector, analog-digital converter, control and calculation unit, and display unit, second the output of the first divider is connected to the Cv by the first input of the phase detector, the first output of which is connected to the second input of the first synchronous detector, and the second output is connected via the second synchronous detector n to the second input analog-digital the converter, the second input of the second synchronous detector is connected to the detector code of the microwave, the adder. whose input is connected to the output of the low-frequency detector, the output is connected to the control input of the attenuator with electric control, and the receiver input is used to connect the reference voltage source, wherein the control and calculation unit is connected to the control input of the oscillating frequency generator, and the second output of the second divider and the second input The phase detector is an input and output for connecting a measurable quadrupole, characterized in that, in order to increase the dynamic range, A phase shifter was introduced for 90 ,, whose input is connected to the output of the microwave detector, and the output to the input of the low-frequency detector.