SU1478141A1 - Device for variable frequency peak microwave power value metering - Google Patents

Abstract

This invention relates to a measurement technique. The purpose of the invention is to improve the accuracy and speed of measurements. The device contains a ferrite converter 1 with an electromagnet 2, a low-pass filter 3, a modulator 4, a calibrator 5, a magnetic system tuning unit 6, a converted signal processing block 7 consisting of a high-pass filter 8, an attenuator 9, a converted signal amplifier 10 and a peak detector 11, interfacing unit 12, frequency converting unit 13, matched load 14, frequency modulator 16 and phase shifter 17. For device frequency selective peak value, the microwave signal in the device is not only modulated External Expansion constant magnetic field transducer 1, but at the same time by the same law and the frequency of the microwave oscillation input to a modulator 16. The objective is achieved by using a single modulation frequency biharmonic interacting signals providing temporary "assigning a" signals, i.e. allows to achieve the state of ferromagnetic resonance, namely the state of stable tuning of the device to a certain frequency, without the use of automatic frequency control systems. 1 il.

Description

The invention relates to measuring technique of microwave frequencies and can be used in automated systems for monitoring peak power and frequency of microwave generators for various purposes.

The aim of the invention is to improve the accuracy and speed of measurements. ’

The drawing shows a structural electrical diagram of a device for selective frequency-frequency measurement of the peak value of the microwave power.

A device for frequency-selective measurement of the peak value of microwave power includes a ferrite converter 1 with an electromagnet 2, a low-pass filter 3, a modulator 4, a calibrator 5, a magnetic system tuner 6, a converted signal processing unit 7, consisting of a high-pass filter 8 connected in series, attenuator 9, the converted signal amplifier 10 and the peak detector 11, the interface unit 12, the frequency conversion unit 13, the matched load 14, the input line 15, the frequency modulator 16, the phase shifter 17, stroke 18 for communication with an external control unit, I9 output for connection with an external readout unit and the outlet 20 for the external synchronization.

A device for frequency selective selective peak value of microwave power is as follows.

On command from an external control device (input 18) supplied to block 12, an analog signal (control voltage Uunp) is generated, which enters block 6 ”. At the same time, the corresponding stable current value is generated at the output of block 6. The value of the tuning current at ferromagnetic resonance is proportional to the frequency of the converted microwave signal. This circumstance makes it possible to measure the frequency of the converted microwave signal.

The current entering the electromagnet 2 of the ferrite converter 1 sets the latter to a specific frequency. Adjustment of the tuning frequency is carried out either according to a certain program (in automatic mode), or by the formation of separate control commands that determine a strictly fixed frequency setting (in manual mode). Monitoring the steady-state value of the tuning frequency is carried out by indicating the signal from the output of block 13, to the input of which a frequency-informative signal from block 6 is supplied.

The converted signal at twice the modulation frequency 2F, proportional to the power of the microwave signal, comes from the ferrite converter 1 to block 7, where it is amplified, detected, and through block 12 it goes to an external reading device (output 19) or to the data acquisition and processing system of an automated complex,

To convert the power of microwave signals, the ferrite converter 1 can be used in the mode of harmonic modulation of the resonant frequency of the ferrite resonator or the frequency of the microwave signal - cross-multiplication mode.

I

In either case, the achievement of ferromagnetic resonance in the automatic mode is possible only with the help of a special system of automatic frequency adjustment, which captures and holds the studied microwave signal.

A distinctive feature of the device for the frequency-selective measurement of the peak power of the microwave signal is that for the frequency-selective peak-value of the peak power of the microwave signal, it modulates not only the external constant magnetic pope of the ferrite converter 1, but at the same time by the same law frequency modulator 16 modulates the frequency of the microwave oscillation supplied to the input line 15.

A single frequency biharmonic modulation of the interacting signals allows reaching the state of ferromagnetic resonance, i.e. the state of stable tuning of the device to a specific frequency, without the use of automatic frequency adjustment systems.

In other words, for any value of the external constant field H _with ·, and hence the frequency U; = H _o; a ferrite resonator included in the composition of the ferrite converter 1, ferromagnetic resonance is possible if a microwave signal of the same frequency co arrives at the input of the ferrite converter 1; , frequency-modulated according to the same law as the natural frequency of a ferrite resonator.

The initial phase of the microwave oscillation & ₀ can be arbitrary, since the ferrite resonator is under the action of an external constant magnetic field H. , can be considered as a coherent source of oscillations. Due to this, when the ferrite converter 1 is in operation, ferromagnetic resonance arises from the interaction of the frequency modulated oscillation of the studied microwave signal and the oscillation of the ferrite resonator single-phase with it. A constant phase incursion in the modulating oscillation circuit is compensated by a phase shifter 17.

The source of the modulating oscillation is modulator 4. The signal from it enters through the filter 3 to the frequency modulator. 16, modulating microwave signals, and to a ferrite converter 1.

From the output of the calibrator 5, a signal with a frequency of 2F is fed to a ferrite converter 1 and is used for calibration.

The second output of the ferrite Converter 1 is loaded on a matched load 14.

With a command coming from an external control device (input 18) to block 12, commands are generated at the inputs of the control signals of the latter, which are sent to modulator 4 and attenuator 9 and allow to implement all operating modes. In particular, the control mode of the modulator 4, block 6 and amplifier 10 is implemented by switching analog signals coming from them to block 12 and to the external output of the latter.

I

In preparatory modes (setting modes 0 and gain of the measuring path), error signals are sent from block 12 to amplifier 10 and to the peak detector

II on the corresponding chains.

The signal that performs internal synchronization is generated in block 1 2 and arrives at peak detector 1 1.

Ferrite Converter 1 is designed for primary frequency selective conversion of power and frequency of microwave signals supplied to input line 15 into radio signals with the same envelope. Moreover, from the signal spectrum at the output of the ferrite converter 1, connecting with block 7, a component with a frequency of 2F is used, the amplitude of which is proportional to the peak power of the microwave signal.

To ensure the operation of the ferrite converter 1, it is supplied with: a modulation voltage of frequency F from modulator 4 through filter 3; adjustment current from block 6; the studied microwave signal, pre-modulated by a frequency modulator 16; 2F calibration voltage from calibrator 5 (in calibration mode).

The basis of the ferrite converter 1 is a segment of a symmetrical strip transmission line with a magnetic detector inside it - a spherical ferrite resonator surrounded by a spiral coil from a microwire - and located in the field of an external electromagnet 2. Using the latter, the ferrite resonator is tuned to the frequency of the ferromagnetic resonator, at which and the conversion of electromagnetic waves

When tuning the ferrite converter 1 by an external field to the frequency of the microwave signal, an alternating voltage on the coil of the magnetic detector leads to the appearance of nutation oscillations of the magnetization vector of the ferrite resonator and, as a result, induced EMF. At the same time, in the region of the magnetic detector, there are nutation oscillations of the longitudinal component of the magnetic flux of the microwave signal under study, created by the frequency modulator 16. The mutation oscillations of the interacting secondary fields are in phase and provides ferromagnetic resonance. I

The magnitude of the induced EMF, the spectrum of which contains harmonically the modulation frequency F, is proportionally supplied to the voltage of block 5 by the square of the microwave magnetic field strength or the microwave signal power. The last signal in the form of radio pulses with a carrier frequency of 2F and an amplitude proportional to the power of microwave oscillations passes through a filter 8, which delays the powerful signal from modulator 4 _at frequency F, and the amplifier input, 1 0 „

In calibration calibration mode, a magnetic detector of ferrite converter 1 is supplied. At the same time, a modulating signal of frequency F from block 4 is not supplied. Next, the calibration signal from the magnetic detector enters block 7 about

Block 12 is designed to convert control commands provided. 10-bit binary parallel code (WPC) to input 18 from an external control device into analog commands, which provide: choice of operating mode, setting of the tuning frequency, connection to control functional units.

Block 1'2 is also intended for automatic adjustment of zero to the output of block 11 and the gain of the measuring channel.

The positive effect of using the device for frequency selective selective peak power of the microwave signal is to increase the accuracy of the frequency measurement and ensure the stability of the tuning for the microwave signal:

due to the use of biharmonic modulation of interacting signals, providing a temporary reference ”signals and excluding the use of unstable automatic frequency control system;

by increasing the sensitivity of the capture of the microwave signal.

The effect of using the invention also lies in increasing the accuracy of measuring the peak value of the power of the microwave signal by increasing the conversion coefficient of the ferrite converter 1; to increase the speed of the measurement process due to the timing of the interacting signals and due to the high resolution of the peak detector 11; in expanding the lower part of the dynamic range by increasing the coefficient

II conversion of the ferrite converter 1 and by increasing the sensitivity of signal capture in the automatic mode;

in simplifying the design of eliminating from it a system of frequency frequency adjustment.

Claims (1)

A device for frequency-selective measurement of the peak value of the microwave power, containing a ferrite converter, an electromagnet connected to it, the first input of the ferrite converter is connected through a low-pass filter to the output of the modulator, the second input is connected to the output of the calibrator, the electromagnet winding is connected to the first output of the tuning unit of the magnetic system , the first output of the ferrite converter is connected to the input of the converted signal processing unit, consisting of a series-connected filter of the upper hour from the attenuator, the converted signal amplifier and the peak detector, the output of which is connected to the first input of the interface unit, the second input of which is connected through the frequency conversion unit to the second output of the tuning unit of the magnetic system, the third input of the interface unit is an input for connecting an external control unit, the first output the interface unit is connected to the control input of the converted signal amplifier, the second output is to the input of the tuning unit of the magnetic system, the third and fourth outputs are to the control inputs modulator and calibrator, respectively, the fifth and sixth outputs are to an external reading unit, the second output of the ferrite converter is connected to the matched load, characterized in that, in order to improve the accuracy and speed of measurements, the third input of the ferrite converter is connected to the output of the introduced frequency modulator, the first the input of which is the input of the device, and the second input is connected to the output of the low-pass filter through the introduced phase shifter, the seventh additional output of the interface unit is connected to directs the input of the peak detector.