SU620907A1 - Radio signal frequency meter - Google Patents

Description

one

The invention relates to a radio measuring technique and can be used in systems for automatically measuring the frequency of radio signals.

Multichannel devices for measuring the frequency of radio signals are known, including a frequency sensor, a mixer, a low-pass filter, a square voltage driver, a capacitor converter, a frequency meter and a voltmeter, based on the method of comparing oscillations of an unknown frequency with the oscillations of an exemplary generator 1.

However, such devices are complex.

The closest to the proposed mmo is a radio frequency meter containing a reversible counter, the output of which is connected to the register input, the first pulse shaper and serially connected meter, a low pass filter, the second pulse shaper and the control unit 2.

A disadvantage of this device is the limited range of measured frequencies.

The purpose of the invention is to expand the range of measured frequencies.

This is achieved by including a reversible counter, the output of which is connected to the INPUT register, the first pulse shaper and the serially connected mixer, a low-pass filter, the second pulse shaper, and the control unit, are additionally introduced into the frequency meter of the radio signals; an exemplary frequency generator connected in series, a mixer, a low-pass filter, the output of the first pulse shaper being connected to the input of the first coincidence element and black The first phase shifter is connected in series, the second coincidence element is connected to the first input of the reversible counter, the output of the control unit is connected to the second input of the second coincidence element and connected to the second input of the reversible counter through the first matching element, and the second frequency generator output the phase shifter is connected to the second input of the first mixer, the input of which is connected to the second input of the second mixer.

The drawing shows the structural electrical circuit of the device.

Claims (2)

Measure 1b of the frequency of the radio signals contains a generator of 1 exemplary frequency, a phase shifter 2, s. Mixers 3 and 4, 5 II 6 low-pass filters, an emulsion drivers 7 and 8, a control unit 9, a phase shifter 10, elements 11 and 12 coincidence, a reversible counter 13 and register 14. The radio frequency meter operates as follows. The received signal of unknown frequency Id and the voltage of generator 1 of model frequency a come to mixers 3 and 4. Moreover, the received signal goes to both mixers in phase, and the voltage of the generator goes to first mixer 3 with a phase shift of 1/2. At the outputs of the mixer 3 and 4, as a result of the non-linear conversion of these signals, complex-shaped voltages are generated, containing a large number of combination frequencies. The lowest frequency among them will be the frequency 0) /, w, - and) o, i.e. the detuning frequency is equal to the frequency difference between the received signal and the generator. The voltage of the difference frequency w is allocated by low-pass filters 5 and 6. Moreover, if the frequency ω of the received signal is higher than the frequency from the oscillator, then the voltage of the difference frequency)) Е selected by filters 6 and 5 will be out of phase by -f p / 2, otherwise - on l / 2. Consequently, the phase shift at the difference frequency ω} p varies abruptly by l with a change in the mismatch sign. This makes it possible to indicate a mismatch sign. The detuning is measured using the zero counting method. For this, the output voltages of the filters 5 and 6 are converted to rectangular voltages. Moreover, the voltage of the rectangular shape from the output of the second shaper 7 is converted into a sequence of short pulses appearing at the moments of transition by a zero-level signal with a positive derivative. The resulting short pulses are fed to the inputs of elements 11 and 12 of coincidence, the other inputs of which are supplied with square voltage from the output of the first driver 8. Short pulses appear at the output of that element of coincidence, at the input of which the appearance of pulses coincides with positive value of the rectangular voltage, and their number will be determined by the amount of detuning. At this, the readings of the reversing counter 13 will correspond to the magnitude and sign of this detuning and are recorded by register 14. Thus, the proposed device allows not only determining the detuning value of the measured frequency of the received signal relative to the generator frequency, but also its sign. The invention of a radio frequency meter comprising a reversible counter whose output is connected to a register input, a first pulse shaping device and a series-connected mixer, a low-pass filter, a second pulse shaper and a control unit, characterized in that in order to expand the range of measured frequencies , it additionally introduces two phase shifters, two coincidence elements and a series-connected generator of exemplary frequency, a mixer, a low-pass filter, the output of the first form a pulse interrupter is connected to the input of the first coincidence element and through the first phase shifter connected in series, the second coincidence element is connected to the first input of the reversible counter, the output of the control unit is connected to the second input of the second coincidence element and connected through the first element of the reversible counter, and the output of the generator of exemplary frequency through the second phase shifter is connected to the second input of the first mixer, the input of which is connected to the second input of the second mixing l. Sources of information taken into account in the examination: 1. USSR author's certificate number 393693, cl. G 01 R 23/10, 1971. 2. USSR author's certificate number 261572, cl. G 01 R 23/10, 1968. & f.aS