SU103040A1 - The method of measuring the frequency in the ultrashort wave range using a short wavelength heterodyne wavemeter - Google Patents

Description

Increasing 1) the resolution of the frequency response of measuring devices is one of 113 important tasks of measuring equipment.

Nowadays, for changing 1) frequencies, widespread heterodyne wavemeters are designed to work in certain radio frequency bands, for example, in the short wave range, in the ultrashort wave range, etc. Frequency comparison with these wave meters is done but -Method " Zero beats, in which the paste region is limited by a band of ± 10 KHz, determined by the audibility of difference frequencies.

The proposed method of measuring the frequency in the ultrashort-wave range is based on the gain of the birthmark of the short-wavelength range meter and makes it possible to decorate the tuning area to ± ktz.

This method of matching frequencies consists in the following: a frequency difference between the frequency of the tested ultrashort wave generator and the corresponding harmonic of the short-wave heterodyne wavemeter, received at the output of this wavemeter, is fed to the amplifier and then, already amplified, modulated by a low frequency, for example, 1000 Hz, local modulation generator.

The modulated differential frequency voltage is applied to a low-pass filter tuned to a frequency

1000 HZ. This filter is applied in order to delay the modulation frequency in the absence of the difference frequency. After the filter, the modulated differential frequency signal is applied to the detector. The selected modulation frequency (1000 Hz) at the detector output is amplified and then fed to the cathode repeater, to the output of which is connected an ultrasonic transducer device — a telefop or an oscilloscope.

(The measurements according to the proposed method are shown in Fig. 1, where (1) is a generator, whose frequency is measured, (2) is a short-wavelength heterodyne wave meter, (3) is a measuring path, and (4) is shd 1kator.

An 11pp coincidence is compared, 1x frequencies (frequencies of the tested oscillator and harmonic of the heterodyne wavemeter) at 1) the frequency of 1000 Hz at the output of the ir.i-meter path will be minimal.

P)) and the difference in sp of these frequencies and an increase in the difference frequency to approximately 150 KHz, the voltage modulation frequency (1000 Hz) allocated at the detector output will also increase. With a further increase in the difference frequency of its passage in the polymer path, it will worsen and the voltage on its output will decrease.

Thus, the moment of coincidence

-comparable frequencies ol1) e. heltz-s but mippumumu pru-thii frequency modulus

(1000 Hz) concluded between two

maxima, corresponding to the difference between 1FM frequencies, P) L1-dimensionally + 100 kHz, as shown in FIG. 2

Subject invention

The method of measuring the frequency in the ultrashort-wavelength range with a heterodyne wavelength indicator of short-wavelength Dianazone, which is tl icch aa

that, in order to expand the difference between the compared frequencies to + 100–200 kHz, the difference frequency at the output of the heterodyne wavemeter is modulated by a low fixed frequency with resonant frequency voltage gain amplification.

WOO - l / kHz PP / 1 transmission

FIG. 2 + Af KSt4