SU1584103A1 - Readjustable generator - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to expand the frequency range of the generated signals and increase stability in the frequency range. Tunable oscillator contains controlled oscillator 1, directional coupler 2, band-pass filter 3, discriminator 4 with molecular frequency reference, phase detector 5, intermediate-frequency amplifier 6, synchronous detector 7, low-frequency generator 8, phase modulator 9, frequency synthesizer 10 , adder 11, DC amplifier 12, adjustable phase shifter 13. The discriminator 4 at the same time contains a gas cell 14 and an amplitude detector 15. The discriminator 4 is used to automatically adjust the frequency of the formed cola baths on the side component of the modulated oscillation of the controlled oscillator 1, the spectrum of which contains three frequency components that are separated from each other by the frequency F e of the synthesizer 10. The frequency tuning of the controlled oscillator 1 is carried out by tuning the frequency of the synthesizer 10. to a smooth frequency tuning of the controlled oscillator 1. 1 sludge.

Description

31

I The invention relates to radio engineering and can be used in radio measuring technique and experimental physics in generating oscillations in the millimeter and submillimeter wavelengths.

The aim of the invention is to expand the frequency range of the generated signals and increase stability in the frequency range.

The drawing shows a structural electrical circuit of a tunable generator.

Tunable generator contains controlled oscillator 1, directional coupler 2, band-pass filter 3, discriminator 4 with molecular frequency standard, phase detector 5, intermediate frequency amplifier 6, synchronous detector 7, low-frequency generator 8, phase modulator 9, a frequency synthesizer 10, an adder 11, a direct current amplifier (CNT) 12, an adjustable phase shifter 13. The discriminator 4 with the molecular frequency standard contains a gas cell 14 and an amplitude detector 15.

Tunable generator operates as follows.

The discriminator 4 is used to automatically adjust the frequency of the generated oscillation by the side component of the modulated oscillator to be controlled by the controlled oscillator 1..

f.

fr - f

WITH

The frequency fr is modulated with a Malm modulation index with a frequency fc of the synthesizer 10 through the phase modulator 9 and the adder 11. As a result, the spectrum of the controlled oscillator 1 contains three frequency components spaced apart from each other by the frequency ft, while the lateral components are modulated in frequency using a phase modulator 9 and a generator 8, having a low frequency, which determines the magnitude of the deviation of this frequency modulation. The magnitude of the deviation is chosen to be approximately equal to the width of the absorption line.

Part of the power of the controlled oscillator 1 operating in the microwave frequency range through the directional, i coupler 2 enters the cuvette 14 ". Since the transition frequency fl of the selected gas absorption line satisfies the ratio fА fr - fe, one of the side components of the frequency-modulated controlled radiation generator 1 is absorbed by the gas. In the result, amplitude modulation appears in the output signal of cuvette 14, and a signal at frequency fc appears at the output of amplitude detector 15. This signal, proportional to the intensity of the absorption line, is amplified by IFC 6 and is fed to the first, the input of the synchronous detector 7, to the second input of which the frequency modulator frequency fcc signal 9 arrives. The signal

five

0

five

0

five

from the output of the synchronous detector 7, also proportional to the intensity of the absorption line, but transferred downward in frequency, goes to the first input of the phase detector 5, to the second input of which a low frequency signal from the generator 8 is fed through the controlled phase shifter 13.

In the phase detector 5, the phase detection of the frequency-modulated signal is performed and the signal at its output is proportional to the deviation of the frequency Ј g - fc from the frequency fl of the center of the absorption line. This signal is amplified by the DCF 12 and is fed to the adder 11, the output of which affects the frequency of the controlled oscillator 1 so that there is no signal at the output of the phase detector 5. This means that there is an automatic frequency tuning of the lateral radiation component of the controlled generator 1 according to the selected gas absorption line. The output radiation of the controlled oscillator 1 thus stabilized through the directional coupler 2 is fed to the input of the band-pass filter 3. Since the band-pass filter 3 is tuned to the frequency fr, it

® filters the lateral components of the radiation of the controlled oscillator 1, as a result of which the output signal of the tunable oscillator has one highly stable frequency fr. Tuning the frequency fr of the controlled oscillator 1 is performed by tuning the frequency fu of the synthesizer 10, due to the fact that the side component

the microwave radiation of the controlled oscillator 1 is captured in frequency, the smooth tuning of the frequency of the synthesizer 10 leads to the smooth tuning of the frequency fr of the controlled oscillator 1.

Claims (1)

Invention Formula A tunable oscillator containing a serially connected controlled oscillator, a directional coupler, a molecular frequency discriminator and an intermediate frequency amplifier, a phase detector and a DC amplifier connected in series, as well as a low frequency generator and a band-pass filter whose output is connected to another directional output the answer is tel differing in that that, in order to expand the frequency range of the generated signals and increase stability in the frequency range, serially connected frequency synthesizers, a phase modulator and an adder, as well as an adjustable phase shifter and a synchronous detector, the first and second inputs and output of which are connected, are introduced frequency, to the output of the phase modulator and to the first input of the phase detector, the second input of which is connected to the output of the adjustable phase shifter, the input of which is combined with the second swing phase modulator and connected to the output of the low frequency, the second input and the output of the adder are respectively connected to the output of the DC amplifier and to the input of the controllable oscillator.