SU866694A1 - Frequency divider of harmonic oscillations with countdown of 2:1 - Google Patents

Description

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The invention relates to multiple frequency converters, namely, harmonic frequency dividers.

A regenerative harmonic oscillation frequency divider with a dual frequency converter is known, containing intelligently} reading frequencies in the feedback circuit Til.

However, when dividing the frequency, two such devices do not exclude the possibility of self-excitation of parasitic oscillations at any of the frequencies of the filter passband, since the oscillation frequency at the mixer output tornates an input signal, and at its input in the feedback circuit . In the absence of an input signal, the self-excitation of parasitic oscillations in the TEO scheme is determined by the conditions of balance and amplitudes in the feedback ring, and, if present, by the ratio of the levels of the transformed and non-transformed signals at the mixer output.

The closest one to the present invention is a frequency divider containing a series-connected first mixer, a low-pass filter, an amplifier connected to the first input of the second mixer, and the output of which is connected to the first input of the first mixer through the band pass filter. The input of the divider is connected to the second input of the first mixer and through the phase shifter to the input of the second mixer 2.

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A disadvantage of the known divider is the possibility of spontaneous oscillations spontaneous oscillation at any of the frequencies in the passband of the filters when the input signal is applied due to dissociation. matching phase characteristics of the phase shifter and feedback circuit.

The purpose of the invention is to increase the stability of self-excitation.

The goal is achieved by the fact that in the depot containing the first mixer connected in series, a low-frequency filter, an amplifier connected to the first input of the second mixer, the output of which is connected through a band-pass filter to the first input of the first mixer, the divider input is connected to the second input of the second mixture. and through the frequency doubler with the second input of the first mixer.

In the drawing, the frequency splitter block is represented.

The divider contains the first clip 1, the low pass filter 2, the amplifier 3, the second mixer 4, the band pass filter 5 and the frequency doubler 6.

The device works as follows.

An input signal with a frequency w is fed to the input of mixer 4 and through frequency doubler 6 to input of mixer 1, the output of which is connected to one of the inputs of mixer 4 through filter 2 of low frequencies and between the mixers a band-pass filter 5i is connected. tuned to a frequency of 1.5 to. The 2 low frequencies select the signal in the feedback circuit at a frequency ujy. After mixer 4, the signal of the sum frequency t is released and after mixer 1 the signal of the difference frequency 2 U - (and) + UJ) x) is again fed to mixer 4, t, e, the frequency balance lJJoc - 2 U) - (LW ) where it follows from.

that only the signal ujy can swell in the feedback circuit

Using a frequency doubler in a divider instead of a phase shifter present in a known device makes it much easier and cheaper to: Set the frequency divider setting by automatically maintaining the phase balance in the device in question and eliminating the possibility of edeni self-exclusion at parasitic frequencies.

Claims (2)

1. USSR author's certificate number 5958437 class. H 03 B 19 / OO, 1974 2. USSR author's certificate No. 22J938, cl. H 03 B 19 / OO, 1967G j / V