SU964964A2 - Two-phase infralow frequency generator - Google Patents

Description

(54) TWO-PHASE INFRANIZED FREQUENCY GENERATOR

1 The invention relates to radio engineering.

According to the main author. St. No. 633130 is known a two-phase infra-low frequency generator comprising a series-connected phase control unit, a first frequency divider, a first low-pass filter, a first mixer and a first output low-pass filter sequentially connected a second frequency divider, the input of which is connected to the output of the phase control unit, the second filter low pass, the second mixer and the second output low pass filter, a reference crystal oscillator, the outputs of which are connected to the other inputs of the first and second dividers h frequency range pulse generator, as well as the third frequency divider and / third low-pass filter serially connected, the output of which is connected to the other inputs of the first and second mixers, and a comparison unit is entered between the output of the reference quartz pulse generator and the input of the third frequency divider -.

2

pogo connected to the output of the pulse generator 1.

However, this device has an insufficiently pure spectrum and an insufficiently wide frequency range of output signals.

The purpose of the invention is to increase the purity of the spectrum and expand the frequency range of the output signals.

The goal is achieved by introducing a series-connected gate generator, a pulse-phase detector, a memory device and a control element into the two-phase infra-low frequency generator between the output of the range pulse generator and the input of the reference quartz oscillator, while the output of the reference quartz oscillator is connected. to the input of a pulse-phase detector.

The drawing shows a structural electrical circuit of the proposed device.

Claims (1)

The two-phase infra-low frequency generator includes a phase control unit 1, the first v frequency divider 2, the first low pass filter 3 3, the first mixer 4, the first low pass output filter 5, the second frequency divider 6, the second low pass filter 7, the second mixer 8 , second output low-pass filter 9, reference crystal oscillator 10 pulses, range pulse generator 11, third frequency divider 12, third low pass filter 13, comparison unit 14, gate generator 15 pulse-phase detector 16, storing stroystvo 17 and control member apparatus operates as follows. The first, second, and third dividers 2, 6, and 12 have the same coefficient of division N. In the initial state, the comparison unit 14 is open and the inputs of the first, second, and third dividers 2, 6, and 12 are received by the pulses of a reference crystal oscillator 10. The output signals of the dividers frequencies with a frequency of fon / N are fed to filters 3, 7, and 13, which transmit the first harmonic, and are further converted into mixers 4 and 8. Conversion products pass through output filters 5 and 9, which separate the difference frequency of the input signals of mixers 4 and 8. Upon admission to Comparison 1 4 one prohibitory impulse of the range generator 11, the comparison unit H is closed for the duration of the passage of one impulse of the reference crystal oscillator 10. Thus, the individual impulses with a repetition frequency of the inhibitory pulses, which must be less than the frequency of dividers 2, are excluded from the pulse sequence of the reference quartz generator 10 6 n 12. This exclusion of pulses causes a continuous phase shift of the output signal of the third filter 13 with jumps in -yr due to the discrete time delay of the output signal The third splitter 12 and the appearance in the spectra of the output signals of mixers 4 and 8, the components with the angular velocity fl 2j / fon / These components are extracted by the output filters 5 and 9 and are the output signals of the device. Phase set-up is performed by phase control unit 1, which gives a pulse to the initial zero setting of dividers 2, 6 and 12, after which it controls the number of pulses input to one of dividers 2 or 6, which allows a discrete phase signal to be set at the output of the device. a shift from O to 360 °, a multiple of a single phase jump of 2M / N. It is convenient to choose N multiple of 360 At N 360 °, the established phase shift is numerically equal to the number of pulses excluded by phase control unit 1. However, in practice, the frequencies of the reference crystal oscillator 10 and range oscillator 11 are asynchronous and have their own instability, the suppression of pulses at the output of the comparison unit 14 is not can occur at regular intervals of time, so the signal at the output of the third filter 13 has a parasitic phase modulation. This type of modulation is dangerous in that the spectrum of modulation functions can appear slow para-. siting components falling into the passband of output filters 5 and 9. The amplitude of spurious components is directly proportional to the division ratio and the required suppression is achieved by selecting N, which causes the instantaneous stability of the output signals to deteriorate when it is impossible to select sufficiently large N values, limits the range spacing on the output signals towards higher frequencies. The shaper 15, the pulse phase detector 16, the storage device 17 and the control element 18, together with the reference crystal oscillator 10 and the band oscillator 11, form a pulse phase locked loop (IFAPH), which synchronizes the reference crystal oscillator 10 relative to the band oscillator 11, which eliminates the appearance of slow parasitic phase modulation, improves the instantaneous frequency stability of the output signals, increases the purity of the spectrum, and widens the frequency output range. The required suppression of high-frequency components occurs at lower values of N. Thus, the proposed device allows narrowing and ordering the spectrum of output signals, expanding the range of output frequencies, and reducing filtering requirements. The invention is a two-phase generator of infra-frequency frequencies by author. St. N ° 633130, characterized in that, in order to increase the purity of the spectrum and to expand the frequency range of the output signals, between the output of the range pulse generator and the input of the reference quartz pulse generator, serially connected gate driver, a pulse-phase detector, a memory device are inserted .59649646 and control element, with output information sources, reference quartz oscillator generator taken into account during the examination also connected to the input .pulse-phase-i. USSR Author's Certificate M 633130, go detector.kl. H 03 H 21/02, dated 11/29/76 (prototype).