SU1370717A1 - Phase-modulated signal shaper - Google Patents

Abstract

This invention relates to radio engineering and reduces non-linear distortion of the output signal. The device contains 1 pulse generator, 2 frequency divider with variable coefficient. division, decoder 3, shaper 4 reverse control signals, reversing shift register 5, al-OR 6, transducer 7 of a sequence of pulses with variable amplitude into a sequence of pulses with constant amplitude, output filter 8. Divider 2, operating in the Libau-Craig code , provides division of the circular frequency Oo of the generator 1 with the coefficient. recalculation of co / cj. Rectangular pulses are formed at its discharge outputs, and a circular frequency of CO is formed at the output. The decoder 3 converts the output signals of the divider 2 in the Liebau-Craig code into a decimal code. 3 il. i (L

Description

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The invention relates to radio engineering and can be used to form phase-modulated signals in monitoring automatic control systems and controlling phase-modulated effects when testing communication and radar devices.

The purpose of the invention is to reduce non-linear distortion of the output signal.

Fig. 1 depicts a structural electrical circuit of a phase modulated signal generator; in fig. 2 is a timing diagram of its operation; FIG. 3 is a graph of a change in the law of modulation of the temporal position of pulses.

The phase-modulated waveform generator contains 1 impulse generator, 2 variable frequency divider (DFD) divider, decoder 3, shaper 4 reverse control signals, reversing shift register 5, element 6, pulse-amplitude-variable transducer 7 into a pulse sequence with constant amplitude and output filter 8.

Phaser modulated signals works as follows

The PDKD 2, operating in the Libau-Craig code, provides for the division of the circular frequency of the COO of the pulse generator 1 with the recalculation factor Q ,, / Square-shaped pulses are generated at its discharge outputs, and at the output with the circular frequency co. The decoder 3 converts the DPKD 2 output signals in the Liebau-Craig code into a decimal code.

Shaper 4 generally consists of a recalculation unit with an O / 2n conversion factor and a reverse trigger, at the outputs of which control signals for the reversing shift register 5 are formed so that initially (a single voltage level is formed at the first output of the driver A) reversing register 5 the shift is set to the operation mode on addition - the temporary position of the generated pulses is shifted to the right (Fig. 2a, b, c) - until the filling of the former 4, and then (a single voltage level is formed

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at the second output of the imaging device 4) - to subtract - the temporal position of the generated pulses is shifted to the left (Fig. 2d, e, f) - etc.

At the outputs of the two-bit triggers (for example, the n-th and (n + 1) -th bits) of the reversing shift register 5, the units (unit voltage level) are recorded by the bit inputs. Depending on this, in the decoder 3 the corresponding bits will be unlocked, through which the signals from the DPKD 2 output set the duration G, - (in this case, the minimum) of the generated pulses (Fig. 2a), which corresponds to the maximum modulation index of the phase-modulated signal at the driver output phase modulated signals. With the next decrease in the modulation index of the phase-modulated signal to the next stage, it is enough to write down the units at the outputs of the n-th and () -th triggers of the reverse shift register 5, etc.

When forming a phase-modulated signal in the frequency range with ±

t U with DPCD 2 and shaper 4 generally have a variable conversion factor, which is set when the initial state is set.

Transmitter 7 can generally consist of a control trigger and a key that commutes the reference voltage. The time-generated pulse signal, the pulse duration of which is given by stable pulses arriving at the input of the converter 7, from its output goes to the filter 8, at the output of which a phase-modulated signal is formed.

The temporal position of the generated pulses is varied according to the triangular law shown in FIG. 3, and at the output of the filter 8, harmonics corresponding to the harmonic law of phase modulation are extracted.

In the case of a fixed frequency, before starting work on the discharge inputs of the reverse shift register 5, to which the modulation index setting signals are applied, the unit voltage levels are set. Depending on the bits in the 5-shift reverse register, units are set, in the decoder

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3, the corresponding two bits will be unblocked, along which the passage of pulses from the PDCD 2 outputs is possible to form, in this case, the minimum pulse duration T; (Fig. 2a), corresponding to the maximum value of the phase modulation index at the output of converter 7. KDCD 2 is prepared to receive input pulses "Shaper 4 is in this state

The shift master 5 sets the shift mode to the right of the recorded two units. At the outputs of the generator 1 of the Converter 7 and the output filter 8 signals are missing.

The generation of phase-modulated signals starts from the moment the trigger signal is applied. In this case, the pulses from the output of the generator 1 are fed to the input of the PDKD 2. When a single bit coincides from the output of the PDKD 2 with the corresponding first unlocked bit in the decoder 3, a signal is generated at its output, which through the OR 6 element goes to the converter 7. At its output a rising edge of a positive pulse is formed. When the next single bit from the DPCD 2 output coincides again with the corresponding second unlocked bit in the decoder 3, a signal is generated which through the OR 6 element goes to turn off the converter 7. At its output, the trailing edge of the positive pulse is formed. At the moment of filling the PDDK 2, the formation of the period of the pulse sequence at the output of the converter 7 is completed. The signal from the output of the PDKD 2 in the reverse shift register 5 shifts two units to the right (in the decoder 3, the corresponding two most significant bits are unlocked), and a pulse arrives at the input of the former 4. When forming the next period of the pulse sequence at the output of the converter 7, the leading and trailing edges of the pulse being formed are shifted to the right (in Fig. 2b, the shift of the pulse center to the right is shown, which is equivalent for 5; that is, the pulse duration), etc. The discreteness of the change in the temporal position of the generated pulses is t; carried out with the frequency of the carrier signal.

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The shift of the temporal position of the generated pulses to the right continues until the filling of the former 4. When the imaging unit 4 is filled, the signals change at its output. In this case, in the reverse shift register 5, the operation mode is set to shift two units to the left. In the future, the phase-modulated signal generator works as described, except that the time position shift of the generated pulses at the output of the converter 7 is left (Fig. 2d, e) until filling agent 4, etc. The change in the temporal position of the generated pulses at the output of the transducer 7 is carried out with the frequency of the modulating signal according to a triangular law (Fig. 3).

Claims (1)

Invention Formula A phase-modulated waveform shaper comprising a pulse generator and a series-connected OR element, a converter of a sequence of pulses with variable amplitude into a sequence of pulses of constant amplitude and an output filter, the input of the pulse generator being the start signal, characterized in that, in order to reduce non-linear distortions of the output signal inverter control signal generator and reversible shift register connected in series, as well as a frequency divider with a variable division factor, the input of which is connected to the output of the pulse generator, and the output - to the control input of the reverse control signaling generator and to the control input of the reverse version of the shift register decoder , each of the bit inputs of the first group of inputs of which is connected to the corresponding bit output of a frequency divider with a variable division factor, each of the bit the inputs of the second group of inputs are with the corresponding bit output of the reverse shift register, and the bit outputs of the decoder are connected to the corresponding inputs of the OR element, while the bit inputs of the reverse register are shifted to the modulation index control signal. D five FIG. 2 ftiloi) fti mom ABOUT 7G12 ftsg.Z Editor E. Kopcha Compiled by G. Zakharchenko Tehred M. Khodanych 3Jr / 2 2X Proofreader V. But ha