SU1392628A1 - Phase telegraphy signal modulator - Google Patents

Abstract

The invention relates to electronics. The purpose of the invention is to increase the modulation speed, accuracy and stability of the phase sampling. The device contains a reference oscillator I, phase detector 2, adjustable oscillator 7. Amplitude comparator 3, polarity switch 4, low-pass filter 5, adder 6, delay block 8, EL-EXCLUSIVE OR 9, block 10 for detecting and fixing the phase mismatch are introduced consisting of filters 11 and 17, voltage source 12, amplitude comparator 13, rms 14 counting pulses, reversible counter 15, DAC 16. The device operates in two modes: search mode and synchronous mode. The state of the phase mismatch between the oscillations of G-1 and 7 and, consequently, the control of the phase-keying of the output signal (output 19) is monitored by the video signal supplied from the comparator 3 to the control output 20. The inertia of the filters 5 and 11 that is, during the transfer of the phase of Mr. 7 to 180 voltages, their outputs practically did not change. This allows the device to maintain the synchronous mode of operation of Mr. 7 in the device and significantly reduce the time of transient processes during the manipulation of its phase by 180. 1 hp f-ly, 1 ill. with (L

Description

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The invention relates to radio electronics and can be used in radio location and digital information transmission systems.

The purpose of the invention is to increase the modulation speed, accuracy and stability of the phase sampling.

The drawing shows a structural electrical circuit of a pushed modulator.

The phase telegraphy signal modulator contains a reference generator 1, a phase detector 2, an amplitude comparator 3, a polarity switch A, a low-pass filter 5, an adder 6, an adjustable oscillator 7, a delay block 8, an element EXCLUSIVE OR 9, a phase search and fixation unit 10 misalignment, consisting of the first low-pass filter 11, the source 12 of the reference voltage, the amplitude comparator 13, the generator 14 of the counting pulses, the reversible counter 15, the digital-analog converter 16 and the second low-pass filter 17.

The modulator operates as follows.

At the initial moment of time (when the device is turned on), a beat voltage occurs at the output of the phase detector 2, due to the mismatch of the oscillation frequencies of the reference oscillator 1 and the adjustable oscillator 7, the amplitude comparator 3 together with the polarity switch A corrects the beat voltage, The signal level from the output of the filter 1I is less than the voltage from the output of the source 12, as a result of which the reversible counter 15 is turned on in one direction (search mode), a repeated linearity is formed at the output of block 10 increasing voltage koto Roe through the adder 6 modulates the frequency being adjusted frequency voltage generator 7. zheny beat output from the phase detector 2 thus varies linearly.

As the frequencies of oscillations approach the outputs of the reference I and the 7 beating generators being adjusted, the beating generators stop, the output voltage of the phase detector 2 and, correspondingly, of the polarity switch A occurs. At the moment when this voltage is exceeded, over a threshold urine, given by a source

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12, the unidirectional counting of the reversible counter 15 is stopped, the search mode is terminated, and the modulator switches to the synchronous operation mode.

A characteristic feature of this mode of operation in the proposed device is to fix the phase mismatch between the oscillations of the reference generator 1 and the adjustable generator 7 at the level specified by the reference voltage from the source output 12. After capturing the synchronous mode of operation, the modulator output oscillator tunable generator 7.

A modulating signal is supplied to modulator control input 18, which is a sequence of logic levels of ones and zeros. The EXCLUSIVE OR 9 element produces a zero voltage at its output if the logical signals at its inputs coincide or a fixed value voltage otherwise. In the stationary (equilibrium) state, the logical signals at the input of the EXCLUSIVE OR 9 element coincide, and at the output its voltage is zero.

When the logical level at the input 18 of the modulator changes, a voltage jump appears at the output of the EXCLUSIVE OR 9 element, which drastically shifts the frequency of the adjustable oscillator 7. At the same time, the phase difference between the oscillations of this generator and the reference generator 1 begins to change rapidly during time, which leads to a change in voltage at the output of the phase detector 2 in accordance with its discriminatory characteristic (for example, according to a sinusoidal law). At the moment of transition of the output voltage of the phase detector 2 through zero, the amplitude comparator 3 is triggered, the state of its logic output changes abruptly. This signal, at a time interval determined by the delay of block 8, appears at the second input of the EXCLUSIVE OR 9 element, returning its output to the initial state, i.e. to zero voltage. The oscillation frequency of the adjustable oscillator 7 also abruptly returns to a value equal to the oscillation frequency of the reference oscillator 1. The signal delay in block 8 is chosen so that the frequency of the adjustable oscillator 7 returns to its initial state at a time corresponding to the equal voltage at the output of the switch 4 polarity and reference voltage from the output of the source 12. After the termination of the described processes, the modulator is again in an equilibrium state that differs from the previous shift ogicheskogo state amplitude output signal of the comparator 3, and hence, the phase offset mismatch between the oscillation of the reference I and predstraivaemogo 7 generators 180 °.

Thus, each change in the logic level of the signal at the input 18 of the modulator corresponds to a change in the phase of the adjustable oscillator by 180 °.

The phase mismatch between oscillations of the reference 1 and adjustable 7 generators is monitored and, therefore, the phase manipulation of the output signal of the modulator output 19 can be monitored by the video signal supplied from the output of the amplitude comparator 3 to the control output 20 of the device.

The inertia of the filters 5 and I1 are chosen so that during the phase transfer time of the adjustable oscillator 7 by 180 ° the voltage at their outputs does not practically change. This allows the device to maintain a synchronous mode of operation of the adjustable oscillator 7 and, consequently, to reduce the time of transient processes during the manipulation of its phase by 180 °.

Claims (2)

1. Modulator of phase telegraphy signals, sequence contents VNSHSHI Order 1890/56 but connected a tunable oscillator, the output of which is the first output of a phase telegraphy signal modulator and a phase detector, the second input of which is connected to the output of a reference oscillator, characterized in that, in order to increase the modulation speed, Q and sampling stability phases, serially connected amplitude comparator, polarity switch, phase mismatch search and fixing unit 5 and an adder, as well as a low-pass filter, a delay unit and an EXCLUSIVE OR element, the output of the phase detector connected to the first input of the amplitude comparator and the second input of the polarity switch, the output of which through the low-pass filter is connected to the second input of the adder, the third input of which connected to the output element EXCLUSIVE OR, 5 and the output to the input of the adjustable generator, the second input of the amplitude comparator is connected to an equal potential potential, and the output is the second input of the modulator of the signals Q phase telegraphy and through a delay block is connected to the first input of the EXCLUSIVE OR element, the second input of which is the input of the phase telegraphy signal modulator. 2. The modulator according to claim 12, or aphidi Di and so that the block for searching and fixing the phase mismatch contains the first low-pass filter, the input of which is the input “Phase mismatch searching and fixing unit, amplitude comparator, reference voltage source, counting pulse generator, as well as a series-connected reversing counter, digital-to-analog converter and a second low-pass filter whose output is the output of the phase mismatch searching and fixing unit, the inputs the amplitude comparator is connected to the outputs of the first low-pass filter and the source of the reference voltage, respectively; the control input of the reversible counter is connected to the output m amplitude comparator and its counter input connected to the generator output countable pulses. Circulation 660 Subscription five five