SU642853A1 - Generator of radio pulses with frequency-modulated carrier frequency - Google Patents

Description

The invention relates to radio engineering and can be used in devices for generating frequency modulated radio pulses.

A known generator of radio pulses with a frequency-modulated carrier frequency, comprising a series-connected reference generator, a delay line, a frequency multiplier and a pulse amplifier, a series-connected pulse generator and an integrator, as well as a synchronizer, one output of which is connected to another input of a pulse amplifier and the other output to the input of the pulse generator 1.

However, the known generator of radio pulses with a frequency-modulated carrier frequency does not allow a significant increase in the carrier frequency deviation and duration. linear frequency modulated (chirp) radio pulse due to the fact that it is unipolar phase modulation.

The aim of the invention is to increase the deviation of the carrier frequency of the radio pulse.

To do this, in a radio pulse generator with a frequency-modulated carrier frequency, containing a series-connected reference generator, a delay line, a frequency multiplier and a pulse amplifier, a series-connected pulse generator and an integrator, as well as a synchronizer, one output of which is connected to another input of the NMR amplifier, and another output is connected to the input of the pulse generator, between the output of the pulse generator and the control input of the delay line there are additionally introduced a series-connected inverter and an adder whose other input is connected to the integrator output.

FIG. 1 shows the structural electrical circuit of the generator; in fig. 2 - voltage plots at various points of the generator; on fng. 3 - graphs of phase and frequency changes in the generator.

The radio pulse generator with a frequency-modulated carrier frequency contains a series of connected reference generator 1, delay line 2, frequency multiplier 3 and pulse amplifier 4, series-connected pulse generator 5 and integrator 6, as well as a synchronizer 7, one output of which is connected to

another input of the pulse amplifier 4, and another output to the input of the pulse generator 5, the inverter 8 and the adder 9, the other input of which is connected to the output of the integrator 6, are inserted between the output of the pulse generator 5 and the control input of the delay line 2.

The generator of radio pulses with a frequency-modulated carrier frequency works as follows.

Harmonic oscillations from the reference oscillator 1, for example, a quartz oscillator, arrive at a controllable delay line 2, made in the form of a series of inductors, in taps between which and the ground are connected electronic tunable shunt diodes. These capacitive diodes through the integrating resistor receives a control pulse from the output of the adder 9. The formation of the control voltage is as follows. The direct coal pulse produced by the pulse generator 5 is fed to the integrator 6 and the inverter 8 (see Fig. 2 a). Integration of rectangular pulses creates linearly varying voltage in the form of pulses of one, in this case, positive polarity (see Fig. 26). At the output of inverter 8, a rectangular pulse is obtained, the polarity of which is opposite, and the amplitude is equal to half the amplitude of the linear-varying pulse (see Fig. 2c) .. At the output of the adder 9, a bipolar linear-varying pulse is produced, in which At the beginning of the pulse, the pulse has not a zero value, but the maximum value and, changing linearly, passes through the center of the pulse zero, reaching the amplitude value of the opposite polarity at the end of the pulse (see; fig. 2 g). Under the influence of such a control pulse, the voltage on the shunt diodes is due to the integration of the measurement. according to the law of a two-sided parabola (see Fig. 2e). This, in turn, leads to the fact that the phase of the signal at the output of the delay line 2 changes during a pulse also according to the law of a two-way parabola (see Fig. Pro), providing a two-way, symmetrical frequency sweep (see Fig. 36). Further, the frequency-modulated oscillation is supplied to frequency multiplier 3, where the carrier frequency and frequency deviation increase by an integer number of times.

Then the pulse amplifier 4 provides gating radio pulse and power amplification.

From the output of the pulse amplifier 4, the radio pulses enter the antenna and are emitted. The pulse amplifier 4 and the pulse generator 5 are started from the synchronizer 7. The proposed radio pulse generator makes it possible to obtain a bipolar phase change and to increase by four times the conversion efficiency of the range of the phase change within the linear frequency change. This is explained by the fact that in the proposed generator of radio pulses the range of phase restructuring is used

twice during the time of the chirp radio pulse, a linear frequency change is formed both with decreasing phase during the first half of the pulse and increasing phase with the second half of the pulse. When the phase is shorter, the frequency is less than the initial one and linearly increases from the lowest to the initial one; when the phase is increased, the frequency is higher than the initial one and linearly increases from the initial to the largest one (see Fig. 3).

Compared with the known generator of radio pulses with a frequency-modulated carrier frequency, the proposed generator allows the frequency deviation and the duration of the chirp pulse to be doubled.

Claims (1)

Invention Formula A radio frequency generator with a frequency-modulated carrier frequency, containing a series-connected reference generator, a delay line, a frequency multiplier and a pulse amplifier, a series-connected pulse generator and an integrator, as well as a synchronizer, one output of which is connected to another input of the pulse amplifier and the other output to the input of the generator impulses, characterized in that, in order to increase  carrier deviation The frequency of the radio pulse between the output of the pulse generator and the control input of the delay line is connected in series with the inverter and the adder, the other input of which is connected to the integrator output. 5Q Sources of information taken into account during the examination I. US Patent No. 3382497. Cl. 343-17.2, 1968. Her