SU866696A1 - Device for shaping coherent frequency-modulated signals - Google Patents

Description

(54) DEVICE FOR THE FORMATION OF COHERENT FREQUENCY MODULATED SIGNALS

I

The invention relates to radio engineering and can be used to form coherent sequences of frequency modulated signals with both constant and variable values of the frequency change from pulse to pulse in systems using compression techniques.

A device for forming coherent frequency-1 modulated is known. signals, containing a sequentially connected reference oscillator, a frequency divider, a control voltage generator, a controlled generator and a fan-controlled auto-tuning system, starting the frequency of the controlled oscillator. a generator whose output is connected to the OTHER input of the control voltage generator, while another output of the frequency divider is connected to the input of the pulse generator, between the output of the reference oscillation generator and the other care of the phase-controlled system of the initial frequency of the controlled goner

To the torus, the frequency multiplier is switched on, - and the output of the limiter ij is connected to another input of the controlled oscillator.

However, the known device has a low speed and low accuracy of correction of phase deviations.

The purpose of the invention is to increase the speed of response and to improve the accuracy of the correction of phase deviations.

The goal is achieved by

10 that in a device containing a series-connected reference oscillator, a frequency divider, a control voltage generator, a control, a mobile oscillator, and a phase system

15 auto-tuning the initial frequency of the control & e. Motor generator, the output of which is connected to another input of the Control Voltage generator, while the other output of the frequency divider is connected to the input of the pulse generator, between the output of the generator of oscillations and another input of the system The basic auto-tuning of the initial frequency of the controlled generator includes a multiplier of the beach, and the output of the limiter, is connected to the other input of the controlled generator, between the output of the pulse generator and the input, the strobe is turned on. amplifying legal for trade, Tel, the other input of which is connected to another output of the frequency multiplier, the drawing shows a structural diagram of an electrical device. The device contains a control voltage generator 1, a controlled generator 2, a phase-controlled system for the initial frequency of the controlled generator, a gated amplifier 4, a limiter 5, an oscillator in onopHbix oscillation, a frequency multiplier 7, a frequency divider 8, and a driver 9 pulses,, Device works as follows. Managed by .-generator operates in continuous mode. At the beginning of the formation of the frequency-modulated: signal, the initial frequency of the dcr and phase: The voltage at the output of the controlled oscillator 2 is maintained by system 3 equal to the corresponding parameters of the reference voltage supplied to its input. The reference voltage is formed by a frequency multiplier 7 of the voltage of the generator 6 of the reference oscillations. As a result, the comparison of the reference signal and the output voltage of the controlled oscillator 2. supplied to. the other input of the system, the voltage of the error, which, from its output through the control voltage generator 1, is applied to the input of the controllable generator, has made its adjustment. Binding of the initial frequency and phase of the voltage generated by the controlled generator 2. to the reference one. Provides interperiod coherence of the generated signals. The frequency divider 8 from the voltage with the frequency FO of the reference oscillator 6 generates impedances often, as follows P and Pcp nf. arriving at generator 1 of control voltage and shaper 9 impulse from its second and first outputs, respectively ri and k - division factors), On the arrival of a starting pulse from frequency divider 8, generator 1 is started, forming a sawtooth voltage E (t.) the duration of the period f IM uiLC nU / UlVl. PG1L. Y - p and simultaneously opens the circuit for passing the error signal of system 3. Under the influence of the control voltage E (t), whose parameters are selected taking into account the modulation characteristics of the controlled generator 2, its frequency varies linearly) The correction of phase distortions is made through regular time intervals, between which the phase increment of the ideal-linear-frequency-modulated (chirp) signal with parameters D and f is a multiple of, for example, two, the sampling period in this case, as well as for a pulse biased The auto-tuning mode f AP) LMC is selected from the condition. The phase distortions in the device are corrected as follows, Сгро. .., amplifier 4 being built forms a coherent radioimpu sequence. , with a carrier frequency n, a duration of THG and a repetition period p. Moreover, each starting impulse arriving at the control voltage generator i coincides with the time interval with one of the radio pulses having a constant initial phase. The duration of the generated radio pulses is chosen less than the value of up-l. Radio pulses are output from the output of the test amplifier 4. Limiter 5. Executed, for example. on a traveling wave tube, which amplifies and aligns the amplitudes of its harmonic components in the frequency band from f c {. to sh. Cif. The generated high frequency signal is fed to the second input of the control generator 2,. As the second input of the control generator 2, a communication element with its oscillating system or one of the inputs can be used. . “The fireworld, connected to its output. The signal entered through the second input phase-out it, t, e, on the phase of the synchronization signal of the Gradioimpuza coming from the limiter I) and, accordingly, eliminating the phase shift due to deviations of the output voltage of the controlled generator from the desired law of variation caused by destabilizing factors, both internal and external. Phasing is carried out in woivieHTbi multiple phase shift in the distant LMP. shaking Not with the given parameters uf and f. This ensures intra-coherence of the generated L signals.

Since the oscillation frequency during the signal duration varies, the phasing at each individual moment is carried out by a certain harmonic component of the generator 2 of the phasing radio pulse, which prevents its frequency from being shifted due to the frequency pickup of the voltage source 5 of the sync source {) Oniza1Shv. The necessary time for phasing f, respectively, the time for correcting for phase distortions of the LM oscillation) is determined by the inertia of the controlled oscillator 2 itself and for limestone microwave devices lies within a few tens of nanoseconds.

The accuracy of the correction of phase distortions is proportional to the ratio of the magnitudes of the frequency detuning from the required law of variation of the frequency of the LMP signal and the synchronization band of the controlled oscillator 2, the magnitude of the synchronization band of the known oscillators reaches. hundred megahertz. .- By changing the division factor of the frequency divider 8 and parameters parameters, (it is possible to control the parameters of the signals generated sufficiently flexibly.

Thus, the invention allows to increase the speed of the device, with the exception of the inertial links of the impulse phase self-tuning phase, and the accuracy of correction of phase deviations in the generated M signal.

8666966

more than 2 times, and also to increase the stability of the correction system and to simplify the technical implementation in comparison with the known device, 5

Claims (1)

1. Cybbler, Method of shaping pulses with linear frequency modulation (Zaruba & a electronics, .1969, N9 11G.2e-3Z PROTOTIP). 6 five t- 7