SU743161A1 - Device for shaping linearly-frequency-modulated oscillations - Google Patents

Description

one

The invention relates to radio engineering and can be used as a device for generating signals with angular modulation in systems with an independent source of carrier wave.

A device for forming linear-frequency-modulated oscillations, comprising a serially connected binary counter and a first phase-shifting device, as well as a code 1 generator, is known ..

However, in the output signal spectrum of a known device there are parasitic components of a significant level arising due to the discrete nature of the phase change, and the decrease in the discrete value leading to a decrease in the level of the parasitic components is limited by the speed of the counting circuits and the time of the phase shifter.

The purpose of the invention is to reduce the level of spurious components in the spectrum of the output signal.

To do this, a second phase shifter, the first control inputs of which are connected to the outputs of the binary counter, are connected in series to the linear-frequency shaping modulated cobbles — a scientific research institute containing a serially generated binary counter and a first phase shifter and a code generator. There are 10 state voltages and a low-frequency switch, the outputs of which are connected to the second control inputs of the first and second phase shifters, high-frequency switch, whose inputs are connected to the outputs of the first and second phase shifters, and a trigger with a counting input connected between the output of the code generator and the combined control inputs of the low 20 frequency and high frequency switches, the control input of the binary counter and the third control inputs of the first and second faudal shift

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devices, while the signal input of the first phase-shifting device is combined with the signal input of the second phase-shifting device, the linear voltage generator start input with the trigger trigger inputs with the counting input, the code generator and the binary counter, and the alternating voltage generator input - with the reset input of the code generator, the phase-shifting device being designed as a series-connected, smooth phase shifter, to the control input of which the integrator is connected a discrete phase shifter, to the control inputs of which memory outputs are connected, the input of the smooth phase shifter is the signal input of the phase shifter, the first memory input is the first control input of the motor phase generator, the first control input is the integrator of the second phase shift control input. the combined control input of the integrator and the second input of the storage device are combined with the third control input of the phase-shifting device, and the output of the discrete phase shifter - the output of the phase-shifting device.

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

The device contains a linear-varying voltage generator (GLINE) 1, low-frequency switch 2, first and second phase shifters 3 and 4, a trigger with counting input 5, code generator 6, binary counter 7, high-frequency switch 8. Each phase shifter 3 and .4 contains a smooth phase shifter 9, a discrete phase shifter 1O, an integrator 11 and a storage device 12.

The device for forming linear-frequency-modulated oscillations operates as follows.

At the output of the code 6 generator, pulses appear at VTC time intervals when the conditions

itTTf cn-i): si eMitTf n: /: 4e,

pdeU - the required parameter of the law

frequency changes in Hz / s;

four

 g J- - quantization step in time, T equal to the clock period

frequency f-f. Phase shifters 3 and 4 have K-1 bits controlled by binary counter 7, and one bit set at the beginning and not having its state during the whole cycle of operation, as in the first phase shifter 3 the values phases equal to j - AT 26, and in the second phase-shifting device 4 the values of the phases are set equal to, CkЧ (), where 6 is an integer corresponding to

5 state of binary counter 7.

Thus, the lower bit in the storage device 12 of the first phase shifter 3 during one cycle will have the same value equal to O, and in the memory device 12 phase shifting device 4 equal to 1, which are set at the beginning of the cycle. High frequency switch 8 alternately connects to the output

5 devices first 3 or second 4 phase shifters.

Let at the moment of time at the output of the shaper code 6 by the force of the pulse and at the moment t (hH) at the output

0 was connected to the first phase-shifting device 3, that is, in the memory 12 of the first phase-shifting device 3 the number 6-1 was set, and in the memory 12 of the second

5 phase-shifting device 4 - number 6.

The pulse from the output of the shaper code 6 changes the state of the trigger 5, resulting in a low-frequency switch 2 and high-frequency switch 8

0 push the output of the second phase-shifting device 4.

In addition, the signal from trigger 5 blocks the recording in the storage device. 12 and reset the integrator 11 second

5 of the phase shifter 4 and vice versa allows writing to the memory 12 and resetting the integrator 11 of the first phase shifter 3. After the triggering of the trigger 0 5 is completed, the contents of the binary counter 7 are increased by 1, becomes equal to sil AND transferred to the memory 12 of the first phase shifter 3 .

Claims (1)

1. US Patent 3,792,378, Cl. H 03 H 19/00 (331-178), published. 1974 (prototype).