SU1720143A1 - Variable frequency signal synthesizer - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to provide a change in the frequency of the output signal according to the law of exponential function. The variable frequency signal synthesizer contains the initial frequency register 1, the accumulating adder (NS) 2, the shift register 3, the generator of 4 sequences of shifting pulses, the generator of 5 clock pulses. The code at the output of NS 2 is determined by the exponential function of discrete points in time. Generator 4 performs codeword shifts in shift register 3 by i bits in each calculation cycle. The goal is achieved by summing the obtained number with the contents of HC 2 achieved in the last count. 1 il. (L C vj ke O 00

Description

The invention relates to radio engineering and can be used in sonar, in particular when implementing the time delay spectrometry method.

The aim of the invention is to provide a change in the frequency of the output signal according to the law of exponential function.

The drawing shows a structural electrical circuit of a signal synthesizer with varying frequency.

The variable frequency signal synthesizer contains the initial frequency register 1, the accumulating adder (NS) 2, the shift register 3, the generator 4 of the sequence of shifting pulses, the generator of 5 clock pulses (GTI).

The variable frequency signal synthesizer operates as follows.

At the beginning of the formation of the signal, the initial frequency code from register 1 output is recorded in NS 2, the shift register 3 is zero and the initial frequency code Ki appears at the first clock pulse from the output of the GTI 5 shift to the right by 1 position (I is the number originally entered in the register of the number of shifts). On the next clock pulse in NS 2, the code Ki is added with the code KI X 2 shifted. The result of the addition of K2 Ki (re-entered in the 3 shift register.

The content of the accumulating adder at the ith clock count is K, Ki (I-2) - Ki-2 (H2) 2 ... Ki (1 + 2) M.

The code at the output of HC2 is determined by the exponential function of discrete points in time D. Each value of the output code HC2 can be assigned an instantaneous value of the sinusoidal envelope using the converter

phase code to amplitude code and a digital-to-analog converter (not shown).

If the phase of the signal at discrete points in time takes on the values Ki (1 + °) and, the instantaneous discrete value

+2

Frequencies are defined as the first difference of the lattice function D - Kfl-1 () 1. that is, the frequency also varies according to the law of exponential function.

Generator 4 performs codeword shifts in shift register 3 by I bits in each calculation cycle.

Each of the pulsed signals at the output bits of the NS 2 is also frequency modulated according to the law of exponential function and can be used as an output if the formation of a sinusoidal signal is not required. Delivered

The goal is achieved by deducing in each step the result of the summation into the shift register 3, with a subsequent shift by the number of positions recorded in generator 4, and by summing the number obtained with the contents of the NS 2 achieved in the last reading.

Claims (1)

Claims of a variable frequency signal synthesizer containing serially connected clock generator and accumulating adder, to the first code input of which the output of the initial frequency register is connected. shift pulse generator and shift register whose code output is connected to the second code input of the accumulating sum Ator, the code output of which is connected to the code input of the shift register.