SU640421A1 - Acoustic delay line - Google Patents

Description

one

The invention relates to the field of radio electronics and can be used in systems for generating and optimal processing of radio and sonar signals.

The known acoustic line of the gate 1 comprises a tubular waveguide having a central portion and a double end section on which electromechanical transducers are mounted. However, this delay line does not provide a sufficiently wide time and frequency range.

The closest solution to the technical essence and the achieved result is an acoustic delay line comprising an elastic tubular waveguide with a varying outer diameter along its length, two end sections and an exciter and receiver electromechanical transducers mounted on the end sections 2.

However, this delay line also has a frequency and time range.

The purpose of the present invention is to eliminate the drawbacks and reduce the level of flashing signals at the input. This is achieved due to the fact that the waveguide is made with an internal diameter varying along its length, a. also due to the fact that vol2

The bridge has an inner and outer diameter decreasing to its ends and has a constant wall thickness.

The figure shows an acoustic delay line.

The line contains a tubular waveguide 1, radiating 2 and receiving 3 electromechanical transducers for excitation and reception of a zero asymmetric mode, installed on the end sections of the waveguide, plugs 4 of absorbing material, such as rubber, used to eliminate reflections of the surge waves from the ends of the waveguide 1.

The delay line in processing, for example, a signal with linear frequency modulation, works as follows.

Voltage of chirp signal with amplitude L, DG duration and frequency band D /

using the electromechanical transducer 2 to convert into zero axisymmetric mode of oscillation of the walls of waveguide 1. Since the slope of the time-frequency characteristic of the delay line is chosen equal in magnitude and opposite to the sign of the slope of the time-frequency characteristic of the LCL1 signal, when the oscillations propagate in waveguide 1 the phase difference the frequency components of the LCL1 signal is reduced and

at the point of receiver transducer 3 becomes zero. Elastic vibrations are received at the other end of waveguide 1 by a receiving electromechanical transducer 3, with which they are transformed into an electrical voltage of a compressed signal, whose duration is 0.637 amplitude equal to 1 / LD and the amplitude, without taking into account distribution losses in the delay line, is equal to.

Claims (3)

1. Acoustic delay line, comprising an elastic tubular waveguide with a varying outer diameter along its length, two end sections and an excitation and receiving electromechanical transducers installed at the end sections, characterized in that, in order to expand the frequency and time range, The waveguide is made with an internal diameter varying along its length. 2. Acoustic delay line according to claim 1, characterized in that, in order to reduce the level of interfering signals on the SS output, the guide is made with reducing its ends to the ends of the linear and outer diameters. 3. Acoustic delay according to claims. 1 and 2, characterized in that the waveguide is made with a constant wall thickness. Sources of information taken into account in the examination 1. US patent number 3605043, cl. 333--30, inub. 14.09.71. 2. USSR author's certificate number 537581, cl. N OZN 9/30, 08/06/76. .- I Jj