RU1795538C - Delay line on acoustic surface waves - Google Patents

Abstract

The invention relates to acoustoelectronics and can be used to delay signals. The purpose of the invention is to increase the delay time. The delay line contains a sound pipe 1, on the surface of which there are four gratings 4,5,6 and 7 of inclined reflective elements, input 8 and output 9 surfactant converters. The gratings 4 and 5 are located in the first acoustic channel 2. Both transducers 8 and 9 are located between them. The gratings 6 and 7 are located in the second acoustic channel 3, parallel to the first. The electrodes of the transducer 9 and the inclined reflective elements of the grating 5 are divided in length into two parts, displaced one relative to the other along the acoustic channel 2 by the spatial pitch L and the width d of the reflective element, respectively. 1 ill.

Description

The invention relates to the field of acoustoelectronics and can be used to delay signals.

A known delay line (LH) on surface acoustic waves (SAWs) comprising a sound duct. on the surface of which there are two lattices of inclined reflective elements placed in two parallel acoustic channels, as well as input and output converters of surfactants.

This design has a short delay time determined by the double travel time of the acoustic wave between the transducer and any of the gratings.

Among the known technical solutions, the closest in design to the proposed one is a delay line on surface acoustic waves, containing a sound duct, on the surface of which there are four gratings of inclined reflective elements placed in pairs in two parallel acoustic channels, an input SAW transducer located between the gratings of the first pair , and a SAW output converter located between the gratings of the second pair.

The disadvantage of this design is the short delay time.

An object of the invention is to increase the delay time.

This goal is achieved by the fact that in a known LW on a SAW, the SAW output transducer is placed between the gratings of the first pair, while the electrodes of one of the converters and the inclined reflective elements of one of the gratings of the first pair are divided in length into two parts, offset from one another along the acoustic channel, by the size of the spatial step and the width of the reflective element, respectively.

The invention is illustrated in Fig. 1, which shows the construction of the proposed SAW delay line.

The delay line on the surfactant contains a sound pipe 1 (Fig, 1), on the surface of which in two parallel acoustic channels

2 and 3 there are four gratings 4,5,6 and 7 inclined reflective elements. The first pair of gratings 4 and. B is located in the first 2 acoustic channel. Between these gratings 4 and 5 there are input 8. and output 9 surfactant converters.

3 acoustic channels. The electrodes of one of the transducers (in this case 9) are divided along the length into two parts 10 and 11,

0

displaced relative to each other along the acoustic channel 2 by the spatial step L The inclined reflective elements of one of the gratings of the first pair (in this case 5) are also divided in length into two parts 12 and 13, displaced relative to each other along the acoustic channel 2 by the width d of the reflective element .

. The proposed LZ works as follows ..

An electrical signal is converted to an input converter 8

them into the acoustic wave. Hit on the inclined reflective elements of the lattice 5, the acoustic wave is reflected at an angle of 90 ° from its mutually displaced parts 12 and 13 in antiphase and does not enter the reflective elements of the lattice 7.

 Acoustic wave coming in. reflective elements of the grating 4 are reflected from them into the second acoustic channel

h. After double reflection from gratings b and 7, the acoustic wave enters again into the first acoustic channel to grating 5. From the mutually displaced parts 12 and 13 of the reflective elements of this grating 5, two antiphase waves AI and Aa go to the output transducer 9, two parts 10 and 11 of the electrodes which have a half-wave phase shift. As a result of this, an output occurs on the converter 9

electrical signal. Antiphase waves AI and A2 will not be received by input converter 8.

All gratings of 4,5,6 and 7 reflective elements or part of them can be dispersive.

In the proposed design, the functional input and output converters of surfactants: can be interchanged. Namely, use converter 9 as input. In this case, the parts used. 10 and. 11 electrodes of this transducer are two antiphase, acoustic waves are mutually compensated on the reflective elements of the grating 4. In

at the same time, these two antiphase waves arrive at the two parts 12 and 13 of the reflective elements of the grating 5 and, having acquired an additional half-wave phase shift, are in phase reradiated into the second

acoustic channel 3. After successive reflection from the reflective elements of the gratings 7,6 and 4, the acoustic wave enters the transducer 8, which in this case plays the role of the output. This inphase waveform will not be received by transducer 9 due to mutual half-wave displacement of parts 10 and 11 of the electrodes of this transducer.

The proposed LZ has twice as much delay time as the prototype and the analogue.

Claims (1)

The claims The delay line on surface acoustic waves (SAW), containing a sound conductor, on the surface of which there are four gratings of reflective elements, is placed in pairs in two parallel acoustic channels, the input SAW transducer located between the gratings of the inclined reflective elements of the first pair, and the output SAW transducer, about l the fact that, in order to increase the delay time, the SAW output transducer is placed between the gratings of the inclined reflective elements of the first pair, while the electrodes of one of the converters and the inclined reflective elements of one of the gratings of the first pair are made in the form of two parts separated along the length, offset from one another along the acoustic channel by the value of the spatial step and the width of the traction element, respectively.