Browse Prior Art Database

Microsound FM Detector

IP.com Disclosure Number: IPCOM000074472D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Katyl, RH: AUTHOR

Abstract

This FM detector utilizes advantages of waveguiding techniques applicable to acoustic surface waves. Since the surface acoustic waves travel approximately 10/5/ times slower than electromagnetic waves, they permit a considerable amount of signal delay in a small package.

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Microsound FM Detector

This FM detector utilizes advantages of waveguiding techniques applicable to acoustic surface waves. Since the surface acoustic waves travel approximately 10/5/ times slower than electromagnetic waves, they permit a considerable amount of signal delay in a small package.

The FM detector shown employes waveguide type frequency discrimination to accomplish FM detection at, for example, 10.7 MHz. The detector is comprised essentially of configured thin-film wave-guide, input, output transducers 1a, 1b and acoustic absorbers 3a, 3b deposited on a piezoelectric type substrate. An RF signal is introduced by way of a RF input line onto the input surface wave transducer, 1a, where it is converted to surface wave energy. Hybrid junction 2a splits this incident signal equally into two waveguide branches A, B, in phase quadrature. If both of the split signals undergo equal phase shifts in paths A, B, then their sum will exit in port 1 and be absorbed in the acoustic absorber.

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The advantage of this approach is that it is compatible with integrated circuitry, and eliminates the requirement of a f.m. discriminator transformer. At a 10 MHz frequency, ceramic piezoelectric materials are usable and economical.

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