The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 1977
Filed:
Jan. 26, 1976
Kokichi Morii, Chigasaki, JA;
Ken-Ichi Urayama, Kamakura, JA;
Sony Corporation, Tokyo, JA;
Abstract
A filter circuit includes an acoustic surface-wave filter device having an input transducer comprised of a set of interleaved electrodes disposed on a first portion of a body of piezo-electric material adapted to propagate acoustic surface waves for producing an acoustic surface-wave signal in response to an input signal applied to the input transducer, and an output transducer comprised of a set of similar interleaved electrodes disposed on a second portion of the piezo-electric body spaced a selected distance from the first portion for receiving the acoustic surface-wave signals so as to produce a corresponding output signal having a selected frequency response. The frequency response (e.g., bandwidth) of the acoustic surface-wave filter device is controlled by selectively changing the number of conductor elements constituting the interleaved electrodes of the input and output transducers. An amplifier drives the acoustic surface-wave filter device, the gain and output impedance of the amplifier being changed as the frequency response of the acoustic surface-wave filter device changes, so as to compensate for corresponding changes in the insertion loss and input impedance of the filter device.