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:
Jan. 17, 1989
Filed:
Aug. 20, 1987
Syuichi Mitsutsuka, Tokyo, JP;
Clarion Co., Ltd., Tokyo, JP;
Abstract
An optimum bias circuit for a convolver according to this invention searches automatically a bias voltage, which makes the convolution efficiency of a surface acoustic wave convolver highest and applies it to the gate electrode of the convolver. It consists of an impedance bridge consisting of a plurality of fixed impedances, a reference impedance, and an impedance constituted by the gate electrode of the convolver, a signal source for the impedance bridge, an amplifier amplifying the output of the bridge, a differential amplifier amplifying the signal for the bridge, a phase detector, a DC amplifier and an integrating circuit, and is so constructed that the phase detector detects the phase of the output of the bridge (amplified signal) by using the output of the differential amplifier as a reference signal; the DC amplifier amplifies the output after the phase detection; the integrator integrates the output of the DC amplifier; and the output of the integrator is applied to the gate electrode of the convolver.