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:
Sep. 19, 1989
Filed:
Feb. 03, 1988
Robert N Sato, Palos Verdes, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An integrating transimpedance amplifier 10 comprises a differential amplifier constructed of GaAs, MESFET, HEMT, SDHT or MODFET transistors has an input coupled to the output of a radiation detector 12 and an output expressive of the detector signal integrated over a predetermined interval of time. The amplifier has a transistor Q0 coupled to the input for coupling the input periodically to a predetermined voltage potential and a transistor Q.sub.9 coupled to the output of the amplifier for simultaneously periodically coupling the output to a predetermined voltage reference, thereby initializing the amplifier at the beginning of an integration period. A buffer transistor Q.sub.4 couples the output of the amplifier to a GaAs MISFET switch Q.sub.8 which is periodically activated to couple the buffered amplifier output to a storage capacitor Csmp. The buffer transistor also couples the output of the amplifier to a feedback capacitor Cf which is connected between the output of the buffer amplifier and the input of the amplifier for minimizing an effect associated with the radiation detector parasitic capacitance. The magnitude of the buffered amplifier output is stored on the capacitor at the beginning and end of the integration period. The sample signal is read out by a multiplexer twice during the integration period, the difference between the initial and final value of the buffer amplifier output being indicative of the radiation impinging on the detector minus one or more noise components.