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:
Jun. 22, 1976
Filed:
Apr. 21, 1975
Siemens Aktiengesellschaft, Berlin & Munich, DT;
Abstract
A common emitter differential amplifier is arranged to receive an amplitude modulated high frequency signal and demodulate it. The common emitter differential amplifier has the emitters of two transistors connected together and these emitters are then connected through a constant current source to a reference potential. At least one of the collectors of the two transistors is connected through a collector resistor to a potential source. The collector of the other transistor is connected to the same potential source either directly or through a resistor associated with it. Negative feedback is provided through a serially connected rectifier and current amplifier. The output of the current amplifier is also connected through a low pass filter to an output terminal. The high frequency signal is fed to the base of one of the above transistors, while the base of the other transistor is connected to a reference voltage. When it is desired to have the differential amplifier provide push-pull rectification, two rectifiers are connected to the current amplifier in the feedback path from the collectors respectively, of the differential amplifier transistors. An improved circuit is shown for push-pull rectification in the negative feedback arm with symmetrical operation of the differential amplifier.