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:
Feb. 27, 1979
Filed:
Jan. 03, 1978
Christopher R Huntley, Burnaby, CA;
GTE Automatic Electric Laboratories, Inc., Northlake, IL (US);
Abstract
A double sideband suppressed carrier (DSBSC) modulator for operation from unbalanced carrier frequency and modulation frequency sources has the input terminals of first and second constant current amplifiers connected to receive the modulation frequency output signal from the unbalanced source. The first and second constant current amplifiers provide in-phase and out-of-phase modulation frequency signals at respective high impedance output terminals for connection to a modulator. The modulator comprises a quad, i.e., four transistors connected to provide a pair of differential amplifiers. Transistors 1 and 2 comprising the first of the pair and transistors 3 and 4 comprising the second of the differential pair. The emitters of each differential amplifier are tied together. The emitter junction of the first differential amplifier is connected to the high impedance output of the first constant current amplifier, and the emitter junction of the second differential amplifier is connected to the high impedance output of the second constant current amplifier. The base of transistors 2 and 3 are connected together and then connected to one terminal of the carrier frequency source. The bases of transistors 1 and 4 are connected together and then connected to the other terminal of the carrier frequency source. The collectors of transistors 1 and 3 are tied together and the collectors of transistors 2 and 4 are tied together to provide the modulated signal output paths.