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:
Jul. 15, 1997
Filed:
Jun. 06, 1995
John P De Loe, Jr, Decatur, GA (US);
He Feng Wang, Saitama, JP;
OKI telecom, Suwanee, GA (US);
Abstract
A circuit for connecting multiple signal paths within a multi-mode communication device includes a double balanced mixer circuit selectively functioning as a modulation switch during an unbalanced state. As applied to a transmit section of a CDMA/FM cellular telephone, a dual-function double balanced mixer circuit connects a CDMA IF signal path with an FM audio signal path. The double balanced mixer circuit includes a double balanced mixer connected through oscillator input to an external LC (inductor-capacitor) tank connected to both a PLL (phase lock loop) and an FM audio signal. One signal input of the double balanced mixer receives a CDMA low IF signal, while the other double balanced mixer signal input is connected to a microprocessor-controlled switch for selectively unbalancing the balanced mixer while in the FM mode of operation.