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:
Nov. 30, 1993
Filed:
Jan. 24, 1991
Peter Harrison, Ascot, GB;
Technophone Limited, , GB;
Abstract
A transceiver for a cellular telephone, particularly a portable telephone, comprises a transmitter and a receiver coupled to a common antenna by an antenna duplex filter. The duplex filter comprises two passband filters connected respectively to the transmitter and the receiver. The receiver comprises a first amplifier. A notch filter tuned to the transmit frequency is connected to the output of the amplifier. The notch filter enables the filtering performance of the receive filter to be relaxed, and the location of the notch filter(s) at the output of amplifier means that the insertion loss is less critical. The requirement for lower filtering performance enables the duplex filter to be smaller and less costly.