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:
Jan. 04, 1994
Filed:
Oct. 11, 1991
Seijiro Ishizuka, Tokyo, JP;
Kazuto Kitakubo, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A antenna switching apparatus for a dual-mode transceiver which includes a transmission and reception antenna, a transmitting circuit, a receiving circuit, and a separating filter of large insertion loss is connected to the transmission and reception antenna, the transmitting circuit, and the receiving circuit for separating a transmission high frequency signal and a reception high frequency signal having different carrier frequencies, in which transmission and reception in the digital mode of the transmission and reception switching system and the transmission and reception in the analog mode of the simultaneous transmission and reception system is possible further includes an analog-to-digital change-over switch which changes-over mutual connections among the transmission and reception antenna, the transmitting circuit, the receiving circuit and the separating filter in response to the analog or digital mode, a blocking filter of low insertion loss for blocking a high frequency band of spurious signals caused by the switching of a transmission and reception change-over switch which changes-over the transmission and reception in the digital mode and a bandpass filter of low insertion loss for passing therethrough the reception high frequency signal in the digital mode, so that power consumption in the digital mode is reduced considerably.