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:
May. 17, 1994
Filed:
Oct. 22, 1992
Hironori Sakamoto, Mitaka, JP;
Satoru Ohara, Mitaka, JP;
Toshio Nojima, Yokosuka, JP;
Shoichi Narahashi, Yokosuka, JP;
Makoto Maeta, Yokosuka, JP;
Japan Radio Co., Ltd., Tokyo, JP;
Nippon Telegraph & Telephone Corporation, Tokyo, JP;
NTT Mobile Communication Network Inc., Tokyo, JP;
Abstract
In a receiver comprising a receiver filter (12) with a frequency attenuation band and a pilot oscillator (25) for generating a pilot oscillation signal with a pilot frequency in the frequency attenuation band, a coupler (26) couples the pilot oscillation signal and a filtered receiver signal of the receiver filter to form a coupled signal. A low noise amplifier (13) amplifies the coupled signal into an amplified signal which comprises an amplified receiver signal component derived from the filtered receiver signal and an amplified pilot oscillation signal component derived from the pilot oscillation signal. A branching filter (27) branches the amplified signal into the amplified receiver signal component and the amplified pilot oscillation signal. A pilot signal component detector unit (28) detects the amplified pilot oscillation signal component to produce a direct pilot signal. A failure monitoring unit (29) monitors the direct pilot signal to produce a fault signal when the direct pilot signal is found faulty.