Transmitter/receiver having an antenna failure detection system

• US 6,253,067 B1
• Filed: 06/25/1998
• Issued: 06/26/2001
• Est. Priority Date: 06/27/1997
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tsuji, Kazushi
• Primary Examiner(s): Cumming, William
• Assistant Examiner(s): CHOW, CHARLES CHIANG
• Application Number:
  US09/104,220
• Time in Patent Office: 1,097 Days
• Field of Search: 455/67.4, 455/562, 455/115, 455/97, 455/226.1, 455/423, 455/425, 375/216, 375/219
• US Class Current: 455/115.2
• CPC Class Codes: H04B 17/19 Self-testing arrangements
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements

Abstract

A transmitter/receiver in a base station comprises an antenna failure detection system including a receiving antenna for receiving a first signal from own station through a transmitting antenna and a second signal from another station, a channel filter for separating the first signal and the second signal, a detector for detecting the second signal, and a comparator for comparing the level of the detected signal, which is proportional to the coupling factor between the transmitting antenna and the receiving antenna, against a threshold to output an antenna failure signal based on the result of the comparison. The antenna failure detection system operates in a normal operation mode of the transmitter/receiver without reducing the number of service channels.

Claims

1. A transmitter/receiver comprising a transmitter, a transmitting antenna for transmitting a first signal supplied from said transmitter, a receiving antenna for receiving said first signal and a second signal from a station to deliver an antenna signal, a separator for receiving said antenna signal to separate said first signal and second signal, a receiver for receiving said second signal from said separator, a detector for detecting said first signal to output a detected signal which is proportional to a coupling factor between said transmitting antenna and said receiving antenna, and a comparator for comparing said detected signal against a reference to output an antenna failed signal based an the result of the comparison.

2. A transmitter/receiver as defined in claim 1, wherein said separator comprises a pair of band-pass filters including a first filer passing a band of said fast signal and a second filter passing a band of said second signal.

3. A transmitter/receiver as defined in claim 1 further comprising a radio-frequency amplifier connected between said separator and said detector.

4. A transmitter/receiver as defined in claim 1 further comprising an antenna sharer between said transmitting antenna and said transmitter, wherein said transmitting antenna is implemented as a frequency antenna shared with another receiving antenna.