Telecommunications – Receiver or analog modulated signal frequency converter – Local control of receiver operation
Reexamination Certificate
2011-07-19
2011-07-19
Le, Lana N (Department: 2614)
Telecommunications
Receiver or analog modulated signal frequency converter
Local control of receiver operation
C455S265000, C455S307000
Reexamination Certificate
active
07983644
ABSTRACT:
An apparatus and method for local oscillator calibration compensates for filter passband variation in a mixer circuit, such as a receiver circuit. The receiver includes at least a mixer circuit and a filter coupled to the output of the mixer. During operation, the mixer mixes an RF input signal with a first local oscillator (LO) signal to frequency translate a selected channel in the RF input signal into the passband of the filter. During a calibration mode, the RF input signal is disabled, and the first LO signal is injected into the filter input by leaking the first LO signal through the mixer circuit. The frequency of the LO signal is then swept over a frequency bandwidth that is sufficiently wide so that the actual passband is detected by measuring the signal amplitude at the output of the bandpass filter, thereby determining any variation in the passband of the filter from the expected passband. Once the actual passband is determined, then the frequency of the first local oscillator signal is adjusted or tuned to compensate for any frequency shift of the actual passband compared to the expected passband. Therefore, the selected channel is up-converted into the center of the actual passband of the bandpass filter and will not fall outside the passband. This enables the passband of the bandpass filter to be narrowed, as compared with conventional receivers that do not utilize this calibration procedure. For example, the bandpass filter can be narrowed to one or two channels wide.
REFERENCES:
patent: 3641515 (1972-02-01), Sues
patent: 4006420 (1977-02-01), Schittko
patent: 4031469 (1977-06-01), Johnson
patent: 4149122 (1979-04-01), Parato
patent: 4340975 (1982-07-01), Onishi et al.
patent: 4368468 (1983-01-01), Lisle et al.
patent: 4696055 (1987-09-01), Marshall
patent: 4858159 (1989-08-01), Wheelwright et al.
patent: 5179725 (1993-01-01), Camp et al.
patent: 5200826 (1993-04-01), Seong
patent: 5329319 (1994-07-01), Sgrignoli
patent: 5337014 (1994-08-01), Najle et al.
patent: 5390348 (1995-02-01), Magin et al.
patent: 5408196 (1995-04-01), Senpel et al.
patent: 5584068 (1996-12-01), Nohindra
patent: 5692279 (1997-12-01), Mang et al.
patent: 5737035 (1998-04-01), Rotzoll
patent: 5822687 (1998-10-01), Bickley et al.
patent: 5847612 (1998-12-01), Birleson
patent: 5930696 (1999-07-01), Tzuang et al.
patent: 5950119 (1999-09-01), McGeehan et al.
patent: 6009317 (1999-12-01), Wynn
patent: 6011962 (2000-01-01), Lindenmeier et al.
patent: 6028647 (2000-02-01), Fukai et al.
patent: 6035186 (2000-03-01), Moore et al.
patent: 6037999 (2000-03-01), Kunishima
patent: 6160572 (2000-12-01), Matsuura
patent: 6163684 (2000-12-01), Birleson
patent: 6169569 (2001-01-01), Widmer et al.
patent: 6233442 (2001-05-01), Koda et al.
patent: 6330290 (2001-12-01), Glas
patent: 6427068 (2002-07-01), Suominen
patent: 6484042 (2002-11-01), Loke
patent: 6591091 (2003-07-01), Vorenkamp et al.
patent: 6678012 (2004-01-01), Belotserkovsky
patent: 6714263 (2004-03-01), Cowley
patent: 6914437 (2005-07-01), Ibrahim et al.
patent: 6952564 (2005-10-01), Gannholm
patent: 6954625 (2005-10-01), Cowley
patent: 6970689 (2005-11-01), Khorram
patent: 6983136 (2006-01-01), Mason et al.
patent: 7051781 (2006-05-01), Grimm et al.
patent: 7054602 (2006-05-01), van der Pol
patent: 7110469 (2006-09-01), Shi et al.
patent: 7187916 (2007-03-01), Mo et al.
patent: 7299021 (2007-11-01), Perssinen et al.
patent: 7437139 (2008-10-01), Lo et al.
patent: 7702306 (2010-04-01), McMullin et al.
patent: 2001/0013132 (2001-08-01), Kudo et al.
patent: 2003/0157902 (2003-08-01), Khorram
patent: 2003/0171110 (2003-09-01), Shi et al.
patent: 2003/0176174 (2003-09-01), Seppinen et al.
patent: 2004/0002318 (2004-01-01), Kerth et al.
patent: 2004/0043737 (2004-03-01), Bienek et al.
patent: 2004/0106380 (2004-06-01), Vassiliou et al.
patent: 2004/0137870 (2004-07-01), Kivekas et al.
patent: 2005/0069056 (2005-03-01), Willingham
patent: 208470 (1986-06-01), None
patent: 473373 (1991-08-01), None
patent: 576082 (1993-06-01), None
patent: 883237 (1998-05-01), None
patent: WO99-16179 (1998-08-01), None
Aschwanden, “Direct Conversion—How to Make It Work in TV Tuners,” IEEE Transactions on Consumer Electronics, vol. 42, No. 3, Aug. 1996, pp. 729-738.
Ducourant et al., “A 3 Chip G&As Double Conversion TV Tuner System With 70 dB Image Rejection,” IEEE 1989 Microwave and Millimeter—Wave Monolithic Circuits Symposium, pp. 87-90, copyright, 1989.
Farmer, “Specifications for Tuner Design for Use in Cable Ready Television Receivers and VCRs,” IEEE Transactions on Consumer Electronics, vol. 36, No. 3, Aug. 1990, pp. 660-668.
Maas, “Microwave Mixers,” Artech House, Copyright, 1986, pp. 248-251.
Burns Lawrence M.
Gomez Ramon A.
McMullin Donald G.
Wakayama Myles
Broadcom Corporation
Le Lana N
Sterne Kessler Goldstein & Fox P.L.L.C.
LandOfFree
Apparatus and method for local oscillator calibration in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for local oscillator calibration in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for local oscillator calibration in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2735870