Pulse or digital communications – Transceivers – Modems
Reexamination Certificate
2004-07-01
2009-06-09
Tran, Khai (Department: 2611)
Pulse or digital communications
Transceivers
Modems
C455S302000
Reexamination Certificate
active
07545857
ABSTRACT:
A communications receiver architecture characterized by a relatively low intermediate frequency (IF) and a polyphase filter. The receiver includes an input amplifier coupled to a carrier signal. Respective I and Q demodulators are coupled to the output of the input amplifier. A quadrature local oscillator (LO) generator provides respective LO_I and LO_Q inputs to the I demodulator and LO_Q inputs to the I demodulator and to the Q demodulator. The quadrature LO generator is driven by a phase-locked LO, and the LO frequency is such that an IF of, in one embodiment, approximately 1 MHz results. The I demodulator and Q demodulator outputs are applied through respective AID converters to a polyphase filter. The polyphase filter outputs are then processed by a digital I/Q demodulator. Although a low IF is not generally understood to promote the image rejection performance of a receiver, substantial image rejection is afforded by the polyphase filter, thereby enabling the receiver to be realized almost entirely as a monolithic integrated semiconductor device.
REFERENCES:
patent: 4696055 (1987-09-01), Marshall
patent: 4723318 (1988-02-01), Marshall
patent: 5469126 (1995-11-01), Murtojarvi
patent: 5715529 (1998-02-01), Kianush et al.
patent: 5812823 (1998-09-01), Kahle et al.
patent: 5926646 (1999-07-01), Pickett et al.
patent: 5974306 (1999-10-01), Hornak et al.
patent: 6035186 (2000-03-01), Moore et al.
patent: 6061711 (2000-05-01), Song et al.
patent: 6278870 (2001-08-01), Davie et al.
patent: 6347123 (2002-02-01), Mathe et al.
patent: 6778594 (2004-08-01), Liu
patent: 0 797 292 (1997-09-01), None
patent: WO 99/16179 (1999-04-01), None
Communication from the EPO dated Nov. 3, 2004 enclosing 1) European Search Report Application No. EP 01 25 0210, Search Completed dated Oct. 6, 2004, Munich; and 2) Abstract (total 4 pages).
Minnis, B., et al. “A Low-IF, Polybase Receiver for DECT.” ISCAS 2000, IEEE International Symposium on Circuits and Systems, vol. 1, May 2000, pp. 160-163.
Crols, J., et al., “Low IF Topologies for High-Performance Analog Front Ends of Fully Integrated Receivers.” IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, IEEE, Inc., New York, US, vol. 45, No. 3, Mar. 1, 1998, pp. 269-282.
Specification of the Bluetooth System—Core; v1.0B; Dec. 1, 1999;pp. 1-1082.
iAPX 86, 88, 186 and 188 User's Manual—Programmer's Reference; 1985; Cover Page and pp. 3-1-3-6.
Broadcom Corporation
Tran Khai
LandOfFree
Receiver architecture employing low intermediate frequency... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Receiver architecture employing low intermediate frequency..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Receiver architecture employing low intermediate frequency... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4146929