Abstract: A low cost redundancy scheme for the radio frequency front end of a wireless hub that requires a minimum number of down converters and upstream receivers to implement. The redundancy scheme may also be used as a back-up support for any upstream channel that is provided with a greater amount of data than the other upstream channels.
Abstract: A controlled receive device is disclosed having an amplifier circuit, which receives an input signal, and a control circuit which receives the input signal and outputs a controlled signal to a receiver. The receiver outputs an output signal. A controller varies the gain of the amplifier circuit in response to levels of the controlled signal and the output signal. The control circuit outputs a controlled indicator signal indicative of a level of the controlled signal and the receiver outputs an output indicator signal indicative of the output signal level. The controlled indicator signal and the output indicator signal are compared using comparators, to respective reference or threshold levels for producing control signals used by the controller for varying the amplifier gain.
Type:
Grant
Filed:
December 29, 1998
Date of Patent:
November 27, 2001
Assignee:
Philips Electronics N.A. Corp.
Inventors:
Farbod Kamgar, Antoine J. Rouphael, Mariam Motamed
Abstract: An amplifier circuit (20) uses a series transistor (38) to couple the output of an amplifier (26) to a tuned circuit load (40) and to act as a variable resistance. In one embodiment for a multi-band receiver, multiple series transistors (38, 42) are switched for connecting different tuned circuits (40, 44) to the amplifier's output, and an activated one of the series transistors receives a gate voltage that varies its resistance so as to achieve gain control. An activated series transistors can also provide a resistance that stabilizes the amplifier (26).
Type:
Grant
Filed:
August 17, 1998
Date of Patent:
February 6, 2001
Assignee:
Motorola, Inc.
Inventors:
John Robert Siomkos, Edgar Herbert Callaway, Jr.