Patent ID: 6356603
Filing Date: 2002-03-12
Classification: H04B

Abstract:
A method for controlling an integrated multi-mode bandpass sigma delta radio frequency receiver subsystem comprising the step of:mixing a first intermediate frequency (IF) signal with a programmable local oscillator signal to provide a programmable second IF signal; amplifying the second IF signal using an amplifier; and controlling the gain of the amplifier using an AGC to provide an output signal having variable bandwidth; converting the output signal into in-phase and quadrature output digital signals using a multi-mode sigma-delta analog-to-digital signal converter; reducing the frequency of the in-phase and quadrature output digital signals to provide a decimated signal; removing any undesired aliasing signal components from the decimated signal to provide a filtered signal; formatting the filtered signal into a plurality of digital words for use by a digital signal processor; and controlling the gain of the multi-mode sigma-delta analog-to-digital signal converter using an automatic gain control signal adjustable by internal and external control signals.