Patent ID: 7433431

Claim:
In a wireless receiver where a radio frequency signal is received, downconverted, and processed into in-phase (I) and quadrature (Q) signal paths, a method of automatic gain control (AGC) comprising: (a) at a specified stage in an I/Q baseband strip containing multiple automatic gain control (AGC) stages, each of the AGC stages having locally generated control signals associated therewith: detecting respective I and Q output signals received from respective I and Q variable gain amplifiers (VGAs) associated with the specified AGC stage to produce a detected I and Q signal, the detecting comprising: passing the respective I and Q output signals through respective high pass filters (HPFs) to remove direct current offsets, rectifying each of the respective I and Q filtered output signals, adding the respective I and Q rectified filtered output signals in an operational amplifier, and passing the added I and Q rectified filtered output signal through a low pass filter (LPF) to produce the detected I and Q signal; generating at least one digital counter signal responsive to differences between the detected I and Q signal and at least one reference signal; generating a control signal by multiplexing the at least one digital counter signal with the at least one reference signal; and controlling the respective I and Q VGAs with the control signal; and (b) repeating (a) through each AGC stage.