AGC window detector

Year	Description
1999	Invention patented by Shahriar Rabii on March 9th, 1999. Abstract: An AGC window detector that senses the sum of an in-phase (I) and a quadrature (Q) peak-to-peak signal swing and compares the signal to a reference voltage for producing a desired gain. The primary design issues of the detector is to achieve a very low voltage offset and a low power dissipation. The detector is part of the AGC circuits in the I/Q path of a wireless receiver. The signals I.sub.max, I.sub.min, Q.sub.max and Q.sub.min are the positive and negative peak values of the in-phase and the quadrature waveforms, respectively. They are generated by a peak detector. Thus the differential in-phase and the differential quadrature amplitudes are I.sub.max -I.sub.min and Q.sub.max -Q.sub.min,, respectively. A resulting differential in-phase signal is added to a resulting differential quadrature signal by the detector and compared to the reference voltage to determine if the resulting signal is greater than a maximum reference voltage, less than a minimum reference voltage or within the maximum and minimum voltages. A reference voltage generator creates the desired voltages within a desired tolerance.
Source: selected by the editor from original sources.

Invention: AGC window detector