Patent ID: 8614603

Claim:
An RF radio comprising: an automatic gain control (AGC) circuit having an input node to receive an RF signal and an output node that provides a gain-controlled RF signal, the AGC circuit further comprising: an amplifier stage to amplify the RF signal according to at least two incrementally discrete levels, wherein the amplifier stage has an input that couples the input node of the AGC and an output that couples the output node of the AGC, wherein each discrete level of the amplifier stage includes at least two separate differential transistor pairs, a collector resistor load connected to the at least two separate differential transistor pairs, a first emitter resistor load connected to a first of the at least two separate differential transistor pairs, and a second emitter resistor load connected to the a second of the at least two separate differential transistor pairs, wherein a gain of the discrete level is based on a ratio of the collector resistor load to one chosen from the first emitter resistor load and the second emitter resistor load; a peak detector to detect an amplitude of the RF signal; and a comparator responsive to the peak detector to compare the amplitude of the RF signal with a reference in order to provide a control signal to a control node of the amplifier to activate a respective one of the discrete levels according to the amplitude of the RF signal.