Patent ID: 8787507

Claim:
An apparatus comprising: a first amplifier configured to amplify an input signal; a mixer coupled to the first amplifier, the mixer configured to mix the amplified input signal outputted by the first amplifier with an oscillator signal, to provide a mixed signal; a first estimation circuit configured to measure voltage or power of the mixed signal; a first filter configured to filter the mixed signal to pass a first band of frequencies; a second amplifier configured to amplify an output of the first filter; a second estimation circuit configured to measure voltage or power at an output of the second amplifier; a second filter configured to filter the output of the second amplifier to pass a second band of frequencies narrower than the first band; and a state machine coupled to the first and second estimation circuits, the state machine configured to provide feedback to the first and second amplifiers and to the mixer, the state machine configured to increase a bias current of at least one of the first amplifier and the mixer, or decrease a gain of at least one of the first amplifier and the mixer, or both increase the bias current and decrease the gain, when the voltage or power measured by the first estimation circuit is greater than a first predetermined threshold and the voltage or power measured by the second estimation circuit is less than a second predetermined threshold, the state machine further configured to decrease a gain of at least one of the first amplifier, the second amplifier, and the mixer when the voltage or power measured by the second estimation circuit is greater than the second predetermined threshold.