Silicon Laboratories Inc.
DYNAMICALLY RECONFIGURABLE FREQUENCY SELECTIVE ATTENUATOR FOR RADIO FREQUENCY RECEIVER FRONT END

Abstract:

A wireless device including a receiver circuit coupled to a radio frequency receiver node, a frequency selective attenuator including an inductor and a first capacitor coupled in series to the radio frequency receiver node, and a second capacitor coupled in parallel with the first capacitor. The first capacitor has a first capacitance based on a blocker frequency and the second capacitor has a second capacitance that linearizes the frequency selective attenuator. A method of linearizing a frequency selective attenuator including detecting presence of a blocker signal, activating and programming a capacitor of the frequency selective attenuator to reduce a strength of the blocker signal, determining a frequency difference between the blocker signal and a receive frequency, and coupling a second capacitor to the frequency selective attenuator to linearize the frequency selective attenuator when the frequency difference is no more than an attenuation threshold.