Active feedback interference cancellation in RF receiver front-ends

Autor: Stefan Heinen, Tobias D. Werth, Christoph Schmits
Rok vydání: 2009
Předmět:
Zdroj: 2009 IEEE Radio Frequency Integrated Circuits Symposium.
DOI: 10.1109/rfic.2009.5135562
Popis: A feedback interference cancellation circuit is presented that uses a control loop to reject blockers in wireless receivers. The concept is based on a translational loop which subtracts a blocker replica in a feedback loop fashion. In contrast to feedforward methods loop selectivity does not depend on exact gain matching of two paths but on the open loop gain which is easier to adjust. The concept is described including the theoretical derivations of the transfer function and stability. Measurements from a prototype chip in 65nm CMOS are presented showing the feasibility of active feedback cancellation. In a desensitization scenario, gain drops by more than 12 dB for a −15dBm blocker at 20MHz offset without feedback interference cancellation while a gain degradation of merely 3 dB is measured with feedback interference cancellation enabled.
Databáze: OpenAIRE