Switching resonator filter circuits and methods

摘要

The present disclosure includes switching resonant filter circuits and methods. In one embodiment, a circuit includes a plurality of resonant switching circuits arranged in a three (3) or four (4) element PI network. In one embodiment, an undesired signal frequency is applied to two resonant switching circuits and a carrier frequency of an RF signal is applied to the other two resonant switching networks so that the network attenuates the undesired signal frequency and passes the carrier frequency. In another embodiment, the resonant switching circuits are configurable to shift a peak impedance so that undesired signals may be attenuated.

主权项

1. A circuit comprising:
a first resonant switching circuit having a first terminal coupled to a first output terminal of a low noise amplifier to receive an RF signal; a second resonant switching circuit having a first terminal coupled to the first output terminal of the low noise amplifier; a third resonant switching circuit having a first terminal coupled to a second terminal of the first resonant switching circuit, wherein the first resonant switching circuit is configured to produce a low impedance at a carrier frequency of the RF signal and a high impedance at a first frequency, wherein the second resonant switching circuit and the third resonant switching circuit are configured to produce a high impedance at the carrier frequency of the RF signal and a low impedance at the first frequency, wherein the first resonant switching circuit, the second resonant switching circuit, and the third resonant switching circuit are M-path circuits, wherein the M-path circuits comprise an in-phase switched capacitor circuit and a quadrature switched capacitor circuit, and wherein the in-phase switched capacitor circuit is selectively coupled to the quadrature switched capacitor circuit by a first transconductance circuit and the quadrature switched capacitor circuit is selectively coupled to the in-phase switched capacitor circuit by a second transconductance circuit.