Multiplexers and Duplexers Having Active Cancellation for Improved Isolation between Transmit and Receive Ports

摘要

A multiplexer is configured to receive a transmit signal from a first amplifier and to provide a receive signal to a second amplifier. A leakage signal is transmitted to a path leading to the second amplifier. A first device configured to provide a portion of the transmit signal to an active cancellation circuit, the active cancellation circuit configured to substantially invert the phase of the portion of transmit signal and to attenuate the amplitude of the portion of the transmit signal. A second device configured to receive the portion of the transmit signal from the active cancellation circuit, and to combine the portion of the transmit signal from the active cancellation circuit with the leakage signal prior to an input to the second amplifier.

主权项

1. An apparatus, comprising:
a multiplexer configured to receive a transmit signal from a first amplifier and to provide a receive signal to a second amplifier, wherein a leakage signal is transmitted to a path leading to the second amplifier; a first device configured to provide a portion of the transmit signal to an active cancellation circuit, the active cancellation circuit configured to substantially invert the phase of the portion of transmit signal and to attenuate the amplitude of the portion of the transmit signal; and a second device configured to receive the portion of the transmit signal from the active cancellation circuit, and to combine the portion of the transmit signal from the active cancellation circuit with the leakage signal prior to an input to the second amplifier.