Leakage Cancellation with Adaptive Delay Filter

In an Frequency-Division Duplexing (FDD) transceiver, a high power transmitted signal can leak into the RX chain due to limited isolation of a duplexer. Such signal is known as TX leakage and can seriously affect the performance of the receiver. A transmitter leakage canceller structure is proposed in this paper in order to improve isolation between the transmitter and receiver. The simulations show the proposed structure increases the isolation of a Surface Acoustic Wave (SAW) duplexer by more than 25 dB in 20 MHz bandwidth.

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