An FD/FDD transceiver with RX band thermal, quantization, and phase noise rejection and >64dB TX signal cancellation

Abstract

A transceiver system with active cancellation of the TX signal for full duplex (FD) or frequency division duplex systems (FDD) is presented. A replica cancellation digital-to-analog converter and highly linear receiver with +25dBm OOB IIP3 enable FDD operation without a duplexer at TX power up to +17dBm, FD operation without a circulator up to +5dBm, and FD operation with a circulator up to +13dBm. In addition to providing over 64dB of RF cancellation for a 20MHz modulated TX signal, the front-end demonstrates techniques to cancel noise sources in the RX band, including 3dB reduction of the thermal noise from the self-interference cancellation circuits, >25dB cancellation of quantization noise from the digital TX, and >20dB cancellation of TX LO phase noise in the RX band.