A 16 GHz Differential Electrical Balance Duplexer Based on Magnetic-Flux Cancelation for M2M Full-Duplex Communication

This paper presents a 16GHz fully differential electrical balance duplexer (EBD) for enabling full-duplex communication in rotary machine-to-machine (M2M) interfaces. The EBD employs a differential 4-coil 180° hybrid structure with inherent magnetic flux cancelation to achieve >30dB TX-to-RX isolation over 4GHz bandwidth. TX-to-ANT and ANT-to-RX loss is 4.2dB and 4.9dB, respectively. TX-to-ANT input P1dB is larger than +17dBm whereas TX-to-ANT/ANT-to-RX IIP3s are +28.2/+31.4dBm, respectively. To the best of our knowledge, this work achieves the widest isolation BW (fractional) and highest IIP3 among EBDs and circulators reported above 10GHz.