When using electrical-balance duplexers (EBDs) to provide RF self interference cancellation for in band full duplex, in-band distortion produced by nonlinear CMOS switches in the duplexer cause distortion that limits the headroom for additional self interference cancellation in subsequent cancellation schemes in the transceiver. A prototype EBD is fabricated in 0.18µm SOI CMOS to investigate the dynamic range limitations of a transceiver architecture for next generation wireless systems that supports in band full duplex and legacy FDD. Measurements show -85dBm in band distortion at +10dBm TX input power, enough for short-range links at 10MHz BW.