2.4/5.7 GHz Dual-Band High Linearity Gilbert Upconverter Utilizing Bias-Offset TCA and $LC$ Current Combiner

A 2.4/5.7 GHz dual-band Gilbert upconversion mixer is demonstrated using 0.35 mum SiGe BiCMOS technology. A bias-offset cross-coupled transconductance amplifier (TCA) is employed in the intermediate frequency port for the linearity improvement. The dual-band LC current combiner and the output shunt-shunt feedback buffer amplifier are in the radio frequency (RF) port. The mechanisms of the high linearity upconverter and the design flow of the dual-band LC current combiner are established in this letter. The dual-band upconverter has conversion gain of 1.5/-0.2 dB, OP
_1dB
, and of -10.5/-9 dBm, and OIP
₃
of 12/13 dBm for IF=100 MHz, RF 2.4/5.7 GHz, respectively.