A high linearity mixer using enhanced derivative superposition method for application in LTE small cell basestation

The proposed mixer was fabricated in TSMC 1P6M 0.18 um CMOS process. This mixer is intended for application in LTE small cell base station. The circuit architecture is based on the Gilbert mixer. The folded technique allowed the bias current of the trans-conductance stage and that of the switching stage to be different. A new type of inverter amplifier with enhanced derivative superposition method was employed to improve the linearity. The simulation shows that it can attain satisfactory performance on conversion gain and linearity. The mixer can convert 100 MHz inter-mediate frequency to 1.8 GHz radio frequency. The post-layout simulation result shows that a conversion gain of 8.1 dB, an input third-order intercept point (IIP3) of 15.8 dBm, supply voltage of 1.2 V, and a power consumption of 14.28 mW.