A 28.1GHz ultra-low-power SHM with AC-DC spliting LC-tank and an analysis of the switch-conversion efficiency

This paper presents a 28.1GHz ultra-low-power down-conversion sub-harmonic mixer (SHM). Two novel circuit topologies are proposed. First circuit introduces an AC-DC signal splitting LC-tank based on the conventional mixer. By utilizing the LC-tank, the resistor for small signal is enhanced and just one stage transistor exists between a voltage supply (VDD) and ground (GND). A Single-NMOS switch is employed in the second novel circuit to simplify the circuit structure and to reduce the chip size. To improve the conversion gain, switching conversion efficiency is analyzed. The circuit was simulated with the GLOBALFOUNDRIES 56-nm SOI CMOS process. Simulation results show that the conversion gain is 4 dB with a dc current of only 600 μA at a supply voltage of 500 mV for the mixer core.