Switching Mode Power Amplifier for Fully Digital RF Transmitter at 3.6 GHz in 22 nm FD-SOI CMOS

Post-layout simulation results of a current mode switching mode power amplifier (CM-SMPA) in 22 nm FD-SOI CMOS for a fully digital RF transmitter with a peak output power of 23.51 dBm (224.4 mW) at 3.6 GHz are presented. The CM-SMPA is driven by a pulse-width (PW) and pulse-position (PP) modulated signal for amplitude and phase control. To increase the amplitude dynamic range, the conductance (G) of the switches is also modulated. For a 64-QAM signal with 112.5 MBd, an error vector magnitude (EVM) of −32.50dB with a maximum adjacent channel leakage ratio (ACLR) of −40.81 dB in the neighbor channel is achieved. The average total efficiency and drain efficiency are 24.93 % and 32.12 % respectively. The large signal bandwidth potential of this transmitter concept is shown by a simulation of a 450 MBd 64-QAM with a channel bandwidth of 675 MHz.