Ultrawideband Power-Switchable Transmitter With 17.7-dBm Output Power for See-Through-Wall Radar

In this brief, a fully digitized pulse generator with programmable pulse number and width is used as an ultrawideband (UWB) pulse transmitter with 17.7-dBm output power for see-through-wall (STW) radar. A fully differential operation broadband CMOS power amplifier (PA) with a power-switchable mode and fast settling time for pulse radar is presented, achieving excellent power consumption, considerable output power, and a -3-dB bandwidth from 3.6 to 6.6 GHz. The on-chip transformer is used for impedance transformation in the output and converting signals from the differential to single ended. Fabricated in a 65-nm standard CMOS process, the operating carrier frequency range of the transmitter covers 3.2-5.8 GHz and the pulsewidth can be adjusted from 0.75 to 1.2 ns. The number of pulses varies from 4 to 1. At 10-MHz pulse repetition frequency (PRF), the maximum peak-to-peak voltage of the transmitter output pulse reaches 3.8 V with 50- $\Omega $ load, and the corresponding pulsewidth is 0.75 ns. The equivalent power is 17.7-dBm after calibration, and the average power consumption is only 22.5 mW.