A 3-5 GHz TH-UWB transmitter in 0.18-mu m RF CMOS technology

An RF transmitter is proposed for 3-5 GHz time-hopping ultra wideband (TH-UWB) wireless applications. The transmitter consists of a 4-GHz oscillator, a switch with a controllable attenuator and an output matching circuit. Through controlling the low frequency signals with time-hopping pulse position modulation (TH-PPM), the circuit supplies TH-UWB signals and can directly drive an antenna by a transmission line. The transmitter was implemented in a 0.18-mu m CMOS technology; the output amplitude is about 65 mV at a 50 Omega load from a 1.8-V supply, the return loss (S-11) at the output port is less than -10 dB, and the chip size is 0.7 x 0 8 mm(2), with a power consumption of 12.3 mW.