Abstract: 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-μm CMOS technology, and the output amplitude is about 65 mV at a 50 Ω load from a 1.8-V supply, the return loss (S11) at the output port is less than -10dB, and the chip size is 0.7 × 0.8 mm2, with a power consumption of 12.3 mW.

Key words: complementary metal oxide semiconductor