A 12.5-Gb/s Pulse Modulator with 6.5-ps FWHM Using 0.1-μm InP HEMTs for Ultra-Wideband Impulse Radio Communications

We developed an ON/OFF pulse modulator IC using 0.1-mum-gate-length InP HEMTs for ultra-wideband impulse radio (UWB-IR) communications systems. The IC generated extremely short pulses whose full width at half maximum (FWHM) were 6.5 ps. Furthermore, our new circuit architecture that retimes output pulses at both rising and falling edges made the IC robust against timing fluctuations or jitter. The output pulses had very small jitters of 256 fs rms and 1.3 ps p-p and thus had little degradation from intersymbol interference (ISI) when a 231-1 length pseudo random bit stream (PRBS) at a bit rate of 12.5 Gb/s was input. The pulse modulator can be used to construct an ON/OFF keying transmitter based on UWB-IR architecture that sends more than 10 Gb/s of data in the W-band (75-110 GHz) and above.