PulsON second generation timing chip: enabling UWB through precise timing

In 1999, Time Domain Corporation (TDC) introduced the first ultra-wideband (UWB) radios using full custom integrated circuits, the PulsON 100 chipset. This paper describes TDC´s recently developed second generation precision SiGe timing chip. PulsON time modulated UWB radios are composed of three basic components: (1) a precise timing subsystem; (2) a correlator subsystem (often consisting of multiple correlators); (3) a digital baseband signal processing and system control subsystem. Precise timing is crucial in the design of the PulsON UWB radios. Similar to TDC´s earlier T1 chip, the T2 timing generator accurately places pulses within very small windows (100 ns windows for the T1, as small as 50 ns for the T2). These timing chips use a high speed counter to set a coarse delay in 800 ps quantized steps followed by an IQ phase delay circuit that sets a fine delay on top of the course delay to about 3 ps resolution. The T2 positions pulses to an accuracy of better than 3 ps with a jitter of less than 10 ps. The T2 IC, a mixture of analog, digital, and RF functions, operates up to a clock rate of 1.228 GHz, and consumes a maximum of 0.5 W.