Time-Interleaved Digital-to-Analog Converters for UWB Signal Generation

In this paper, a differentially encoded time-interleaved digital-to-analog converter (TIDAC) structure for ultra-wideband (UWB) signal generation is presented. We show that the output spectrum of the TIDAC is identical to the output of a DAC running at a higher sampling rate. To support the mathematical derivations, the UWB signal generator has been implemented on FPGA hardware and measurements have been taken for a sinusoidal wave, a Gaussian UWB pulse shape and for a UWB OFDM signal. The measurements show that, compared to the single-channel DAC, the mirror images around the sampling frequency can be reduced by about 30 dB and the analog interpolation filter design is simplified.