An IR-UWB Pulse Generator using PAM Modulation with Adaptive PSD in 130nm CMOS Process

Abstract

This paper proposes an adaptive pulse generator using Pulse Amplitude Modulation (PAM). The circuit was implemented with eight Pulse Generator Units (PGUs) to produce up to eight monocycles per pulse. The number of monocycles per pulse is inversely proportional to the Power Spectrum Density (PSD) bandwidth in the Impulse Radio Ultra-Wide Band (IR-UWB). The complete circuit contains two pulse generator blocks, each one composed by eight PGUs to build a rectangular waveform at the output. The PGU has been implemented with Edge Combiners High (ECH) and Edge Combiners Low (ECL) to encode the information. Each Edge Combiner has a high impedance circuit that is selected by digital control signals. The circuit has been simulated, showing an output pulse amplitude of $\approx 70\mathrm{mV}$ for the high logic level and an amplitude of $\approx 35\mathrm{mV}$ for the low logic level, both at 100 MHz Pulse Repetition Frequency (PRF). This produces a mean pulse duration of $\approx 270\mathrm{ps}$, a mean central frequency of $\approx 3.7\mathrm{GHz}$ and a power consumption less than $0,22\mu \mathrm{W}$. The pulse generator block occupies an area of 0.54mm2.