Baseband controlled multi-modulation pulse generator

Abstract

This paper introduces a simple yet effective circuit topology to directly generate and modulate UWB pulses using baseband signals. The same circuit can be used to achieve pulse position modulation (PPM), pulse amplitude modulation (PAM), on-off keying (OOK) and phase shift keying (PSK) by making changes in the baseband data. The method does not require the use of potentially expensive components like mixers, variable attenuators, switches or variable delays. The circuit employs a pair of anti-parallely mounted step recovery diodes (SRD) coupled to a pulse forming network. The use of the same component for both generation and modulation results in a lower component count and in turn, lower cost and power consumption.