ABSTRACT

Information Converters ............................................................................88 3.6.6 UWB Signal Real-Time Time Stretching, Time Lens, or Time Imaging .................90

3.7 Target Adaptive UWB Radar Transmitter Requirements .............................................. 93 3.7.1 Targets and Signal Modulation Objectives .......................................................... 93 3.7.2 Direct Digital Synthesis .......................................................................................... 94

3.7.2.1 Traditional Signal-Generation Methods ................................................ 94 3.7.2.2 Frequency Up-Conversion ....................................................................... 94

3.7.3 Analog Filtering ...................................................................................................... 96 3.7.4 Digital Logic Signal Generation and Transmitters ............................................ 96 3.7.5 Analog-Digital Signal Synthesis .......................................................................... 97

Imagine a radar that can identify targets by their reflected signal spectra and adjusting its transmitted signal to match a specific class of targets. The advanced ultrawideband (UWB) radar evolves the technology from a passive detector of reflected electromagnetic signals to an active sensor for finding special targets. This chapter introduces the concepts and technology needed to build this system.