ABSTRACT
In this chapter, the authors present reported techniques in the design of antenna elements, array topologies, and relevant wall effects, and some of the important antenna-related system integration issues. In particular, they concentrate on the following two classes of antennas: wideband microstrip antennas with a bandwidth of 25% to about 50% and ultra wideband (UWB) antennas with a minimum of 2:1 or a larger operating band. The propagation characteristics of wideband and UWB signals are essential for the optimal design and implementation of through-the-wall radar imaging (TWRI) systems. TWRI research area has recently received a considerable attention for sensing and imaging of moving and stationary targets through visually opaque obstacles such as walls. Numerical methods like the finite-difference time-domain method can be used to more accurately estimate transmission losses of composite walls, like cinder-block and sheet-rock walls.
