“…With respect to radar technology, the most advanced concepts appear to be ultra-wideband microwave imaging via space-time beamforming [Xu et al 2005;Davis et al 2005], confocal microwave imaging [Fear et al 2002;Yun et al 2005] and near field synthetic focusing [Benjamin et al 2001]. Studies of microwave tomography also exist and include reports by Bolomey et al [1982Bolomey et al [ , 1983Bolomey et al [ , 1985, Liewei et al [2002], Souvorov et al [2000], Bulyshev et al [2001], Meaney et al [2000Meaney et al [ , 2003, Ciocan et al [2004], among others. Most of these efforts (either radar or tomography) are occurring at the prototyping stage where the goal has been to identify and optimize the important design considerations rather than report on the electrical characteristics of breast tissue per se.…”