Development of compact three-dimensional unidirectional ultra-wideband antennas for portable microwave head imaging systems

Portable head imaging systems spurs on new designs of compact antennas having ultra-wideband (UWB) operation with unidirectional radiation patterns in the low microwave frequencies. This paper describes the limitations of previously designed three-dimensional (3D) antennas proposing a more compact antenna with 79% fractional bandwidth with stable directional radiation patterns. At least 50% size reduction compared to the previous proposed antennas is achieved enabling utilization of more elements in the antenna array of the imaging system.