Physically small and adjustable double-ridged horn antenna for biomedical UWB radar applications

Biomedical applications of ultra-wideband radar promise a very important means to remotely characterise tissues and organs. The acquisition of such physiological signatures requires small and efficient antennas, designed for ultra-wideband frequency operation. We have designed and characterised physically small and adjustable double-ridged horn antennas for frequencies from 1 to 10 GHz. The miniaturisation of the radiating elements was accomplished by immersion into a high permittivity liquid dielectric. The effect of dielectric scaling on size, input matching, radiation patterns, and gain has been evaluated by comparison with a double-ridged horn antenna designed for operation in air.