Wideband, high-amplitude, pulsed antennas for medical therapies and medical imaging

Focusing Impulse Radiating Antennas allow the application of intense electric fields to biological tissue with centimeter spatial resolution. At low electric field strength, the scattered electromagnetic waves from the focal volume can be used to obtain information on the complex permittivity of the tissue at this location. Since the permittivity of tumor tissue varies considerably from that of healthy tissue, this will allow us to explore the growth and composition of tumors. At high electric fields, cell functions are affected, resulting in effects which may lead to new medical therapies. Two types of antennas with prolate-spheroidal reflectors are being studied, experimentally and through modeling, with respect to their focusing characteristics. As the pulse source for the antennas, a 150 ps, high voltage (>100 kV) pulse generator has been developed that is also used to explore the biological effects of wideband pulses.