Generation of a highly focused electromagnetic field in a lossy biological medium by controlling the phase and time excitation of the microwave sources

A focused electromagnetic field is generated in a layered cylindrical biological tissue model, by using a large number of concentrically placed waveguide applicators and pulsed signals of short pulse width, with a high frequency carrier. To this end, constructive phase interference and time coincidence of pulse modulated microwave signals principles are applied. Numerical results are computed and presented for a three-layer geometry, 20 cm in diameter, irradiated by an annular waveguide array, using 30 elements.