Design of PSIRA with focusing lens concentrating picosecond impulse on biological target

The Prolate Spheroidal Impulse Radiating Antenna (PSIRA) is used to radiate very fast pulses in a narrow beam with low dispersion and high field amplitude. The PSIRA is suitable to apply fast, intense pulses without direct contact, for skin cancer treatment. In this proposed work, SWB (Slanted Wire Biconical), EPH (Elliptical Profile Horn), TSVS (Tapered Slot Vivaldi Shape) and Tapered Arm Conical Plate (TACP) feed antenna configurations for Prolate Spheroidal Reflector (PSR) are explored to enhance spatial resolution on biological targets. The feed antenna is placed at the first focal point and the target is located at the second focal point of the PSR. Next, the near field focusing lens is designed to enhance the amplitude and the resolution of the wave incident at the second focus. A 10 layer Log periodic lens system is placed before the target to reduce the spot size of the focused field on the target. The delivery of subnanosecond pulses using reflector in conjunction with and without Log periodic lens system on the biological target is compared for all feed antenna configurations. Tapered Arm Conical Plate (TACP) fed PSR with the 10 layer Log periodic lens system greatly reduces the spot size to 0.75 cm along lateral direction and 1.5 cm along axial direction. The enhancement in spatial resolution is very suitable to reduce the damage to healthy tissues during cancer treatment.