Low profile, cavity backed spiral on thin ferrite ground plane for high power operation above 200MHz

This paper presents a small, low profile, 2" thick and 14" in aperture, spiral antenna backed by a thin ferrite ground plane. The antenna is intended to cover satellite (UHF TacSat (earth to LEO, 243-318 MHz)) and radio (PRC-148, PRC- 117F, PSC-5D (243-512 MHz)) communications. Miniaturization, ground plane treatment, and resistive loading techniques are considered, and a design optimization is carried out to determine the several material, shape and geometry parameters for best performance. In this paper, we carry out step-by-step design to achieve the challenging goals. Material treatments, inductive loading, resistive termination and impedance matching issues are addressed throughout the design. Measured and simulated data are then presented in the last section leading to impressive conclusions about the capability of materials to overcome the perennial issue associated with the ground plane's negative effects for conformal installations.