Effects of Dielectric Substrate on Performance of UWB Archimedean Spiral Antenna

This paper presents the design of the Archimedean Spiral Antennas (ASA) backed by a metal plate. The dimension of the spiral arm was designed to operate between 3.1 - 10.6 GHz and different permittivity of the dielectric substrate was employed between the spiral arm and the backing plate with specified electrical thickness of lambda(g)/4 at the lowest frequency range. The CST simulated results shows that when the dielectric permittivity, epsilon(r) increases, the performance of the ASA in terms of return loss, axial ratio, efficiency, pattern and gain deteriorates.