Performance Enhancement of A Compact Archimedean Spiral Antenna for 2-18 GHz

A hybrid technique of using an electromagnetic (EM) absorbing material and a set of resistors are proposed to improve the low frequency matching and axial ratio of an Archimedean spiral antenna for
$2-18\ GHz$
. A cavity of depth 5 mm is maintained to make the structure extremely compact. Simulations are performed to analyze the effects of these approaches separately. A Wideband matching and polarization purity are observed over the entire frequency range with a maximum right-hand circular (RH) gain of 8.2 dBiC.