Transient radiation properties of an integrated equiangular spiral antenna

Abstract

Self-complementary two-arm equiangular spiral antennas were fabricated on silicon-on-sapphire substrates. Picosecond photoconductive pulse generation and sampling were used to investigate their transient radiation properties. Results are presented on transient response, bandwidth, polarization, and radiation pattern. The equiangular spiral antenna is found to be highly efficient, and its transient response exhibits a frequency sweep which is a direct consequence of the antenna structure. In this mode of excitation, the antenna remains circularly polarized, and the pattern for radiation through the substrate is quite broad.