Multi Octave Band Spiral Antenna Using Hybrid Loading for Phase Comparison Direction Finding System

This paper discusses a Hybrid loaded low profile multi octave band spiral Antenna for phase comparison direction finding (PDF) applications. Designed an archimedian spiral antenna covering frequency range from D to J band, simulated and optimised the parameters using simulation software. Inductive and tapered dielectric loadings were incorporated for miniaturisation of antenna. The antenna was fabricated, assembled and achieved 41% miniaturisation with minimum gain of -10 dBic at lowest frequency of operation. This antenna finds application in PDF systems for airborne platforms.