Design of a broadband Archimedean spiral antenna above a thin modified Electromagnetic Band Gap substrate

This paper presents the design of a low profile, lightweight, broadband spiral antenna for airborne applications. A thin modified electromagnetic band gap substrate with load is used as reflector for an Archimedean spiral antenna. This new loaded electromagnetic band gap (LEBG) substrates has very wideband radiation characteristics and has an easier realization than the mushroom-like surface. The conception of the antenna has been validated by measurements. Thickness and weight of this new antenna is greatly reduced and radiation characteristics are better compared to a conventional spiral antenna with unidirectional beam.