The highly shortened conical helix

The highly shortened conical helix antenna is a leaky wave antenna that is inherently small yet displays high directional gain and good return loss, bandwidth, and circular polarization characteristics. As a consequence it can be used in lieu of the microstrip patch antenna, especially within confined spaces and in small arrays. This paper discusses the characteristics and details the effect of various physical variables on the performance of the highly shortened conical helix. Examples of successful designs which have found application in L-Band mobile satellite communications terminals are provided.