A planar slot spiral for multi-function communications apertures

A slot spiral antenna and its associated feed are presented for conformal mounting on a variety of land, air, and sea vehicles. By exploiting the inherent broadband behavior, good pattern coverage and polarization generality of the spiral antenna, a conformal antenna which may be concurrently used for cellular, digital personal communications (PCS), global positioning (GPS), and intelligent vehicle highway systems (IVHS), as well as wireless LAN networks, has been developed. A key requirement for achieving such broadband behavior (800-3000 MHz) is the availability of a frequency-independent planar feed and balun. Additionally, high quality, very broadband spiral arm terminations and cavity and waveguide mode suppression are also very important. After a general description of the slot spiral antenna and the above advances, pattern and gain data are presented across the entire frequency range of operation.