Analysis, design, and fabrication of Archimedean spiral antennas

The uses for wideband antennas include wideband measurement systems, spread spectrum communications systems, feeds for reflectors and elements in wideband arrays. Here, wideband antennas are discussed and Archimedean spiral antennas are found to be appropriate elements for use in a new type of wideband array referred to as the wideband switched array. The design of an Archimedean spiral and a necessary wideband balun transformer feed structure are presented. To aid in the design, the Electromagnetic Surface Patch Code (ESP) developed by Ohio State University is used. The spiral and feed structure are constructed and measured results are compared to predictions obtained by ESP.