A thin cavity-backed Archimedean slot spiral for 800-3000 MHz band coverage

We show that cavity-backed slot spirals (rather than printed) are particularly attractive for conformal applications. Since slot radiation is enhanced by the presence of a shallow metal backed cavity, very thin (less than a 1/4 inch thick) antennas can be considered without compromising the spiral´s broadband performance. A specific design proposed by Nurnberger and Volakis (see 19th. Meeting and Symposium of Antenna measurement Techniques Association, Boston, Massachusetts, 1997) is considered for analysis and improvement.