Radioengineering (Sep 2006)
A Self-Complementary 1.2 to 40 GHz Spiral Antenna with Impedance Matching
Abstract
This paper describes a design of the Self- Complementary Spiral Antenna (SCSA) which consists of a spiral antenna and a wideband impedance transformer. The spiral antenna and the transformer are designed separately due to computing demands. New knowledge about current distribution on the spiral antenna and influence of higher numbers of wavelength in circumference is presented. The novel transition between feeding and radiating antenna structure are optimized in the frequency range 1.2 to 40 GHz. The meaning of the transition in the paper includes the impedance as well as the geometry transforming of the structure. The antenna is suitable for wideband illuminating of a parabolic reflector due to relatively constant phase center and radiation pattern with frequency.
