Tappered Spiral Helix Antenna
This paper presents the aspects related to the design and development of a tapered spiral helix antenna covering the frequency range 1.2-18GHz. It is a compact state-of-the-art circularly polarized antenna, which works over multi-octave frequency bandwidth (1.2-18 GHz).The antenna size has been reduced by 50 percent with respect to conventional spiral antenna used for same frequency band. Spiral helix antenna consists of a spiral antenna and a helical antenna where the outer ends of spiral antenna are terminated with a helix. The helix is placed with its axis at 90 degrees to the spiral lies behind it and is designed to produce circularly polarized radiation over a range form 1.2-18GHz.