A new GPS quadrifilar helix antenna

This paper discusses the design and measurement of a new printed half wavelength quadrifilar helix antenna. We use infinite microstrip baluns to feed the helical antenna. This feeding technique reduces the antenna's physical size and provides an ease of mass production. Experiment results show that the printed volute antenna has a 3 dB beamwidth of more than 145/spl deg/ and a front-to-back ratio of more than 20 dB.