A new GPS hexafilar slot antenna

This paper presents a new GPS slot antenna consisting of six quarter-wavelength resonant slots. Each of the six resonant slots is rolled a half-turn around the cylindrical laminate and maintains constant phase relation to each other to form a right-hand circular polarization to receive GPS satellite signals. The printed cylindrical slot antenna presented is useful in applications where low-profile installation is required on a highly dynamic aircraft. This new printed GPS antenna provides compact size, low cost, ease of mass production, near-hemispherical radiation coverage and circular polarization properties. Experimental results show that the new hexafilar antennas have a 3 dB beamwidth of more than 120/spl deg/ and a front-back ratio of more than 15 dB.