An azimuth of arrival detector based on a compact complementary antenna system

In this paper we propose a compact positioning system based on two pattern complementary antennas printed on the same substrate. The system is capable to discriminate the azimuth component of an impinging signal working with one RSS-based technique. The unique features of the ellipse and superellipse geometry, applied to a effective design tool proposed by the authors, makes possible the design of both directive and omnidirectional radiators. The complementarity is a perfect requisite for a MUSIC-based angle of arrival detector. The antenna system is fabricated with a low-cost FR4 dielectric substrate and exhibits a matching of around -20 dB dB at center frequency of 2.47 GHz for both the antennas, within an impedance bandwidth of 100 MHz, while maintaining the compact dimension of less than 50 x 50 mm. The directional antenna shows a CP directivity of 6.0 dB and a Half Power angle of about 50°, while the omni-directional radiator shows a maximum at θo = 55°, with an Θhp of 30° . A set of localization experiments demonstrate the goodness of the proposed system, which shows a mean error of 11.94° degree.