A Compact Circularly Polarized Conformal GPS Antenna for Vehicle Tracking Applications

Proposed in this paper is a Circularly Polarized (CP), conformal antenna, which is excited using the Co-Planar Waveguide (CPW)-feeding arrangement, for vehicle tracking applications. The designed antenna footprint is 39 mm × 30 mm and operates at 1.575 GHz, which is the center frequency of the GPS L1 frequency band. It exhibits a wide -10 dB bandwidth extending from 1.38 GHz to 1.8 GHz. Thus, covering the GPS L1 bandwidth of 15.345 MHz. To attain circular polarization, an asymmetric CPW ground plane was designed in addition to protruding an inverted hook-shaped strip from the left CPW ground plane. At 1.575 GHz, the antenna possessed an axial ratio of 1 dB at the boresight direction with 3 dB-AR bandwidth of 240 MHz. Based on the presented specifications, the proposed antenna might be a good candidate for vehicle tracking applications.