A low cost tri-band microstrip patch antenna for GPS application

This paper presents a novel design of a tri-band microstrip patch antenna for global positioning system (GPS) receiver. The antenna uses a low cost FR-4 substrate. It employs an open loop resonator (OLR), a split rectangular slot (SRS) and a stub at the non-radiating edge to achieve multi-band response. The design is simple and does not involve stacking of substrates. Simulations are done in Ansys HFSS to study the return loss, radiation pattern and gain of the antenna. The proposed antenna is resonant at GPS frequencies viz. 1.58 GHz (L1 band), 1.208 GHz (L2 band) and 1.129 GHz (L5 band). The -10 dB impedance bandwidth measured in L5, L2 and L1 bands are 1.1231-1.1356 GHz (1.107%), 1.1987-1.2221 GHz (1.603%) and 1.5831-1.5893 GHz (0.394%) respectively. The antenna gain is 4.03 dBi, 5.6 dBi and 2.31 dBi in the three resonant frequencies viz. 1.129 GHz, 1.208 GHz and 1.58 GHz respectively. The antenna is found to have stable radiation pattern. It has a wide beamwidth in the upper hemisphere, which is necessary for GPS signal reception. The antenna is linearly polarized in all the three GPS bands and has an efficiency of 88% in the lower GPS bands. The antenna is fabricated and performance studied by experiments. The simulation results agree reasonably with measurement results.