Design of a novel circularly polarized reactive stub loaded microstrip patch antenna for altimeter applications

This paper investigated and presented a novel reactive stub loaded square microstrip patch antenna with circularly polarization at C-Band. A square microstrip patch antenna is designed and loaded with inductive and capacitive reactive stubs, two stubs provides near to 90 degree phase quadrature for circular polarization. The antenna is designed on PTFE substrate (ε
_r
=2.2, tan δ =0.0009) with thickness of 61 mil. Optimized the design using commercial EM software, feed point location and stub length & widths are varied to achieve optimum reflection coefficient and circular polarization bandwidths. The antenna shows 7.2% impedance bandwidth, 3.3% of Axial Ratio (AR) bandwidth and 5.93dBiC peak gain. It is proposed to use for altimeter applications.