Circularly polarized patch antenna with an L-shaped probe fed by a microstrip line

A circularly polarized (CP) circular patch microstrip antenna with a cross slot using an L-shaped probe fed by a microstrip line is designed and measured. With the single L-probe, the impedance bandwidth, the axial-ratio bandwidth, and the gain bandwidth are 27, 3.47 and 26%, respectively, for the left-hand circular polarization (LHCP) excitation, which provides a good improvement over the one with other single-point feeding techniques. This microstrip / L-probe feed can be extended to the design of a CP antenna array using sequential rotation. (C) 2000 John Wiley & Sons, Inc.