Circularly polarized array antennas with electromagnetically coupled cross slot radiator

A circularly polarized cross slot array antennas fed by an open-ended microstrip line has been described. To obtain the broad impedance bandwidth, the cross slot is electromagnetically coupled to the feed line. The optimum parameters of a single element and an array with 15-elements are derived, and the beam tilting angle toward elevation direction is also presented. The calculated return loss and axial ratio of the 15-element array are -25 dB below and 1.4 dB below at DBS bands, respectively.