In this thesis, a circularly polarized patch antenna fed by a microstrip-line is designed for the 60GHz (V-Band) communication system. In order to increase the bandwidth and polarization purity, a wide bandwidth microstrip-line fed circularly polarized patch array is proposed by combining the principle of sequential rotation technique and the 90° phase delay line for spatial rotation.
Based on the cavity model, the Helmholtz’s equation is solved to obtain the modes exist in the circular cavity resonator. From the mode analysis results, the electric current distribution patterns on the patch and the ground plane are computed. Because we need increase the bandwidth and the polarization purity, a microstrip-line fed circularly polarized patch array is proposed by employing the principle of sequential rotation technique. The simulated and measured return losses are presented for an 1x2 array with and without sequential rotation technique. Significant increase in the return loss bandwidth is found in the array with sequential rotation.
Because the proposed antenna is fed by the microstrip-line, in addition to the advantages of simple structure, lightweight, low profile, easy to combine with the circuit, and fabricate, this antenna is especially suitable for millimeter-wave application.