應用於Ka-頻段衛星通訊之雙頻雙極化微帶天線

Abstract

Antennas are an essential part in a communication system as they control a spatial and temporal coverage of the signal. Circularly polarized (CP) patch antennas have a wide range of applications because of their low profile, low cost, and easy fabrication. In this thesis, two antenna structures are presented for the Ka-band communications. Initially, two square patch antennas configured with side by side are designed at two different frequencies. Each patch element is excited by using two separate probe feeds for the right- and left-hand circular polarization operations. The cavity wall is used to improve the isolation of the design. For the second approach, dual stacked patch antenna is presented for the enhanced impedance bandwidth with reduced antenna area. Both designs used a 90-degree hybrid coupler to achieve LHCP & RHCP.