| Summary: | 碩士 === 國立臺灣大學 === 電信工程學研究所 === 103 === In this thesis, a dual-feed dual circularly polarized oversize antenna is proposed for 61 GHz ISM band application. The term “oversize” means that comparing to conventional patch antenna operated at the fundamental mode, the proposed antenna is enlarged due to implemented at the higher-order mode. In millimeter-wave band, the dimension of the antenna is close to that of the microstrip feeding line which causes the feeding difficulties. This problem can be solved by the proposed antenna without any complicated matching networks. Moreover, since the dimension of the antenna is enlarged, the manufacturing tolerances can be increased.
The proposed circularly polarized rectangular patch antenna with is achieved by truncating its two corners. By exploiting two vertically placed microstrip feeding lines, the proposed antenna has orthogonal circular polarizations for polarization diversity applications. Owing to its enlarged size, the oversize antenna has higher gain than that of the conventional one without using array design. In addition, this design is fed by two inset microstrip lines that can enhance the isolation between the two ports. The proposed design has a simple and single-layer structure.
This design is fabricated on the RO4003 simulated and verified at the 5.8 GHz band. The simulated and measured results are in good agreement. Up to 15 dB isolation are achieved. The simulation of 61 GHz version is provided for future experimental verification.
|
|---|
