In the thesis, we designed a metamaterial radome to increase the antenna gain. Owing to the need of high-directivity radiation in fix-point communications, antenna array and reflective antenna had been used to increase the directivity of antenna traditionally. Complicated feed and huge antenna size are the disadvantages of these techniques. We proposed a simpler metamaterial radome to increase the antenna gain.
We find the subwavelength-hole structure formed by four Jerusalem cross structures can collimate electromagnetic wave originally spreading out from the holes. With the same size, multiple subwavelength holes in metamaterial radome can further enhance the antenna gain. We showed that metamaterial radome with 9 subwavelength holes can improve the gain by about 3.5 dB. In addition, we applied the concept of Fabry-Perot Cavity (FPC) to find the suitable distance between the radome and the antenna. When the resulting electromagnetic waves are in-phase, the radome can increase the antenna gain effectively.
Recently, high-directivity radiation in fix-point communications is required and in the meantime multi-mode communication systems have become more and more popular. For practical purposes, we designed a coplanar dual-band metamaterial radome to be operated at 2.5 GHz and 3.5 GHz for WiMAX. This structure allows adjustment of its characteristics independently at each band. This coplanar dual-band radome can enhance the antenna gain by about 1.74 dB and 2.08 dB at 2.5 GHz and 3.5 GHz, respectively.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0728110-115026 |
| Date | 28 July 2010 |
| Creators | Chen, Kai-shyung |
| Contributors | Chih-Wen Kuo, Ken-Huang Lin, Sung-Lin Chen, Lih-Tyng Hwang, Hsin-Lung Su |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0728110-115026 |
| Rights | not_available, Copyright information available at source archive |
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