低高度之數位電視天線設計

DESIGN OF LOW PROFILE ANTENNAS FOR DIGITAL TV RECEPTION

嚴和源(Ho-Yuan Yan)

指導教授 ： 吳宗霖 ； 黃啟芳

大同大學/電機資訊學院/通訊工程研究所/碩士(2004年)

摘要

本文分主要是設計一種適用於數位電視之接收天線，分為2個部分，且設計出2種不同應用的天線。所欲設計的指向性天線與 TTIC OFDM antenna project，所設計的天線頻段一致，所以沿用之前基本的天線結構，修改輻射體的角度，可旋轉天線的主極束，使每一個輻射單元，都對欲設計的方向加強輻射，而抵銷其他方向的輻射，使之成為具有指向性的天線。
緊接著研究垂直極化的傳輸線天線，為的達到小型化的目的，我們使用一低組抗的傳輸線加在天線末端，成為等校的電容負載，使得天線尺寸縮小，無須加入SMT電容即可縮小尺寸，再者，為了達到增加頻寬的效果，以相同結構的單一天線做結合，產生2共振路徑非常接近，使產生一個頻帶，以達到增加頻寬的效果，在數位電視的接收，也可達到很好的效能。

關鍵字

天線 ； 傳輸線

並列摘要

This thesis presents a design method for a receiving antenna of digital television which divided into two parts and designed two different applicable antennas. The bandwidth of directional antenna we want to design and the TTIC OFDM antenna project are the same, so we continue using the fundamental antenna structure. Revising the angle of radiator can go around the main beam of antenna and each radiation element strengthen radiation to our designed direction and counteract radiation from other directions, and then it will be a directional antenna.
Then studying vertically-polarized transmission line antenna in order to achieve the goal of miniaturization, we use a transmission line of low impedance and add it on the far end of antenna that becomes to equivalent capacitance load and narrowed the size of antenna. It’s not necessary to add SMT capacitance for narrowing size. In addition, in order to achieve the effect of increasing bandwidth, we use the antenna with the same structure to connect each other, it produce two resonant paths that are very close, then produce a bandwidth to achieve the effect. It also achieve the effect well in receiving of digital television.

並列關鍵字

antenna ； transmission line

參考文獻

[1] C. Eilers and G. Sgrignoli , ”Digital television transmission parameters-analysis and discussion”, IEEE Transactions on Broadcasting, vol.45 , PP.365-385, Dec. 1999.

[2] C. F. Huang, T. N. Chang and C.-Y. Hsu ,”Field evaluations in Taiwan of the DVB-T COFDM and ATSC 8-VSB digital TV systems”, EBU TECHNICAL REVIEW, July 2003.

[3] D. M. Pozar ,Microwave Engineering, John Wiley, New York, 1998.

[7] H. Nakano, R. Suzuki, and J. Yamauchi, “Low-pofile inverted-F antenna with parasitic elements on an infinite ground plane” Microwaves, Antennas and propagation, IEEE Proceedings, vol. 145, pp.321-325, Aug 1998.

[9] R. King, C. W. Harrison, Jr., and D. H. Denton, Jr., “Transmission-Line Missile Antenna,” IRE Transactions Antennas Propagation, vol. AP-8, pp.88-90, Jan. 1960.