室內數位電視廣播智慧型天線設計

隨著社會的發展和現代科學技術的進步，家庭生活的數位化，提升人們生活的便利性。DVB-T是歐規數位電視的規格，主要採用了編碼正交分頻多工（coded orthogonal frequency division multiplexing）的技術方式克服無線傳播通道先天性的限制，其具有行動接收、抗回波及抗多路徑干擾等優點。然而，其缺點在於處於高速移動下會造成收訊不良的問題，且訊號也會受建築物高度、地形等因素影響。另外，室內與室外在接收訊號的部份，室內的接收訊號會明顯比室外還差。主要是因為室外的數位電視接收天線與數位電視廣播發射台屬於直視線（line of sight）的傳輸，而室內的屬於非直視線（non-line of sight）傳輸。　　本論文為了提昇室內數位電視接收品質，其設計在台灣數位電視廣播頻段（530 MHz∼596 MHz）之1×4波束切換式陣列天線系統，結構包含巴特勒矩陣耦合器、相移器、微控制器和天線構成的波束切換式電路。並且將原尺寸傳輸線模型透過LC電路理論縮小化，成為LC電路之1×4波束切換式天線系統。陣列天線的部份分別以四支天線單元相距半波長的距離連接至波束切換式電路之前端，最後合成的訊號再饋入至數位電視接收模組。此縮小化電路未來可整合在平板電腦和筆記型電腦等3C產品上，以增加室內數位電視收訊能力。

關鍵字

波束切換式陣列天線；智慧型天線；巴特勒矩陣； LC電路

並列摘要

Along with the development of the society, scientific progress and digital life, people are now living in a more convenient world. DVB-T is the European digital TV standard that uses COFDM (coded orthogonal frequency division multiplexing) technology to overcome the limitations of congenital radio propagation channel. Being in a fast moving or indoor environment, COFDM technology could result in poor reception; the signal would also be affected by the heights of a building, topography and more. In addition, the interior of the received signal would not work as well as outdoor because the signal is mainly based on the line of sight transmission while the interior part is non-line of sight transmission. 　　In this thesis, a beam switching smart antenna array system worked at 530 MHz ~ 596 MHz frequency band was implemented. The proposed spatial filtering system contains Butler matrix, phase shifter, microcontroller and antenna array. It showed that the beam switching system could be miniaturized by LC circuit. Besides, the implemented system was validated in several typical indoor environments by connected in to a digital television receiver module. This miniaturized circuit could be integrated with tablet personal computer, laptop, or commercial product to increase reception capability of indoor digital television.

並列關鍵字

Antenna Array ； Bulter Matrix ； Smart Antenna ； LC circuit

參考文獻

[1] 劉家原，應用於WiMAX之波束切換系統實現，碩士論文，國立台北科技大學電

[5] 陳鵬書，應用於數位電視接收機之螺旋多模態諧振微型化天線，國立台北科技　　　大學電腦與通訊所，台北，2009。

[6] Simon R. Saunders, Antenna and Propagation For Wireless 　　　Communication Systems, New Jersey: John 　　　　　　　　　　　　Wiley&Sons,Inc,2007

[8] Erio Gandini and Ronan Sauleau, “A Lumped-Element Unit 　　　Cell for Beam-Forming Networks and Its Application to a 　　　Miniaturized Butler Matrix,” Microwave Theory and 　　　　　　Techniques, IEEE Transactions on, Volume:61 , Issue: 4 　　　, April 2013, pp.1477-1487

[9] De-Jing Ma, Hong-Li Peng, Wen-Yan Yin, and Jun-Fa Mao, 　　"The realization of high isolation and wide band 4×4 　　　　microstrip Butler matrix," Microwave Technology & 　　　　　　Computational Electromagnetics, Beijing, 2009, pp.88-92.

國際替代計量

室內數位電視廣播智慧型天線設計

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