應用於船艦天線系統之天線性能的模擬與量測分析技術

近幾十年來，隨著電腦設備的進步，可以利用電腦程式來進行天線電磁場模擬的結構也越來越多，從最基本的微帶天線，到大型的金屬物件，例如:飛機，船艦…等。早期礙於電腦記憶體的價格昂貴，體積龐大，要運算如此大型的物件在當時可說是一項艱難的任務。時至今日，人們可以較輕易地取得足夠的記憶體來進行大型物件的電腦模擬，對於此類需要耗費大量時間與金錢的大型工程的設計來說有非常顯著的幫助。飛機、船艦等配備複雜無線通訊系統的大型金屬結構體，在設計時必須同時考慮天線在該機體上的運作能力是否能正常發揮。在如此狹窄的空間內安裝多支天線，除了輻射場型會因為金屬遮蔽物而變得不完整，同時也可能因為天線太過靠近而造成相互干擾，影響通訊品質。此類大型結構體，不論是在設計或是在製造階段，都必須花費龐大的資金與時間，若是在建造完成後再來量測與評估天線的性能是否受到影響，那麼當發現問題時將會變得難以修正。在這個情況下，縮尺模型理論便是一個解決此問題的好方法，利用縮尺模型，我們可以較輕易的發現出問題的結構，並且在設計階段就修正此問題，甚至可以利用縮尺模型來配置出最適當的結構。本篇論文主要的目標在使用電腦模擬軟體來模擬天線安裝在金屬船體上的不同位置時，會對場型造成什麼影響。之後，再利用以縮尺模型理論所製作的金屬船艦在無反射室中量測，並且比較模擬結果與實際量測之間的差異程度。

關鍵字

電磁場型模擬；縮尺理論

並列摘要

In last decades, there are more and more structures that can be simulated by the computer, including from the basic microstrip antennas, to the large metal structures, like ships or airplanes. In the early stage, it is a hard mission to calculate the structures with big size like this because of the price and volume of computer memory are both huge. Nowadays, people can easily get enough memory for the simulations of large structure, and this is a great help for the engineers of big structures design. Those large metal structures with complex wireless communication systems, like ships and airplanes, need to think about whether the antennas can work normally or not while designing. The narrow space is not only makes the patterns incomplete by metal shelters, but also may cause the interference of the antennas. It always costs a lot of time and money on this kind of large structures, no matter when designing or building. If we measure the performance of the antennas after it is done, the problems of the structures will be hard to correct. The target of this paper is using computer to simulate the performance of the antennas installed at the different position. Then we use the scaled down model to measure the patterns in the chamber, and compare the difference between measurement and simulation.

並列關鍵字

Electromagnetic field simulation ； scaled down theory

參考文獻

[1] Yoichi Nakagawa, Masahiro Mimura, KentaroMiyano, YoshioKoyanagi, and Kyohei Fujimoto,“Improved Method for Evaluating Antenna Performance in Moble Environment With Consideration of Polarization and Phase,” IEEE Transaction on Vehicular Technology, Vol. 52, No.5, September 2003.

[2] Young-Huang Chou, Shew- Lin, and Shyh-Jong Chung, “Analysis of a Grating Metal Structure With Broad Back-Scattering Field Pattern for Applications in Vehicle Collision Avoidance System,”IEEE Transactions on Vehicular Technology, Vol.51, No. 1, January 2002.

[3] Klaus-Werner Gurgel, “On the Performance of a Shipborne CurrentMapping HF Radar,” IEEE Journal of Oceanic Engineering, Vol. 25, No. 1, January 2000.

[4] G. Paul Francis and Donald H. Mark, “Amplitude and Phase Response of Freeboard-Mounted Ship Antennas,” IEEE Transactions on Antennas and Propagation, Vol. AP-21, No. 6, November 1973.

[5] P.J. Baldwin, A.G.P. Boswell, D.C. Brewster, and J.S. Allwright, “Iterative Calculation of Ship-borne HF Antenna Performance,” IEE Proceedings-H, Vol. 138, No. 2, April 1991.

國際替代計量

應用於船艦天線系統之天線性能的模擬與量測分析技術

未授權

主題瀏覽