寬頻多層空腔共振天線之研製

Design and Implementation of Broadband Cavity Resonant Antennas Using Multi-layer Structures

陳碩浩(Shuo-Hao Chen)

指導教授 ： 林怡成

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.10103

摘要

本篇論文提出兩種部分反射面之設計。第一種具高反射量與正相位梯度之線性極化部分反射面，並製作於印刷電路板上。而後形成一空腔共振天線，並加上金屬壁面後，再針對其尺寸作分析。最後，使用一背向饋入之基板集成波導激發此空腔。在操作頻率12.9GHz時，正向輻射(broadside)方向增益有15dB，且其3dB方向增益頻寬百分比有8.8%。第二種部分反射面則是利用兩片印刷電路板構成，並進一步組裝成雙空腔共振天線，透過調整第二片部分反射面的反射量可形成寬頻方向增益的設計。接著，利用一印刷電路板所組成的背覆空腔式孔徑天線來激發空腔設計，此設計可透過抽換一片印刷電路板且無須更動其他參數設計下，達成線性或圓形極化輻射。線性極化具有17.5dB方向增益與13%的方向增益頻寬百分比；圓形極化具有18.4dB方向增益與11.6%的方向增益頻寬百分比以及6.7%的3dB軸長比(axial ratio)頻寬百分。

關鍵字

背覆空腔式孔徑天線 ； 空腔共振天線 ； 相位正梯度 ； 部分反射面 ； 基板集成波導

並列摘要

This thesis presents two types of partially reflective surface (PRS). The first one is a PRS of high reflectivity and positive phase gradient fabricated on printed circuit board (PCB), where a cavity resonant antenna is built with such a PRS. After adding metallic walls to the cavity edges, we analyze the cavity dimension for optimal aperture efficiency. Then, we use a backed substrate integrated waveguide (SIW) to excite the cavity. A broadside gain of 15dB is obtained at 12.9GHz and the corresponding 3dB fractional gain flatness bandwidth is 8.8%. The second PRS design is composed of two PCBs, and we further use it to form a double cavity resonant antenna. Through adjusting the reflectivity of PRS2, the broadside radiation could be wideband. Next, we use a cavity-backed aperture antenna which is composed of multi-PCB to excite the resonant cavity, and we can switch a piece of PCB of this antenna to get linear polarized or circular polarized radiation. In the linearly polarized case, a broadside gain is 17.5dB and the corresponding 3dB gain flatness bandwidth is 13%. In the circularly polarized case, a broadside gain is 18.4dB and the corresponding 3dB gain flatness bandwidth is 11.7% and 3dB axial ratio bandwidth is 6.7%.

並列關鍵字

Cavity-backed aperture antenna ； cavity resonant antenna ； positive phase gradient ； partially reflective surface ； substrate integrated waveguide

參考文獻

[1] G. V. Trentini, “Partially reflective sheet arrays,” IRE Trans. Antennas Propag., vol. 4, no. 4, pp. 666–671, Oct. 1956.

[2] D. R. Jackson and N. G. Alexopoulos, “Gain enhancement methods for printed circuit antennas,” IEEE Trans. Antennas Propag., vol. 33, no. 9, pp. 976–987, Sep. 1985.

[3] A. Foroozesh and L. Shafai, “Investigation into the effects of reflection phase characteristics of highly-reflective superstrates on resonant cavity antennas,” IEEE Trans. Antennas Propag., vol. 58, no. 10, pp. 3392–3396, Oct. 2010.

[4] A. Foroozesh and L. Shafai, “On the characteristics of the highly directive resonant cavity antenna having metal strip grating superstrate,” IEEE Trans. Antennas Propag., vol. 60, no. 1, pp. 78–91, Jan. 2012.

[5] N. Guerin, S. Enoch, G. Tayeb, P. Sabouroux, P. Vincent, and H. Legay, “A metallic Fabry-Perot directive antenna,” IEEE Trans. Antennas Propag., vol. 54, no. 1, pp. 220–224, Jan. 2006.