用於諧波雷達傳感器之雙頻小型化環形天線設計

Design of Dual-Band Miniaturized Loop Antenna for Harmonic Radar Transponder

陳冠廷(Kuan-Ting Chen)

指導教授 ： 陳士元

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2020年)

https://doi.org/10.6342/NTU202100358

摘要

蜜蜂在生態系中扮演一個非常重要的角色，然而隨著蜂群崩潰症候群加劇，昆蟲學家開始關注與研究蜜蜂的習性，期望可以找出這個現象的成因。在電機領域，小型生物的野外搜索與追蹤一直是一項重要的研究議題，諧波雷達已經被廣泛的運用在這些研究之中。我們的目標是藉由諧波雷達搜索與追蹤野外的蜜蜂，協助昆蟲學家了解蜜蜂在野外的習性，以便解開蜜蜂消失之謎。在諧波雷達系統中，諧波傳感器特性的優劣將顯著地影響雷達的可偵測距離以及野外量測的結果。用於諧波傳感器的天線在設計上有諸多限制與挑戰。本論文提出一種可應用於諧波傳感器的雙頻小型化環形天線。此天線具有以下特性，第一是包含基板在內天線的尺寸小於5mm × 5mm，第二是天線可操作的頻率涵蓋基頻9.4 GHz (9.3-9.5 GHz)和二倍頻18.8 GHz，第三是在兩個頻段中其輻射場型是相似的且都是全向性的。與現有的差動式平面倒F天線(PIFA)相比，兩者同樣採用共平面的差動式架構。在9.4 GHz的頻率下，兩者具有相近的性能。但是在18.8 GHz的頻率下，本論文提出的雙頻小型化環形天線不僅具有更寬的頻寬，也具有更好的輻射效率。更寬的頻寬意味著此天線在其他的應用中具有更多的發展潛力，更好的輻射效率有助於提升諧波傳感器整體的性能。除此之外，此雙頻小型化環形天線可與共面帶線(Coplanar Strip, CPS)整合，此特性有助於更容易的量測此天線的表現以及被應用在更多的使用情境。

關鍵字

諧波雷達 ； 諧波傳感器 ； 雙頻天線 ； 小型化天線 ； 環形天線

並列摘要

Bees play a very important role in the ecosystem. However, as the colony collapse disorder (CCD) increased, entomologists began to pay attention to and study the habits of bees, hoping to find out the cause of this phenomenon. In the field of electrical engineering, the field searching and tracking of small creatures has always been an important research. Harmonic radar has been widely used in these studies. Our goal is to use harmonic radar to search and track bees in the wild, helping entomologists understand the habits of bees in the wild, in order to solve the mystery of bees disappearing. In a harmonic radar system, the characteristics of the harmonic transponder will significantly affect the detectable distance of the radar and the results of field measurement. There are many limitations and challenges when designing an antenna for a harmonic transponder. In this thesis, a dual-band miniaturized loop antenna that can be applied to a harmonic transponder has been proposed. This antenna has the following characteristics. The first is that the size of the antenna including the substrate is less than 5-mm × 5-mm. The second is that the operable bands of the antenna cover the fundamental frequency which is 9.4 GHz (9.3-9.5 GHz) and the double frequency which is 18.8 GHz. The third is that the radiation patterns in both bands are similar and omnidirectional. Compared with the existing differential planar inverted-F antenna (PIFA), both also use the coplanar differential structure. At the frequency of 9.4 GHz, the two have similar characteristics. But at the frequency of 18.8 GHz, the dual-band miniaturized loop antenna proposed in this thesis not only has a wider bandwidth, but also has better radiation efficiency. The wider bandwidth means that this antenna has more development potential in other applications, and the better radiation efficiency improves the overall performance of the harmonic transponder. In addition, the dual-band miniaturized loop antenna can be integrated with coplanar strip (CPS). This feature helps to measure the performance of the antenna more easily and makes this antenna can be used in more scenarios.

並列關鍵字

Harmonic radar ； Harmonic transponder ； dual-band antenna ； miniaturized antenna ； loop antenna

參考文獻

[1] Chensheng LU, Kenneth M. WARCHOL, Richard A. CALLAHAN, “In situ replication of honey bee colony collapse disorder,” in Bulletin of Insectology 65 (1): 99–106, 2012.

[2] Zuo-Min Tsai, Pei-Hung Jau, Nai-Chung Kuo, Jui-Chi Kao, Kun-You Lin, Fan-Ren Chang, En-Cheng Yang, and Huei Wang, “A high range resolution 9.4/18.8 GHz harmonic radar for bees searching,” 2012 IEEE/MTT-S International Microwave Symposium Digest, Montreal, QC, Canada, 2012, pp. 1–3.

[3] Zuo-Min Tsai, Pei-Hung Jau, Nai-Chung Kuo, Jui-Chi Kao, Kun-You Lin, Fan-Ren Chang, En-Cheng Yang, and Huei Wang, “A high-range-accuracy and high-sensitivity harmonic radar using pulse pseudorandom code for bee searching,” IEEE Transactions on Microwave Theory and Techniques, vol. 61, no. 1, pp. 666–675, Jan 2013.

[4] Miao-Lin Hsu, Tsung-Hsin Liu, Teng-Chieh Yang, Hsiang-Chieh Jhan, Huei Wang, Fan-Ren Chang, Kun-You Lin, En-Cheng Yang, Zuo-Min Tsai, “Bee Searching Radar With High Transmit–Receive Isolation Using Pulse Pseudorandom Code,” IEEE Transactions on Microwave Theory and Techniques, vol. 64, no. 12, December 2016.

[5] Yu-Ting Liu, Miao-Lin Hsu, Huei Wang and Zuo-Min Tsai “A Differential Miniature Transponder for 9.4/18.8 GHz Harmonic Bee Searching Radar with Low Gain Degradation from Bee’s Body,” 2016 IEEE MTT-S International Microwave Symposium (IMS), San Francisco, CA, USA, 2016, pp. 1–4.