在本文中將探討應用於個人電腦的27MHz無線滑鼠天線傳輸效能的改善及阻抗匹配的設計與應用。
由於工作頻率在27MHz的關係，理論上需要較長的天線才能得到比較好的傳輸效率，但是由於機構本身限制了天線的長度與範圍，故應用了螺旋型天線，天線串聯電容，天線陣列，延長型天線等實驗來改善傳輸效率，而由實驗中發現，僅天線串聯電容及天線陣列能夠增加實際傳輸的距離，其增加率分別為32%及64%。
再來則是阻抗匹配的討論與設計，由於廻圈天線的幅射阻抗極小，約只有0.00004歐姆，故要讓功率傳到天線上再幅射出去，是一定要考慮阻抗匹配，文中會先對原始的電路作模擬，然後再經由L型多階電路設計達到良好的阻抗匹配，在原始電路的Return Lose約為-5dB，經過設計的電路為-27dB。

The main subject of this paper is to discuss the improvement of the antenna efficiency and the design concept of impedance matching operating on a 27MHz wireless mouse.
First of all, the improvement of antenna efficiency. Theoretically longer antenna is needed in order to get better transmission efficiency when operating in 27MHz.
However, the length and available range of antenna is often limited by the design of mechanism. As a result, some experimental replacements of longer antenna such as “Helical Antenna”, “Capacitor Series”, “Antenna Array”, “Extended Antenna” are used to improve the efficiency of transmitting.
According to the result of the experiment, the transmitting distance can only be increased by the “Capacitor Series” and the “Antenna array”, the increase rate is 32% and 64% respectively.
Secondly, the design of impedance matching, in order to radiate the power from the antenna, impedance matching must be considered heavily due to the extremely small radiation resistance of the loop antenna—about 0.0004Ω.
In the first step, the initial circuit of the mouse is simulated. Then by using L-type circuit, better impedance matching can be reached. The statistics of the return loss is improved from -5db to -27db.

[1] 黃胤年，電波傳播與天線，五南圖書有限公司，2003
[2] Preliminary spec 1.0, ”MA60H22 RF Optical Mouse Controller ,” MosArt Semicondutor corp., 2002.
[3] Specification 1.8, ”27MHz RF Keyboard and Mouse Receiver Controller USB or PS/2 Interface ,” MosArt Semicondutor corp., 2005.
[4] 賈志靜，高頻電路分析與設計修訂版，全華科技圖書有限公司，2001
[5] J. D. Kraus, R. J. Marhefka ”Antennas For All Application” McGraw-Hill Book Company, 2002, p 207.
[6] 鈴木茂夫，高頻技術入門，建興文化圖書有限公司，2007
[7] Pey-Ling Teng, Ching-yuan Chiu, and King-Lu Wong, “Intenal planar monopole antenna for GSM/DCS/PCS folder-type mobile phones,” Microwave Opt. Technol.Lett.,vol.39,pp.106-108,2003.
[8] H. Morishita, Y. Kim, and K. Fujimoto, “Design concept of antennas for small mobile terminals and the future perspective,” IEEE Antennas Propag. Mag., vol. 44, no. 5, pp. 30-43, Oct. 2002.
[9] Application note nAN400-03, “Small loop antennas,” NordicVLSI ASA, Feb. 2000.
[10] Bob Atkins, ”Helical Antenna Design” , KA1GT , Ch9.
[11] Andrei Grebennikov, “RF and Microwave Power Amplifier Design,” McGraw-Hill Book Company, pp. 109-131, 2002.