本研究論文主要是針對無線區域網路(WLAN)與全球互通微波存取(WiMAX)之天線進行研究與設計，以滿足無線網路系統上之應用。論文所提出天線架構包含兩個晶片電感、兩個細長的金屬片與另一個U型的寄生元件。對低頻2450MHz的頻段來說，嵌入一個電感值5.6nH的晶片電感可以使得輻射元件的長度只有21.2mm(在2450MHz共振時，大約為0.17個波長長度)，而對中頻3500MHz的頻段來說，嵌入一個電感值2.7nH的晶片電感，讓輻射元件的長度只有17.3mm(在3500MHz共振時，大約為0.2個波長長度)，2450MHz與3500MHz皆是用印刷式倒F型天線設計。最後利用寄生的方式設計二分之一波長共振5500MHz頻帶的天線(在5500MHz共振時，大約為0.45個波長長度)。整體天線使用雙層FR4的設計方式，將2450MHz的輻射元件放置於雙層FR4的上層位置，而3500MHz的輻射元件放置於雙層FR4的下層位置，最後的5500MHz寄生元件則是放在雙層FR4之間，此種作法可以使天線不須要再佔額外的面積來放置寄生元件的位置。整體三頻天線的設計可以應用於2450/3500/5500MHz的頻段，且空間所佔據的體積只有102.4mm3，平面所佔據的面積只有64mm2。The goal of the thesis is to design compact antennas for WLAN (Wireless Local Area Network) and WiMAX (Worldwide Interoperability for Microwave Access). The proposed antenna structure is composed of two chip inductors, two thin radiating strip and an U-shaped parasitic element. For the low band of 2450MHz, embedding a chip inductance of 5.6nH in the radiating strip can result in the antenna length of 21.2mm (about 0.17 wavelength at 2450MHz). For the first high band of 3500MHz, embedding a chip inductance 2.7nH in the radiating strip can lead to the antenna length of 17.3mm (about 0.2 wavelength at 3500MHz). Finally, a parasitic element resonating at one-half wavelength in the second high band at 5500MHz (about 0.45 wavelength at 5500MHz) is used to obtain the third frequency band for the antenna. In the antenna design the FR4 printed circuit board is used. The 2450MHz radiating components are placed in the top layer of the double-layer FR4, and the 3500MHz radiation components are placed in the bottom layer of double-layer FR4. Finally, the 5500MHz parasitic element is placed in the middle of the double-layer FR4. Using the proposed design scheme can solve the problem that the extra space is often required for deploying the parasitic elements. The proposed tri-band antenna design can be used in the three operating bands of 2450/3500/5500MHz, and the overall antenna volume and area are about 102.4 mm3 and 64 mm2, respectively.
