本研究的目的在探討適用於IEEE 802.16e-2005標準的移動式WiMAX多頻帶(2.4~6GHz)及雙頻段的小型天線之設計。 由於各個國家計畫分配給WiMAX的頻段不盡相同，惟基本上是以三個頻帶 2.5GHz、3.5GHz及5.8GHz為基礎，所以本研究設計了三種天線來滿足不同地區的系統需求。 吾人以槽洞(notch)天線結構出發，藉由線形偶極負載的引進，設計出三種符合WiMAX系統之天線；(1)雙頻WiMAX天線(2.5GHz及5.8GHz) ；(2)小型WiMAX天線(3.5GHz及5.8GHz)；(3)多頻帶WiMAX天線(2.4~6GHz)。 本研究並探討此小型WiMAX天線在設計過程中所遇到的困難與解決的辦法，及小型WiMAX天線線形偶極負載內緣各個邊緣位置對 S11 的敏感度。吾人特使用三明治式的FR4基板結構，以增加有效的介電係數，以使小型WiMAX天線尺寸縮小到只有20mm×20mm的大小。若不使用三明治式的FR4基板結構，只使用簡單的FR4基板，多頻帶WiMAX天線(2.4~6GHz)的尺寸也只有32mm×24mm的大小。 The goal of this thesis is to design a compact multi-band antenna for mobile WiMAX that conforms to the IEEE STD 802.16-2005. The released frequencies for mobile WiMAX in each country is not all the same but basically are located at 2.5GHz、3.5GHz or 5.8GHz. To satisfy those needs in different countries, we have designed three kinds of antennas. The antenna designs start with the strucute of notch antenna. By suitable loading the notch antenna with a wire-type dipole, we are able to accomplish three antenna propotypes that satisfy the frequency bands for mobile Wimax, which include: (1) double-band WiMAX antenna(2.5GHz and 5.8GHz), (2) compact WiMAX antenna (3.5GHz and 5.8GHz) and (3) multi-band WiMAX antenna(2.4~6GHz). This thesis also expounds the diffculties encountered during the designing process, and the ways for resolving the difficulties. The sensitivity of the inner edge for the linear dipole of the compact WiMAX antenna is also investigated. We have proposed the utilization of two layers of FR4 board to sandwich the notch radiator. By using the sandwich structure we are able to increase the effective dielectric constant such that the size of compact WiMAX antenna was decreased to just 20mm×20mm. On the other hand, even only one FR4 board is employed, the size of the multi-band WiMAX antenna is still small about 32mm×24mm.