| 摘要: | 本三年期計畫擬以氮化鎵製程研製X 頻段小型脈波雷達發射機，研製之氮化鎵關鍵單石積體 電路晶片組成之小型固態雷達發射機應用於海事雷達時，可做為小型船隻在港灣、湖泊與複雜河道中 的航行輔助，以避免船舶碰撞。作為尋標器使用時，則具有主動雷達導引功能，具有搜索及追蹤能力。 計畫中包含兩組4 瓦特X 頻段功率放大器、切換器、次諧波升頻混頻器與本地功率震盪器之電路。 此直接升頻發射機模組將以高效率、高輸出功率、低相位雜訊與尺寸微小化等性能指標為主要設計目 標。預期成果為建立氮化鎵微波晶片電路設計相關技術及相關組裝量測技術。 計畫實行的第一年以1 瓦特與2 瓦特功率放大器、次諧波升頻混頻器與功率本地震盪器為設計目標；第二年則設計直接結合 與傳輸線轉換器兩組4 瓦特功率放大器與高功率、高速開關器；第三年為系統整合與組裝，將整合前 兩年完成之各個子電路，或利用電路構裝技術，藉以縮小核心晶片面積，以完成此雷達發射機系統晶 片模組。我們將考量系統電路之最佳化佈局以降低雜訊干擾、串接電路級間匹配、電路相鄰交互耦合 效應與高頻直流偏壓及旁路電容等最佳化處理。此外，由於GaN 電晶體操作於空乏型模式，因此需要 具有溫度補償和熱分流設計的偏壓順序電路以提供安全和可靠的測試。我們將組裝整個發射器模組， 包括單石積體電路晶片組、時序電路和散熱裝置治具，期使此雷達發射機系統達到高性能、高可靠性、 微形和低成本目標。 ;This three-year project is targeted to implement an X-band GaN solid-state miniature radar transmitter for marine radar and military target seeker applications. When used in marine radar, this transmitter can be used as a small vessel in harbor, lake and complex river navigation assistance to avoid collision of ships. When used as a target seeker, it has active radar guidance function, with search and tracking capabilities. This project will develops the key functional monolithic microwave integrated circuits (MMICs) which are two 4-W X-band power amplifiers, high speed and high power single-pole single thru switch, sub-harmonic mixer and local power oscillator (LO). The main performance metrics in this direct-up-conversion transmitter would be set as high efficiency, high output power, low phase noise and small form factor. The research team will develop the design, assembly and testing technologies of the GaN MMICs through this project. In the first year of this project, we will dedicate on the design of 1-W and 2-W power amplifiers, sub-harmonic up-conversion mixer and local oscillator. In the second year, our main goal will be the design of two 4-W power amplifiers by using direct-combining and transmission line transformer methodologies which are the most efficient for impedance transformation and power combining. Meanwhile, a high power and high speed SPST switch for this pulse radar transmitter will be implemented. In the third year, we will integrate the various well-developed sub-circuits for a complete radar transmitter system. We will consider the integration issues such as circuit placements, impedance matching, coupling effects, DC/RF bypass and interference between each stage. Moreover, since GaN transistors operate at depletion mode, a bias sequential circuit with temperature compensation and thermal shunt designs are required for safe and reliable testing. We will assemble whole radar transmitter module including MMICs, sequential circuits, and thermal fixture to achieve the goals of high performance, high efficient, high reliability, small form-factor and low cost. |
