靜態功率48.2mW, 4~11GHz 子E類功率放大器在輸出功率22dBm時有PAE為35.9%

Abstract

隨著科技演進，隨身行動通訊系統相較於過去十年有了飛躍性的進展，更輕、更薄、更持久的手機、平板以及筆記型電腦推陳出新。然而，在無線通訊系統中，功率消耗一直是設計者最大的考量之一。而身為通訊系統的一部分，功率放大器通常佔據了功率損耗最大的部分。也因此，相較於傳統的A類、B類及AB類線性放大器，越來越多的非線性功率放大器開始出現在現代人的眼前。相較於傳統的AB類功率放大器只有50~78.5%的轉換效率，E類功率放大器透過切換式操作，可達到理論上100%的直流到交流功率轉換，將可以大大增加無線通訊裝置的使用時間，提升無線通訊裝置的使用壽命。然而，切換式功率放大器(Switch)在時間軸上的不連續性，讓設計者必須處理複雜的非線性微分方程式，也使該類設計令人望之卻步。 在這篇論文中，我們一開始討論傳統的E類功率放大器，從數學模型進一步推導出其他不同於傳統E類的功率放大器操作模式，論文中稱之為子E類功率放大器。選定特定製程參數的元件，以及對電路各部分的元件非理想電阻進行假設，進一步計算出子E類功率放大器的最佳操作區間。在結尾的部分，我們會提出子E類放大器的設計流程，包括元件的選定及輸出級的匹配電路，透過國家晶片中心(CIC)所提供的TSMC-TN90RF製程完成晶片下線後，提出量測結果驗證我們所提出的理論，並比較模擬及量測結果，完成論文。

With the advancement of the technology, the mobile devices have the dramatically progress in recent ten years. Lighter, thinner and low power cell phones、pads and laptops hit the market. However, as one of the main consideration in the communication system, power dissipation in power amplifiers take presence into the designer’s eyes. Take comparison to the traditional Class A, B and AB power amplifiers, who have DC to RF power transfer ratio between 50 to 78.5%, switch-mode power amplifier in Class E has potentially 100% efficiency to convert DC power to the RF output, which could highly enhance the operation time of our devices. However, the non-homogeneous second-order differential equation from the discontinuity switching operation builds the difficulty in front of designers to reach it closer. In this paper, we would discuss about the traditional Class E Power Amplifier from the mathematical model and focus on the previous boundary conditions. From these initial conditions of the traditional ones, we could get some intuition of the operation method from its physical meaning. Then, we would like to reduce these limits form the previous version of Class E Power Amplifier to display the Sub-Class E operation. By building reliable loss models for deeply reach the truth; we would prove the optimum design version of the new proposed schematic. Using TSMC TN90RF process to physically build up the circuit, we could verify our new proposed structure and compare results from simulation and measurement to finish this paper.