- 期刊
採用兩級共源極串接之WiMAX功率放大器設計
WiMAX Power Amplifier Designs through Adopting Two-Stage Common-Source Cascade
摘要
本論文採用砷化鎵(GaAs)擬態高電子移動率電晶體(PHEMT)研製應用於全球互通微波存取(WiMAX)系統之2.6GHz功率放大器混成微波積體電路(HMIC)。因為WiMAX系統選擇頻率範圍為2.5至2.69GHz的美國多點微波分佈式系統(MMDS)頻帶，所以設計WiMAX功率放大器的中心頻率等於2.6GHz。電路架構採用兩級共源極串接設計，利用中間級(inter-stage)的阻抗匹配網路，在增益與輸出功率之間達到最佳的取捨(trade-off)，使功率放大器在適當輸出功率之下具有高增益的特性。第一級為小訊號放大器輸入級，使用單一顆電晶體為核心電路；第二級為功率放大器輸出級，為因應電晶體本身額定電流的限制，採用三顆電晶體並聯的形式實現。WiMAX功率放大器在頻率等於2.6GHz之重要參數量測結果，包括增益為25dB，輸出1dB壓縮點(OP(下標 1dB))等於18dBm，輸出三階交越點(OIP3)為29dBm以及功率附加效率(PAE)等於5%，所使用之供應電壓為3.6V，消耗電流等於282mA。
並列摘要
A 2.6 GHz power amplifier (PA) is designed and implemented in hybrid microwave integrated circuit (HMIC) using GaAs pseudomorphic high electron mobility transistor (PHEMT) for WiMAX applications. The center frequency of a WiMAX PA is designed at 2.6 GHz due to the selection of U.S. multi-point microwave distribution system (MMDS) band of frequency ranging from 2.5 to 2.69 GHz. The proposed design is based on two-stage common-source cascade configuration to achieve moderate output power and high gain using an inter-stage impedance-matching network. The first stage is a small-signal amplified input-stage with a single transistor to increase the gain. The second stage is a power amplified output-stage with three-parallel transistors to enhance the power. The crucial measured results of a WiMAX PA operated at 2.6 GHz show that a gain is equal to 25 dB, an output 1 dB compression point (OP(subscript 1dB)) is equal to 18 dBm, an output third-order intercept point (OIP3) is equal to 29 dBm, and a power added efficiency (PAE) is equal to 5 %. A supply voltage of 3.6 V is used and a current consumption is 282 mA.