本論文提出一個應用於第五代行動通訊系統之寬頻高線性度三級功率放大器。此功率放大器 使用磷化銦鎵/砷化鎵異質介面雙極電晶體製程製作並以3mm×3mm QFN封裝。其偏壓電路擁有溫 度補償架構能操作在-15℃ 到60℃ ， 使得功率放大器不容易受到溫度變化的影響。為了避免影響 功率放大器的性能，功率檢測器被放置於第三級功率級電晶體輸入端，且有較少電流損耗而可減 少效率的下降。使用5V供應電壓所量測到的功率增益和1dB增益壓縮點輸出功率分別為28dB和 30.5dBm。在頻率範圍5.5-5.9GHz與溫度25℃、使用頻率20MHz的64QAM正交頻分複用技術訊號 下， 功率放大器之誤差向量幅度接近3%， 所量測到的輸出功率為22.1-23dBm， 且在20dBm輸出 功率由功率檢測器量測到的電壓為0.595V。在頻率5.9GHz和溫度改變-15℃ 到60℃ 下，同誤差向 量幅度可維持輸出功率的誤差範圍在1.5dB內， 而同偵測電壓能維持輸出功率的誤差範圍在1dB 內。

This paper presents a broadband high-linearity three-stage power amplifier for 5G mobile communication systems. The power amplifier is fabricated using InGaP/GaAs HBT technology and packaged in a 3mm×3mm QFN. The bias circuits have temperature compensation within the operating temperature range from -15℃ to 60℃ , hence the power amplifier is not susceptible to temperature change. The power detector is placed at input terminal of the third power stage transistor in order to avoid affecting the performance of the power amplifier and has less current consumption to get less efficiency degradation. The measured power gain and P1dB are respectively 28dB and 30.5dBm at 5V supply. With a 20MHz 64QAM Orthogonal Frequency Division Multiplexing(OFDM) signal at the frequency of 5.5-5.9GHz and temperature of 25℃ , the power amplifier achieves 3% EVM at 22.1-23dBm output power and the output voltage of the power detector is 0.595V at 20dBm output power. When the temperature changes from -15℃ to 60℃ at the frequency of 5.9GHz, the tolerance of the output power is less than 1.5dB with the same EVM and the tolerance of the output power is less than 1dB for the same detector voltage.