一2.5到2.7 GHz應用於第五代行動通訊的小型基地台功率放大器透過砷化鎵製程來實現，為 了滿足第五代行動通訊的高線性需求，建議的偏壓電路必須要同時補償增益誤差和相位誤差，透 過適當的設計，功率級電晶體達到34 dBm和53.9 %的高效率。此外，為了達到大於30 dB的增益， 我們設計兩級驅動級電晶體，搭配功率級電晶體，整合實現一功率放大器晶片，當用頻寬20MHz 的標準第五代行動通訊訊號饋入功率放大器時， 並在相鄰通道功率比(Adjacent Channel Power Ratio；ACPR)為-47 dBc下，其線性輸出功率和效率(Power Added Efficiency；PAE)分別為25dBm 及17%。最後，為了滿足第五代行動通訊長距離傳輸的需求，使用兩個功率放大器搭配90度耦合 器進行功率合併， 來達到線性功率27dBm及效率大於15%之特性。

A broadband RFIC power amplifier covering 2.5 to 2.7 GHz band and targeting 5G small -cell applications has been implemented through GaAs HBT technology. To meet high linearity requirements of 5G small-cell applications, the proposed linearization bias circuit has the characteristics of gain and phase compensations for the proposed power amplifier. The power stage achieves 1-dB compression point (P1dB) of 34 dBm and the power -added efficiency (PAE) at P1dB of 53.9%. In addition, to achieve greater than 30 dB small signal gain of the power amplifier, two driver stages are implemented and incorporated with the proposed power stage. When the proposed power amplifier is tested with the standard 5G 20 MHz signal, the output power and PAE with -47 dBc adjacent channel leakage ratio (ACLR) are 25 dBm and 17 %, respectively. Finally, to satisfy 5G long distance transmission requirements, combination with the output power of two proposed power amplifiers accomplishes linear output power of 27 dBm and superior than PAE of 15% by utilizing quadrature hybrid couplers.