利用改良式威爾金森功率結合器提升脈衝調變極化發射機之效率

Abstract

本論文的主旨是提出一個具有提升功率放大器之效率的改良式威金森功率結合器。將兩路兩相的功率放大器組織成雙相位脈衝調變極化發射機並利用改良式威金森功率結合器對輸出進行整合，藉此有脈衝產生的頻帶外諧波項次可以被抑制。再者，改良式威金森功率結合器具有可以回收損失在雙相位脈衝調變極化發射機上的發散功率。利用這個被提出的架構，在使用中心頻率為836.5-MHz 與10-MHz 脈衝調變信號的情況下，整體發射機系統的效率達到43%同時系統的輸出功率為24.2 dBm 。在使用中心頻率為836.5-MHz 與脈衝調變LTE手機信號的情況下，整體發射機系統的效率達到41.2%同時系統的輸出功率為23.5 dBm 。本論文主要於驗證改良式威金森功率結合器對功率放大器的回收效能。

This dissertation presents a method for improving the efficiency of a power amplifier (PA) using a modified Wilkinson power combiner (WPC). By configuring the PA into a dual-phase pulse modulated polar transmitter (PMPT) and combing with a modified Wilkinson power combiner, the out-of-band harmonics created by the pulses can be reduced. Moreover, the modified Wilkinson power combiner recycles the power when the input signals of the dual-phase PMPT are not turned on concurrently. Using the proposed architecture, the prototype system transmitter system achieved a 43% drain efficiency at an output channel power of 24.2 dBm using a 10-MHz dual-phase pulsewidth modulation (PWM) signal with carrier frequency at 836.5 MHz. Using a 10-MHz bandwidth long-term evolution (LTE) PWM signal at 836.5 MHz the system achieved a drain efficiency of 41.2% with a channel output power of 23.5dBm while passing the spectral requirements of the LTE standard for mobile handset devices.