利用封包消除與重建降低諧波雜訊

Abstract

近年來行動通訊裝置越來越普及，使得提升射頻發射機效率成為重要的議題，其中功率放大器是影響的主因之一，相較於傳統的固定偏壓功率放大器，動態偏壓功率放大器能有更高的效率，而動態偏壓需要使用封包放大器，動態偏壓放大器的發射機有三種架構，分別為封包追蹤、封包消除與重建以及混合封包消除與重建，本論文設計之封包放大器將應用封包消除與重建發射機當中。 本論文設計的封包放大器採用封包消除與重建的方式以及modified EER，將封包訊號分為封包振幅和相位，高頻訊號由線性放大器處理，低頻訊號則是由切換式放大器，並使用EER的技術將脈衝調變產生的諧波雜訊降低。

With the blooming of wireless communication, mobile communication devices have become quite significant in recent years, so enhancing the efficiency of radio frequency transmitter becomes an important issue. The power amplifier (PA) is one of the main factors affecting the efficiency of the transmitter. The PA with dynamic bias voltage has higher efficiency comparing to the PA with fixed bias voltage. There are three structures of transmitter using the PA with dynamic bias voltage, including envelope tracking (ET), envelope elimination and restoration (EER), and hybrid envelope elimination and restoration (Hybrid EER). The envelope amplifier designed in the thesis will be used in EER. In this thesis, EER and modified EER are used. EER means to separate the envelope signal into amplitude information and phase information. The high frequency signal is processed by the linear amplifier, and the low frequency signal is processed by the switching amplifier. Furthermore, EER is used to reduce the out-of-band spurs caused by pulse width modulation.