具高能量效率之射頻發射器

Abstract

在無線傳輸系統中，低功耗以及高效能是主要的設計考量。本論文提出一可達到低功耗及高效能之調變架構。在傳統的以混波器為基底之發射機系統中，數位類比轉換器, 濾波器以及混波器會消耗大量的電流，並且會帶來許多類比電路的非理想效應。本調變系統的核心電路為一相位選擇器，用來取代上述電路以達到低功耗的效能，並且基於開路調變的特性，本系統可達到高傳輸效率的表現。 第一個作品為應用於二十四億赫茲之無線射頻發射器，使用相位切換之架構支援OQPSK, HS-OQPSK, 8-PSK,以及16-QAM之調變。本傳輸器實現於90奈米製程。量測結果顯示本傳輸系統在 -3 dBm的輸出功率下傳輸速度最高可達105 Mbps。其EVM值小於10.6 %，而在操作電壓為1.2伏特下消耗功耗為9.25毫瓦。第二個作品為第一個作品之改進版本，分別對嵌入式FIR濾波器所產生的數位突波以及16-QAM調變下的準確度做改進。 第三個作品為一應用於生醫系統之無線射頻發射器，使用邊緣合併以及相位切換之技術達到低功耗以及高傳輸速率。本晶片實現於0.18微米互補式金氧半製程，其效能於0.8伏特供應電壓下消耗330微瓦並達到15 Mps的傳輸資料量。

In the wireless communication system, low power and high efficiency are major concern, and this thesis proposes a modulation architecture which can achieve low power and high data rate requirement. For a traditional mixer-based transmitter architecture, the DACs, filters, and mixers consume large power under high data rate and induce many non-idealities of analog circuits. The core of the proposed modulation architecture is a phase selector, which replaces these analog circuits and achieves low-power performance. Furthermore, the open loop characteristic facilitates the high data rate operation. The first work is a 2.4-GHz wireless transmitter, which adopts phase selector technique and can support OQPSK, HS-OQPSK, 8-PSK, and 16-QAM modulation. This chip is fabricated in a 90-nm CMOS process. The experimental results show that the transmitter delivers 105-Mbps maximum data rate under -3 dBm output power. The EVM is lower than 10.6 %, and the total power consumption of the transmitter is 9.25 mW under a 1.2-V supply. The second work is improved from the first work. The improvement includes the FIR digital spur reducing and enhancing accuracy in 16-QAM modulation. The third work is for bio-medical wireless application. This work can achieve low power and high data rate by using edge combining and phase selector technique. This chip is fabricated in a 0.18-um CMOS process. The transmitter consumes 300 uW at 15 Mbps from a 0.8-V supply.