- 學位論文
利用功率結合電路之寬頻功率放大器
Broadband Power Amplifier Using Power Combining Circuit
摘要
本論文採用互補式金屬氧化電晶體0.18μm(CMOS 0.18μm)製程之寬頻功率放大器，使用疊接(cascode)結構，以增加電路的操作崩潰電壓；利用並聯式功率結合器，將兩路的功率放大器做功率結合，以提高輸出功率，而透過具有寬頻操作特性的變壓器匹配網路，使功率放大器可以操作在寬頻帶。汲極端電壓為4.1伏特的狀態下，此功率放大器在1.65~2.45GHZ時的1dB壓縮點輸出功率(1 dB compression point output power；OP1dB)為26~27.6dBm，功率附加效率(Power Added Efficiency；PAE)為15~22%，而增益為12.4dB~32dB。在線性功率方面，以峰均功率比(Peak-to-Average Power Ratio；PAPR)為2.7dB的寬頻分碼多工(Wideband Code Division Multiple Access；WCDMA)調變訊號作測試，在中心頻率平移5MHz下，工作頻率1.65~1.95GHz通過臨界通道洩漏比(Adjacent Channel Leakage Ratio；ACLR)小於-36dBc規範的輸出功率皆在22.8dBm之上，而工作頻率1.65~2.45GHz通過ACLR小於-33dBc規範的輸出功率在23.3dBm以上。 無線行動通訊系統未來面臨到的是更多頻段的應用，故寬頻功率放大器可以節省以往積體化多顆窄頻PA所佔據的晶片面積，以及減少射頻發射機前端電路的設計複雜度，使射頻發射機整合的成功率增加；擁有高功率輸出的系統，意味著此系統能夠涵蓋更廣的應用範圍；而擁有高的線性輸出，則是因應未來調變訊號的PAPR及頻寬日益增加的趨勢。
並列摘要
This thesis proposed broadband power amplifier using Complementary Metal Oxide Semiconductor 0.18μm process. The cascade architecture was used to increase operating breakdown voltage and parallel power combiner united two power stages to increase output power. According broadband characteristic of transformer matching network, the power amplifier could work in broadband. When this power amplifier’s drain voltage was 4.1 Volt, the measured output 1-dB compressed power, power added efficiency and power gain in 1.65~2.45GHz were 26~27.6dBm, 15~22% and 12.4~32dB. At the mention of linear power, a Wideband Code Division Multiple Access modulated signal with 2.7 dB Peak-to-Average Power Ratio (PAPR) was used to test. Under the frequency offset is 5 MHz from center frequency, the power amplifier’s output power in 1.65~1.95GHz passing the Adjacent Channel Leakage Ratio(ACLR) less than -36dBc was more than 22.8dBm, and in 1.65~2.45GHz passing the ACLR less than -33dBc was more than 23.3dBm. Wireless mobile communication system is faced with multi-band application, so broadband power amplifier can save the size occupied by integrating many narrow band power amplifiers in a chip before, decrease the design complexity of ratio frequency transmitter from end circuit therefore. A system with high output power means this system application range is wider; with high linear output power is to respond ever-growing modulated signal PAPR.