臺灣博碩士論文加值系統

　　傳統線性發射機具有高線性度但效率低的特性，當輸入為具有高峰值對平均功率比(Peak-to-Average Power Ratio, PAPR)的非固定波包調制訊號時，線性發射機需要採用功率倒退的方式以維持訊號品質，但同時也將導致功率轉換效率的下降。有別於線性發射機架構，波包追隨式發射機的功率放大器供應電源電壓與調制訊號波包之間呈現正比關係以降低功率放大器的直流功率消耗，進而提升轉換效率。本論文實現了一個頻率為2.4 GHz之波包追隨式發射機，主要電路包含線性AB類的射頻功率放大器、波包放大器以及基頻數位處理器。在波包路徑上，傳統的波包消除與回復架構是利用波包檢測器取得調變訊號的波包之後，再經由波包放大器將波包放大。本論文的波包產生方式與一般極座標發射機架構相同，使用數位訊號處理的方式將 訊號經由CORDIC轉換來產生波包。波包放大器是由Buck切換式直流對直流轉換器、比較器以及寬頻線性操作放大器所組成的，亦稱為分頻波包放大器，分頻的方法可以減緩傳統架構對直流轉換器切換速度的要求。

The conventional linear transmitter possesses the characteristic of trading the efficiency for linearity. When a non-constant envelope modulated signal with a high peak-to-average power ratio (PARR) goes into the transmitter, the transmitter has to request the power amplifier (PA) of power backing-off to keep the signal quality from degradation. In this scenario, the power back-off is going to decrease the PA efficiency for the linearity. In contrast to the linear transmitter, the envelope following transmitter is supplied by a voltage source that has a regulated output voltage proportional to the amplitude of the input RF signal, and consequently increases the conversion efficiency while reduces the dc power consumption of the PA. This work has implemented a 2.4 GHz envelope following transmitter built by a linear class-AB PA, an envelope amplifier, and a baseband digital processor. The split-band technique of the envelope amplifier was applied in this work to avoid the dc-to-dc converter from high-speed switching, and this makes the envelope following transmitter more attractive to the wide-band applications.

摘要 i
ABSTRACT ii
致謝 iii
目錄 iv
表目錄 vii
圖目錄 viii
第一章 緒論 1
1.1 研究動機 1
1.2 研究發展現況 1
1.3 章節規劃 3
第二章 波包追隨式發射機架構 4
2.1 系統架構 4
2.2 波包路徑 4
2.2.1 切換式直流轉換器 5
2.2.1.1 Buck切換式直流轉換器 5
2.2.1.2 Boost切換式直流轉換器 7
2.2.1.3 Buck-Boost切換式直流轉換器 8
2.2.2 波包放大器 9
2.3 線性放大器 10
2.3.1 A類放大器 11
2.3.2 B類放大器 12
2.3.3 AB類放大器 12
2.4 系統性能參數 13
2.4.1 增益壓縮點 13
2.4.2 交互調變 14
2.4.3 效率 15
2.4.4 誤差向量振幅(EVM) 17
2.4.5 鄰近通道功率比(ACPR) 17
第三章 波包追隨式發射機實現 19
3.1 AB類功率放大器設計 19
3.1.1 負載線理論 19
3.1.2 模擬與量測 22
3.2 波包放大器分析與設計 25
3.2.1 模擬與量測 30
3.3 基頻電路設計 32
3.3.1 FPGA 32
3.3.1.1 直角坐標與極座標 33
3.3.1.2 延遲器設計 36
3.3.2 類比數位轉換器 37
3.3.3 數位類比轉換器 37
第四章 發射機量測 40
4.1 系統量測環境 40
4.2 數位調制訊號量測結果 41
4.2.1 固定偏壓 41
4.2.2 波包追隨 43
4.3 實驗比較 43
第五章 結論 47
參考文獻 48

[1]M. Iwamoto, A. Williams, P. Chen, A. G. Metgzer, L. E. Larsen, and P. M. Ashbeck, “An extended Doherty amplifier with high efficiency over a wide power range,” IEEE Trans. Microw. Theory Tech., vol. 49, no. 12, pp. 2472–2479 Dec. 2001.
[2]W. H. Doherty, “A new high efficiency power amplifier for modulated waves,” Proc. IRE, vol. 24, no. 9, pp. 1163–1182, Sept. 1936.
[3]G. Hanington, P. Chen, P. M. Asbeck and L. E. Larson, “High-efficiency power amplifier using dynamic power-supply voltage for CDMA applications,” IEEE Trans. Microw. Theory Tech., vol. 47, no. 8, pp. 1471–1476, Aug. 1999.
[4]J. Staudinger, B. Gilsdorf, D. Newman, G. Norris, G. Sadowniczak, R. Sherman, and T. Quach, “High efficiency CDMA power amplifier using dynamic envelope tracking technique,” in IEEE MTT-S Int. Microw. Symp. Dig., June 2000, pp. 873–876.
[5]B. Sahu and G. A. Ricon-Mora, “A high-efficiency linear RF power amplifier with a power-tracking dynamically adaptive buck-boost supply,” IEEE Trans. Microw. Theory and Tech., vol. 52, no. 1, pp. 112–120, Jan. 2004.
[6]D. C. Cox, “Linear amplification with nonlinear components,” IEEE Trans. Commun., vol. 22, no. 12, pp. 1942–1945, Dec. 1974.
[7]Y. Kim, Y. Shin and S. Im, “A memory mapping predistortion for the compensation with memory in OFDM system,” in Proc. IEEE Veh. Technol. Conf., vol. 1, July 1999, pp. 685–689.
[8]C. S. Yu, W. S. Chan and W. L. Chan, “1.9 GHz low loss varactor diode predistorter,” Electron. Lett., vol. 35, no. 20, pp. 1681–1682, Sept. 1999.
[9]M. Faulkner and M. Johansson, “Adaptive linearization using predistortion–experimental results,” IEEE Trans. on Veh. Technol., vol. 43, no. 2, pp. 323–332, May 1944.
[10]P. B. Kennington and D. Bennet, “Linear Distortion Correction Using a Feedforward System,” IEEE Trans. Veh. Technol, vol. 45, no. 1, pp. 74–81, Feb. 1996.
[11]P. B. Kenington, “Efficiency of feedforward amplifiers,” Proc. Inst. Elect. Eng., vol. 139, no. 5, pp. 591–593, Oct. 1992.
[12]L. R. Kahn, “Single-sideband transmission by envelope elimination and restoration,” Proc. IRE, vol. 40, no. 7, pp. 803–806, July 1952.
[13]M. Ranjan, K. H. Koo, G. Hanington, C. Fallesan, and P. Ashbeck, “Microwave power amplifiers with digitally-controlled power supply voltage for high efficiency and high linearity,” in IEEE MTT-S Int. Microw. Symp. Dig., June 2000, pp. 493–496.
[14]F. Wang, A. H. Yang, D. F. Kimball, L. E. Larson, and P. M. Asbeck, “Design of wide-bandwidth envelope-tracking power amplifiers for OFDM applications,” IEEE Trans. Microw. Theory Tech., vol. 53, no. 4, pp. 1244–1255, Apr. 2005.
[15]杜孟哲，採用極座標調制之射頻發射機，國立中山大學電機工程研究所碩士論文，2004。
[16]P. Reynaert and M. Steyaert "A 1.75 GHz polar modulated CMOS RF power amplifier for GSM-EDGE,” IEEE J. Solid-State Circuits, vol. 40, no. 12, pp. 2598–2608, Dec. 2005.
[17]K. C. Peng, J. k. Jau and T. S. Horng, “A novel transmitter using two-point delta-sigma modulation scheme for WLAN and 3G applications,” in IEEE MTT-S Int. Microw. Symp. Dig., June 2002, pp 1651–1654.
[18]W. Sander, S. Schell, and B. Sander, “Polar modulator for multi-mode cell phones,”Proc. CICC, pp. 439–445, Sept. 2003.
[19]陳奇燦，利用混合正交極座標調制器提升需要功率控制之第三代行動通訊發射機平均效率，國立中山大學電機工程研究所碩士論文，2007。
[20]C. J. Li, C. T. Chen , T. S. Horng, J. K. Jau and J. Y. Li, “High average-efficiency multimode RF transmitter using a hybrid quadrature polar modulator,” IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 55, no. 3, pp. 249–253, Mar. 2008.
[21]C. J. Li, C. T. Chen, , T. S. Horng, J. K. Jau, J. Y. Li, P. K. Horng and D. S. Deng, “A HQPM-Based Transmitter with Baseband Predistorter for Simultaneous Enhancement of ACPR and PAE,” Microwave Conference, 2007. APMC 2007. Asia-Pacific, Dec. 2007, pp. 1–4.
[22]I. Kim, J. Moon, J. Kim, J. Kim, C. S. Seo, K. O. Sun, C. W. Ahn and B. Kim, “Envelope injection consideration of high power hybrid EER transmitter for IEEE 802.16e mobile WiMAX application,” in IEEE MTT-S Int. Microw. Symp. Dig., June 2008 pp. 411–414.
[23]I. Kim, Y. Woo, J. Kim, J. Moon, J. Kim and B. Kim, "High-efficiency hybrid EER transmitter using optimized power amplifier,” IEEE Trans. Microw. Theory Tech., vol. 56, no. 11, pp. 2582–2593, Nov. 2008.
[24]R. Andraka, “A survey of CORDIC algorithms for FPGA based computers,” in Proc. Field Programmable Gate Arrays, 1988, pp. 191–200.
[25]F. Wang, D. F. Kimball, J. D. Popp, A. H. Yang, D. Y. Lie, P. M. Asbeck and L. E. Larson, “An improved power-added efficiency 19-dBm hybrid envelope elimination and restoration power amplifier for 802.11g WLAN applications,” IEEE Trans. Microw. Theory Tech., vol. 54, no. 12, pp. 4086–4099 Dec. 2006.
[26]F. Wang, A. Ojo, D. Kimball, P. Asbeck and L. Larson, “Envelope tracking power amplifier with pre-distortion linearization for WLAN 802.11g,” in IEEE MTT-S Int. Microw. Symp. Dig., vol.3, pp. 1543–1546, June 2004.
[27]張盛富、張嘉展，無線通訊射頻晶片模組設計－射頻系統篇，台北縣：全華，2008。
[28]B. Razavi, RF Microelectronics, Prentice Hall, 1998.
[29]S. C. Cripps, “A theory for the prediction of GaAs FET loadpull power contours,“ IEEE MTT-S Int. Microw. Symp. Dig., June 1983, pp. 221–223.
[30]S. C. Cripps, RF Power Amplifiers for Wireless Communications, Norwood, MA: Artech House, 2006.
[31]張盛富、張嘉展，無線通訊射頻晶片模組設計－射頻晶片篇，台北縣：全華，2007。
[32]J. E. Volder, “The CORDIC trigonometric computing technique,” IRE Trans. Electron. Comput., vol. 8, pp.330–334 1959