振盪器頻率牽引效應對鎖相迴路影響之系統模型建立

在無線通訊系統中，本地振盪源多以鎖相迴路為基礎的頻率合成器設計為主，而頻率合成器的頻譜純淨度乃是影響訊號品質的關鍵之一。由於振盪器容易受到訊號干擾的特性，將使得鎖相迴路的輸出頻譜在受到訊號注入情況下受到汙染。由於振盪器受訊號注入的影響是一種高度非線性的機制，在數學分析中往往需要配合特殊的假設才能更進一步導出結果；由此可知，注入干擾訊號對實際系統影響分析的困難度已不言而喻，這也使得設計者很難評估干擾訊號對系統所造成的影響。本論文旨在將傳統的注入鎖定方程式推廣為離散時域方程式，進而可以發展出一種基於電腦輔助設計軟體的注入鎖定振盪器模型，使注入訊號的影響可以借助電腦演算來完成。有別於現有文獻的方法，本論文使用波包模擬的觀念來實現注入鎖定振盪器的行為模型，在相同的準確性下能夠具有更好的模擬效率。本論文將此模型之演算結果與實際受注入的振盪器輸出頻譜進行比較，以確認此受注入影響振盪器模型之準確性。隨後，以鎖相迴路之鎖相振盪器為基礎，將所建立的注入鎖定振盪器模型套用於鎖相式自我注入鎖定架構之上並進行完整的模擬與量測結果比較。

關鍵字

頻率牽引；鎖相迴路；注入鎖定；相式自我注入鎖定

並列摘要

In the wireless communication systems, the local oscillator (LO) is usually based on the phase-locked loop (PLL) in the transceiver to generate a carrier with purity. The spectral purity of the synthesized output is one of the reasons that affect the system output quality. Since the oscillator is susceptible to the interferences, the PLL output spectrum is subject to degradation due to external disturbances. It is difficult to analyze the oscillator under injection, because of the highly nonlinear mechanism, unless some particular conditions are restricted. This thesis has developed an injection-locked oscillator (ILO) model based on the discrete-time algorithm driven from the Adler’s equation. The developed ILO model can lead the designers to evaluate the influence of injection in a simple manner. In this study, the accuracy of the ILO model was experimentally examined. The model was finally applying itself to a 2.4 GHz phase- and self-injection-locked (PSIL) radar to predict the vital-sign sensing results.

並列關鍵字

frequency pulling ； phase-locked loop ； injection-locked ； phase- and self-injection-locked

參考文獻

[1] C.-J. Li, C.-H. Hsiao, F.-K. Wang, T.-S. Hong, and K.-C, Peng, “A rigorous analysis of a phase-locked oscillator under injection,” IEEE Trans. Microw. Theory Tech., vol. 58. no. 5, pp. 1391–1400, May 2010.

[2] R. Adler, “A study of locking phenomena in oscillator,” Proc. IRE, vol. 34, no. 6, pp. 351–357, June 1946.

[3] B. Razavi, “Challenges in portable RF transceiver design,” IEEE Circuits Devices Mag., vol. 12, no. 5, pp. 12–25, Sep. 1996.

[4] B. Razavi, “RF transmitter architectures and circuits,” in Proc. IEEE Custom Integr. Circuits Conf., San Diego, CA, 1999, pp. 197–204.

[6] P.-H. Wu, J.-K. Jau, C.-J. Li, T.-S. Hong, and P. Hsu, “Phase- and self-injection-locked radar for detecting vital signs with efficient elimination of dc offsets and null points,” IEEE Trans. Microw. Theory Tech., vol. 61, no. 1, pp. 685–695, Jan. 2013.

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振盪器頻率牽引效應對鎖相迴路影響之系統模型建立

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