應用於K頻帶與V頻帶壓控振盪器之設計與實現

Design and Implementation of Voltage-Controlled Oscillator for K-band and V-band System Applications.

尤伯瑋(Po-Wei Yu)

指導教授 ： 林佑昇

國立暨南國際大學/科技學院/電機工程學系/碩士(2010年)

https://doi.org/10.6837/NCNU.2010.00038

摘要

本論文以壓控震盪器為研究目標。研究主題分成兩部分：
第一部分為可調式源極衰減技術壓控振盪器，可調式源極衰減技術可以降低MOS寄生電容Cgs而提高可調範圍。此部份以兩個實例來探討，第一個實例是利用Push-Push 的技巧來達到雙頻應用以及加寬2倍頻的可調範圍並且探討高壓控振盪器增益與低控振盪器增益所帶來的影響，量測結果在電壓0.9伏之下，在K頻段可調範圍為27.7 GHz 到 28.7 GHz (1 GHz 3.55%)，輸出功率為0.54±0.34 dBm，在V頻段可調範圍為55.17 GHz 到 58.12 GHz (2.59 GHz 5.2%)，輸出功率為-19.99±1.4 dBm，由此可以看見V頻段的可調範圍是K頻段的2倍，但是輸出功率較低。
第二的實例是利用變壓器回授之壓控振盪器，此架構有較佳的相位雜訊，以及較大輸出功率，由於變壓器回授會造成較窄的可調範圍，故利用可調式源極衰減技術來拉大可調範圍，在模擬結果來看，在電壓0.85伏供應之下可調範圍為21.48 GHz到 24.67 GH (3.19 GHz 13.86%)，輸出功率為0.53±1.37 dBm，最低的相位雜訊為 -103.33 dBc/Hz。
第二部分是利用操作在中等反轉區P型場效電晶體當電流源來達到低電流，藉由改變交叉偶和對的電晶體臨界電壓來達到低電壓，由上面兩個因素來達到低功耗的設計，並且利用交叉偶和對的寄生電容來達到頻率可調的效果，再利用4個電晶體來偶和兩組壓控振盪器來完成四相位輸出，在量測結果來看，在0.63伏的電壓下，可調範圍為1.11 GHz 到 11.55 GHz (440 MHz 3.88%)，輸出功率為-6.8±2.3 dBm，在1 MHz的偏移量相位雜訊為 -114.668 dBc/Hz，在功耗方面，單組壓控振盪器的功耗為0.85mW，整體四相位壓控振盪器核心部分的功耗為1.7mW，在前面兩個因素之下確實達到低功耗的要求，非常適合用在低功耗系統。

關鍵字

壓控震盪器 ； 源極衰減 ； 次諧波 ； 四相位 ； 中反轉區 ； 臨界電壓

並列摘要

The aim of this thesis is to design Voltage-Controlled Oscillator (VCO) and. The research theme can be divided into two parts：
The first part is the CMOS VCO using tunable LC source-degeneration. This technique can decrease the MOS parasitic capacitor Cgs and increase the tuning range. This part has conferred by two cases. The first case is using the push-push structure to achieve two band system application and twice wide tunning range. This case also discussion the influence of high KVCO and low KVCO. The measurement results when the power supply voltage is 0.8V. At K-band, the tunning range is 27.7 GHz to 28.7 GHz (1 GHz 3.55%) and the output power is 0.54±0.34 dBm. At V-band, the tunning range is55.17 GHz to 58.12 GHz (2.59 GHz 5.2%) and the output power is-19.99±1.4 dBm. From the measurement results, the V-band tunning range is twice of the K-band but this signal output power is lower.
The second case is utilizing the transformer feedback technique to design VCO. This structure has better phase noise and large output power. Because the transformer is similar feedback, the tunning range is narrow. So this structure also use the tunable LC source-degeneration to make the tunning range wide. The simulation results when the power supply voltage is 0.85V, the tunninge range is 21.48 GHz to 24.67 GH (3.19 GHz 13.86%). The output power is 0.53±1.37 dBm and the lowest of phase noiste at 1 MHz offset is -103.33 dBc/Hz.
The second part is using the current which the PMOS work at moderate inversion to achieve low current and decrease the threshold voltage to achieve low voltage circuit. Therefore, the low power circuit design has realizing. This design alse use the intrinsic-tuned technique to tune the oscillation frequency and use four NMOS to couple the signal of two VCO and realize the quadrature signal. The measurement result when the power supply voltage is 0.63V, the tunning range is 1.11 GHz to 11.55 GHz (440 MHz 3.88%). The output power is -6.8±2.3 dBm and the phase noise at 1 MHz offset is -114.668 dBc/Hz. The power consumption of the VCO and QVCO are 0.85mW and 1.7mW. This very suitable for low power system.

並列關鍵字

voltage-controlled oscillator ； source-degeneration ； sub-harmonic ； quadrature ； moderate inversion ； threshold voltage

參考文獻

[1] 袁帝文, 王岳華, 謝孟翰, 王弘毅, “高頻通訊電路設計” 高立圖書有限公司, 1998.

[2] B. Razavi, RF Microelectronics. Upper Saddle River, NJ: Prentice-Hall, 1998.

[3] F. Ellinger, Radio Frequency Integrated Circuit and Technologies, Springer, 2007.

[4] D. M. Pozar, Microwave engineering, John Wiley & Sons, 2005.

[5] Chuan-Wei Tsou, Chi-Chen Chen, Yo-Sheng Lin, “A 57-GHz CMOS VCO with 185.3% tuning-range enhancement using tunable LC source-degeneration,”VLSI Design, Automation and Test, 2009. VLSI-DAT '09. International Symposium on 28-30 April 2009 Page(s):146 – 149