基于PIN二极管的动态信号反馈增益调控电路
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摘要
为了实现超宽带可变增益放大器在超宽频带内增益变化的一致性和增益平坦度,需要一个增益调控单元在保证其大的增益变化范围的同时对平坦度进行调节.为此,提出一款基于PIN二极管的动态信号反馈增益调控电路,PIN二极管作为增益反馈的可变阻抗实现动态信号增益调控,串联电感与电容构成带通滤波器选择增益需要调整的频带.建立了PIN二极管的等效电路模型,并采用e函数形式拟合确定其不同频率时的等效阻抗参数.利用包含PIN二极管的动态信号反馈电路的高频小信号等效模型,分析了调控电路的动态反馈调节机制,研究结果表明:该动态信号反馈增益调控电路能够对可选频带范围内变化较大的增益进行调节,使整个频带保持一致的变化范围,同时对于每一个变化增益,都保持良好的增益平坦度.
To achieve the gain consistency and gain flatness of an ultra wideband variable gain amplifier in ultra wideband,a gain control unit is required to ensure the wide gain variation range mean and adjust the gain flatness. In this paper,a dynamic signal feedback gain control circuit based on PIN diode was proposed and the PIN diode was used as the variable impedance of the gain feedback to implement dynamic signal gain control. The serial inductor and capacitor formed the band-pass filter to select the frequency band needed to adjust its gain. Furthermore,the equivalent circuit model of PIN diode was established and the equivalent impedance parameter under different frequencies was determined by efunction fitting. The dynamic feedback adjustment mechanism of the control circuit was analyzed by using the high frequency equivalent small signal model of the dynamic signal feedback circuit. Result shows that the dynamic gain feedback control circuit can adjust the gain of the frequency band,which has large gain fluctuation to keep the whole frequency band in a consistent range. As the same time,the dynamic gain feedback can maintain a good gain flatness for each variable gain.
To achieve the gain consistency and gain flatness of an ultra wideband variable gain amplifier in ultra wideband,a gain control unit is required to ensure the wide gain variation range mean and adjust the gain flatness. In this paper,a dynamic signal feedback gain control circuit based on PIN diode was proposed and the PIN diode was used as the variable impedance of the gain feedback to implement dynamic signal gain control. The serial inductor and capacitor formed the band-pass filter to select the frequency band needed to adjust its gain. Furthermore,the equivalent circuit model of PIN diode was established and the equivalent impedance parameter under different frequencies was determined by efunction fitting. The dynamic feedback adjustment mechanism of the control circuit was analyzed by using the high frequency equivalent small signal model of the dynamic signal feedback circuit. Result shows that the dynamic gain feedback control circuit can adjust the gain of the frequency band,which has large gain fluctuation to keep the whole frequency band in a consistent range. As the same time,the dynamic gain feedback can maintain a good gain flatness for each variable gain.
引文
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[10]张万荣,黄鑫,金冬月,等.一种增益可多重调节的低功耗双频段低噪声放大器[J].北京工业大学学报,2017,43(4):566-573.ZHANG W R,HUANG X,JIN D Y,et al. Dual-band low noise amplifier with multiple gain-tunability and low power consumption[J]. Journal of Beijing University of Technology,2017,43(4):566-573.(in Chinese)
[2]王自强,池保勇,王志华. CMOS可变增益放大器设计概述[J].微电子学,2005,35(6):612-617.WANG Z Q,CHI B Y,WANG Z H. An overview of CMOS variable gain amplifiers[J] Acta Electronica Sinica,2005,35(6):612-617.(in Chinese)
[3] KITAMURA R,TSUKIZAWA T,SAITO N,et al. An 84d B-gain-range and 1 GHz-bandwidth variable gain amplifier using gain flattening capacitors for multi-gigabit radio[C]∥Radio and Wireless Symposium. Piscataway:IEEE,2013:220-222.
[4] ABDEL-HAFEZ I L,KHALAF Y A,FARAG F A. Design of wide band PVGA for UWB applications[C]∥Electronics Communications and Photonics Conference.Piscataway:IEEE,2011:1-4.
[5] XIAO J,MEHR I,SILVA-MARTINEZ J. A high dynamic range CMOS variable gain amplifier for mobile DTV tuner[J]. IEEE Journal of Solid-state Circuits,2007,42(2):292-301.
[6]丁家峰. PIN二极管的物理机制、仿真模型及其应用研究[D].长沙:中南大学,2001.DING J F. Studies on mechanism,simulation models and applications of the PIN diode abstract[D]. Changsha:Central South University,2001.(in Chinese)
[7]刘恩科.半导体物理学[M].北京:电子工业出版社,2013:168.
[8]童诗白.模拟电子技术基础[M].北京:高等教育出版社,2010:226-227.
[9] XIA K,NIU G,SHERIDAN D C,et al. Frequency and bias-dependent modeling of correlated base and collector current RF noise in Si Ge HBTs using quasi-static equivalent circuit[J]. IEEE Transactions on Electron Devices,2006,53(3):515-522.
[10]张万荣,黄鑫,金冬月,等.一种增益可多重调节的低功耗双频段低噪声放大器[J].北京工业大学学报,2017,43(4):566-573.ZHANG W R,HUANG X,JIN D Y,et al. Dual-band low noise amplifier with multiple gain-tunability and low power consumption[J]. Journal of Beijing University of Technology,2017,43(4):566-573.(in Chinese)