Marcos Carlos, Sánchez-Pena José M, Torres Juan C, Pérez Isabel, Urruchi Virginia
Departamento de Tecnología Electrónica, Universidad Carlos III, Avenida de la Universidad 30, Leganés E28911, Madrid, Spain.
Rev Sci Instrum. 2011 Dec;82(12):126101. doi: 10.1063/1.3666865.
A phase-locked loop is demonstrated using a twisted-nematic liquid crystal cell as a capacitance that can be varied as a function of applied voltage. The system is formed by a phase detector, a low-pass filter, as well as a voltage controlled oscillator including such variable capacitance. A theoretical study is proposed and experimentally validated. Capture and locked ranges of hundreds of kHz have been obtained for the configuration used in this circuit. An application as frequency demodulator using a practical implementation of this circuit has been demonstrated.
利用扭曲向列型液晶盒作为电容，该电容可随施加电压而变化，展示了一种锁相环。该系统由一个鉴相器、一个低通滤波器以及一个包含这种可变电容的压控振荡器组成。提出了一项理论研究并通过实验进行了验证。对于该电路中使用的配置，已获得数百千赫兹的捕获范围和锁定范围。已经展示了使用该电路的实际实现作为频率解调器的应用。
