展宽文氏桥振荡器调谐范围的新方法

New Methods of Widening Wien-bridge Oscillator's Tuning Range

本文对限制文氏桥振荡器调谐范围的主要原因作了分拆.为了展定文氏桥振荡器的调谐范围,文中利用复合型运算放大器来补偿单运放有限的增益带宽税的不利影响,并采用开关电容等效电阻,以获得稳定的大时间常数.实验结果表明了该方案的有效性,并已成功地应用于宽带高精度信号源的设计.

In this paper, reasons that restrlot Wien - bridge aseillator's tuning range are discussed. In order to widen the tuning range,composite op amp is sussestal to compensate the unfavor -able effect ot finite gain-bandwidth product of single op amp on high trequency praperty of the oscillator. on th. other han,switched capacitor is proposed to take place of resistot in RC feedbackloop and obtaln large time canstant. Theorehtal analpe is consistent with the experimental rarelts.This method has ben od to design wide-band sinusoidal signal generator wasssfully.