Ahmed S. Elwakil, et al., "Sinusoidal oscillators with lower gain requirements at higher frequencies based on an explicit tanh (x) nonlinearity." International Journal of Circuit Theory and Applications 38, (7), 2010, 747.
Two novel sinusoidal oscillator structures with an explicit tanh(x) nonlinearity are proposed. The oscillators have the attractive feature: the higher the operating frequency, the lower the necessary gain required to start oscillations. A nonlinear model for the two oscillators is derived and verified numerically. Spice simulations using AMS BiCMOS 0.35µ model parameters and experimental results are shown. Copyright © 2009 John Wiley & Sons, Ltd.