Log-domain quadrature sinusoidal oscillator based on lossless integrator and all-pass filter

Abstract

A log-domain current-mode quadrature sinusoidal oscillator based on all-pass filter and lossless integrator is presented. The oscillator is realized by a first-order differential equation for obtaining all pass filter and lossless integrator. The proposed oscillator can be electronically tuned by adjusting bias currents. The proposed oscillator contains 18 NPN transistors, 2 grounded capacitors and 11 bias currents for achieving low-power and fast response. A validated BJT model is used in SPICE simulation operated from a single power supply as low as 2.5V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortion of signal output is obtained around 0.55%. The oscillation frequency can be operated more than 100MHz which enables fully integrated in telecommunication systems and suitable for high-frequency applications. SPICE simulation results are included. © 2011 IEEE.