Nth-order arbitrary-phase-shift sinusoidal oscillator structure and analytical synthesis method of making the same

摘要

Nth-order voltage- and current-mode arbitrary phase shift oscillator structures are synthesized using n operational trans-conductance amplifiers (OTAs) or second-generation current controlled conveyors (CCCIIs) and n grounded capacitors. Linking up the I/O characteristics of the OTA and the CCCII and the reactance of grounded capacitor, the step of synthesis is first based on the algebraic analysis to oscillatory characteristic equations, resulting in a quadrature oscillator structure. Secondly, instead of the quadrature characteristic, to control each output signal with one another by a desired phase difference or 90°, selectively superposing any of two fundamental OTA/CCCII-C sub-circuitries benefits the transformation of quadrature to arbitrary-phase-shift characteristic for the sinusoidal oscillator structure. Furthermore, several compensation schemes are presented for reducing the output parameter deviation due to the non-ideal effects.