Multiphase sinusoidal oscillators using Operational Trans-Resistance Amplifier

In this paper operational trans-resistance amplifier (OTRA) based multiphase sinusoidal oscillator circuits are presented. The first circuit produces n odd-phase oscillations of equal amplitudes and equally spaced in phase. The second circuit is capable of producing n odd or even phase oscillations equally spaced in phase. An alternative approach is discussed in the third circuit, which utilizes a single phase tunable oscillator circuit which is used to inject signals into a phase shifter circuit. An automatic gain control (AGC) circuit has been implemented for the second and third circuit. The circuits are simple to realize and have a low component count. PSpice simulations have been given to verify the theoretical analysis.