A quadrature based voltage controlled oscillator (VCO) local oscillator (LO) system is disclosed. The system includes a phase detector, a quadrature phase VCO, a quadrature control path, an in-phase control path, and an in-phase VCO. The phase detector is configured to compare and generate phase error between a reference clock and an in-phase VCO output. The quadrature control path configured to generate a quadrature control voltage based on a quadrature VCO output and the in-phase VCO output. The quadrature phase VCO configured to generate the quadrature VCO output based on the quadrature control voltage and the generated phase error. The in-phase control path configured to generate an in-phase control voltage based on the quadrature VCO output and the in-phase VCO output. The in-phase VCO is configured to generate the in-phase VCO output based on the in-phase control voltage and the generated phase error. An all digital dual mode phase locked/phase tracking loop LO generate system is also disclosed.