Introduction CLOCK OSCILLATORS (CXO) PRECISION CLOCK OSCILLATORS(PXO) VOLTAGE CONTROLLED OSCILLATORS (VCXO) TEMPERATURE COMPENSATED OSCILLATORS (TCXO) TEMPERATURE COMPENSATED VOLTAGE CONTROLLED OSCILLATORS(VC-TCXO) OVEN CONTROLLED CRYSTAL OSCILLATORS(OCXO) QUARTZ CRYSTAL UNITS Oscillators Use Parametric Multiplication Method