An oscillator apparatus, characterized by: an oscillator core circuit, comprising: an inverting transconductance amplifier; at least one first capacitor (1053A, 4053A), connected between an input of the inverting transconductance amplifier and a ground level; at least one second capacitor (1053B, 4053B), connected between an output of the inverting transconductance amplifier and the ground level; and a resonator, having a first port connected to the input of the inverting transconductance amplifier and a second port connected to the output of the inverting transconductance amplifier, the first port being decoupled from the second port, so the common mode of the two ports can be defined independently; a DC coupling circuit, having one end connected to the input of the inverting transconductance amplifier and the first port and having another end connected to a driver; and the driver, having an input DC coupled to the first port via the DC coupling circuit, characterized by a bias circuit comprising: an inverter, biased and controlled by a specific current of a current source, an output of the inverter being connected to an input of the inverter; and a resistor, connected between the first port of the resonator and the input of the inverter; wherein the driver is further biased by the specific current of the current source. an oscillator core circuit, comprising: an inverting transconductance amplifier; at least one first capacitor (1053A, 4053A), connected between an input of the inverting transconductance amplifier and a ground level; at least one second capacitor (1053B, 4053B), connected between an output of the inverting transconductance amplifier and the ground level; and a resonator, having a first port connected to the input of the inverting transconductance amplifier and a second port connected to the output of the inverting transconductance amplifier, the first port being decoupled from the second port, so the common mode of the two ports can be defined independently; a DC coupling circuit, having one end connected to the input of the inverting transconductance amplifier and the first port and having another end connected to a driver; and the driver, having an input DC coupled to the first port via the DC coupling circuit, characterized by a bias circuit comprising: an inverter, biased and controlled by a specific current of a current source, an output of the inverter being connected to an input of the inverter; and a resistor, connected between the first port of the resonator and the input of the inverter; wherein the driver is further biased by the specific current of the current source. an inverting transconductance amplifier; at least one first capacitor (1053A, 4053A), connected between an input of the inverting transconductance amplifier and a ground level; at least one second capacitor (1053B, 4053B), connected between an output of the inverting transconductance amplifier and the ground level; and a resonator, having a first port connected to the input of the inverting transconductance amplifier and a second port connected to the output of the inverting transconductance amplifier, the first port being decoupled from the second port, so the common mode of the two ports can be defined independently; a DC coupling circuit, having one end connected to the input of the inverting transconductance amplifier and the first port and having another end connected to a driver; and the driver, having an input DC coupled to the first port via the DC coupling circuit, characterized by a bias circuit comprising: an inverter, biased and controlled by a specific current of a current source, an output of the inverter being connected to an input of the inverter; and a resistor, connected between the first port of the resonator and the input of the inverter; an inverter, biased and controlled by a specific current of a current source, an output of the inverter being connected to an input of the inverter; and a resistor, connected between the first port of the resonator and the input of the inverter; wherein the driver is further biased by the specific current of the current source.