A voltage controlled oscillator includes a first inductor; a first variable capacitance unit including a first variable capacitance element having a variable capacitance and a second variable capacitance element having a variable capacitance; a first node configured for application of a first voltage to the first variable capacitance unit; a cross-coupled unit including a first transistor and a second transistor, an output of the first transistor connected to an input of the second transistor; a current source configured to flow a current through the first inductor, the first transistor, and the second transistor; a second variable capacitance unit including a third variable capacitance element having a variable capacitance, and a fourth variable capacitance element having a variable capacitance; and a second node different from the first node configured for application of a second voltage to the second variable capacitance unit.

A crystal oscillator includes an inverter configured to receive a first voltage at a first node and output a second voltage at a second node, a stacked-diode feedback network inserted between the first node and the second node, a waveform shaper configured to couple the second node to a third node in accordance with the first voltage, a crystal inserted between a fourth node and a fifth node, wherein the fourth node is coupled to the third node, and the fifth node is coupled to the first node, a first shunt capacitor inserted between the fourth node and a ground node, and a second shunt capacitor inserted between the fifth node to and the ground node.

An oscillator includes a first resonator element, a first circuit element configured to oscillate the first resonator element to generate a first oscillation signal, a first package which is configured to house the first resonator element and the first circuit element, and has a mounting surface and a mounting terminal disposed on the mounting surface, a second resonator element an oscillation frequency of which is controlled based on the first oscillation signal, and a second package which houses the second resonator element and is provided with the second package mounted on the mounting surface of the first package.

An oscillation circuit has a charge-discharge type oscillation unit that performs an oscillation operation at an oscillating frequency that is in accordance with a control current value, and a control current generation unit that generates the control current. The control current generation unit includes a reference voltage generation circuit that generates a reference voltage that has a first temperature characteristic, a temperature characteristic slope correction circuit that corrects a slope of a temperature characteristic of a reference voltage in accordance with first correction information and generates an output voltage that has a second temperature characteristic, and a voltage-current conversion circuit that converts the output voltage of the temperature characteristic slope correction circuit into the control voltage, and that corrects the control current value in accordance with second correction information.

An apparatus is provided which comprises: a crystal having an input and an output; a first interconnect line having first and second ends, wherein the first end is coupled to the input; a second interconnect line having first and second ends, wherein the first end is coupled to the output; a first capacitor coupled to the input and ground; and a second capacitor coupled to the second end of the second interconnect line. An apparatus is provided which comprises: a high pass filter; a pair of AC coupling capacitors coupled to the high pass filter; a low pass filter coupled to the pair of AC coupling capacitors; and an analog to digital converter (ADC) coupled to the low pass filter.

An oscillator includes a resonator and a first loop circuit. The first loop circuit includes an amplifier and a first coupler. That first loop circuit is electrically coupled to the resonator. The oscillator is configured to produce negative feedback for the amplifier in a cavity mode relative to short circuit terminations or open circuit terminations of a cavity modelling the oscillator at frequencies offset from a carrier frequency. The oscillator has a loss of less than 4.00 dB for a bidirectional trip through the cavity at the frequencies offset from the carrier frequency.

An oscillator includes a first resonator element, a first circuit element configured to oscillate the first resonator element to generate a first oscillation signal, a first package which is configured to house the first resonator element and the first circuit element, and has a mounting surface and a mounting terminal disposed on the mounting surface, a second resonator element an oscillation frequency of which is controlled based on the first oscillation signal, and a second package which houses the second resonator element and is provided with the second package mounted on the mounting surface of the first package.

Disclosures of the present invention particularly describe oscillator circuit with temperature compensation function, consisting of a fully differential amplifier, a current mirror unit, a bias current supplying unit, a compensation unit, and a reference signal generating unit. A variety of experimental data have proved that, based on the normal operation of the compensation unit and the reference signal generating unit, an oscillation frequency of this oscillator circuit would be maintained at same level even if the ambient temperature continuously increases. Therefore, because the frequency drift due to temperature variation would not occur in the oscillator circuit of the present invention, the novel oscillator circuit is potential oscillator to replace the conventional oscillators applied in analog-to-digital convertors or time-to-digital convertors.

A circuit and method include using a first source follower of a first type to receive a first voltage from a first node and output a first current to a third node; using a second source follower of a second type to receive a second voltage from a second node and output a second current to the third node; using an AC (alternate current) coupling capacitor to couple the first node to the second node; using a feedback capacitor to couple the third node to the first node; using a shunt capacitor to shunt the third node to an AC ground; using a crystal to shunt the first node to an AC ground; providing a first bias voltage to the first node via a first DC (direct current) coupling resistor; and providing a second bias voltage to the second node via a second DC coupling resistor.

A quadrature oscillator includes a first oscillator that outputs a first differential signal, and a second oscillator that outputs a second differential signal having phases that are different from those of the first differential signal, wherein the first oscillator includes a first LC resonator having an inductor and a capacitor coupled in parallel, a first cross-coupled circuit having a first pair of cross-coupled transistors coupled to the first LC resonator, a first tail current source coupled to the first pair of transistors, first input differential pair transistors to which the second differential signal is to be input, and a first pair of harmonic resonators disposed in input sections of the first input differential pair transistors, the first pair of the harmonic resonators have a resonance frequency of an odd multiple of a resonance frequency of the first oscillator.