An RC oscillator has a variable capacitor that sets the output frequency. The variable capacitor has m binary-weighted switched capacitor arrays, and each binary-weighted switched capacitor array has binary-weighted capacitors. p binary bits are decoded into an m-bit thermometer code that selects one of the m binary-weighted switched capacitor arrays to use n binary bits to switch its binary-weighted capacitors. Other binary-weighted switched capacitor arrays have all their capacitors switched on, or all their capacitors switched off by the thermometer code. The smallest or unit capacitance of each binary-weighted switched capacitor array is adjusted to compensate for the non-linear reciprocal relationship of frequency being proportional to 1/RC. The unit capacitance is increased for each successive binary-weighted switched capacitor array to reset to the ideal linear relationship of the (p,n)-bit code to frequency.

This temperature-compensated crystal oscillator includes: a crystal resonator; first and second MOS-type variable capacitance elements, each having one end electrically connected to first or second electrodes of the crystal resonator; and a temperature compensation circuit that applies a temperature compensation voltage, which changes in accordance with a temperature, to other ends of the first and second MOS-type variable capacitance elements. The first MOS-type variable capacitance element includes a first back gate provided within a semiconductor substrate, and an N-type first gate electrode provided above the first back gate with an insulating film interposed therebetween; and the second MOS-type variable capacitance element includes a second back gate provided within the semiconductor substrate and having the same conductivity type as the first back gate, and a P-type second gate electrode provided above the second back gate with an insulating film interposed therebetween.

An oscillator includes: an oscillation stage circuit that is connected between a first electrode and a second electrode of a resonator and performs an oscillation operation; a variable capacitance element that is connected to the first or second electrode of the resonator and adjusts an oscillation frequency; a bandgap reference circuit that generates a reference voltage having magnitude, which changes depending on the temperature, by using a resistor inserted in a current path through which a current having magnitude, which changes depending on the temperature flows; and a bias current generating circuit that generates a bias current of the oscillation stage circuit based on the reference voltage, and that, thereby, reduces a change in the oscillation frequency due to the temperature dependence of the impedance of the resonator or the temperature dependence of the sensitivity of the variable capacitance element.

A microelectromechanical device structure comprises a supporting structure wafer. A cavity electrode is formed within a cavity in the supporting structure wafer. The cavity electrode forms a protruding structure from a base of the cavity towards the functional layer, and the cavity electrode is connected to a defined electrical potential. The cavity electrode comprises a silicon column within the cavity in the supporting structure wafer, which is partially or entirely surrounded by a cavity. One or more cavity electrodes may be utilized for adjusting a frequency of an oscillation occurring within the functional layer.

An RC oscillator has a variable capacitor that sets the output frequency. The variable capacitor has m binary-weighted switched capacitor arrays, and each binary-weighted switched capacitor array has binary-weighted capacitors. p binary bits are decoded into an m-bit thermometer code that selects one of the m binary-weighted switched capacitor arrays to use n binary bits to switch its binary-weighted capacitors. Other binary-weighted switched capacitor arrays have all their capacitors switched on, or all their capacitors switched off by the thermometer code. The smallest or unit capacitance of each binary-weighted switched capacitor array is adjusted to compensate for the non-linear reciprocal relationship of frequency being proportional to 1/RC. The unit capacitance is increased for each successive binary-weighted switched capacitor array to reset to the ideal linear relationship of the (p,n)-bit code to frequency.

Apparatus and methods for frequency tuning of rotary traveling wave oscillators (RTWOs) are provided herein. In certain configurations, distributed quantized tuning is used to tune a frequency of the RTWO. The RTWO includes a plurality of segments distributed around the RTWO's ring, and the segments include tuning capacitors and other circuitry. The distributed quantized frequency tuning is used to control the tuning capacitors in the RTWO's segments using separately controllable code values, thereby enhancing the RTWO's frequency step size or resolution. Moreover, in configurations including multiple RTWO rings that are locked to one another to reduce phase noise, the distributed quantized frequency tuning can be used to separately set the tuning capacitors across multiple RTWO rings that are coupled to one another.

The present invention provides a voltage waveform shaping oscillator, including a signal source and a coupling transformer. An output end of the signal source is connected to an input end of the coupling transformer, and an input end of the signal source is connected to an output end of the coupling transformer. The signal source is configured to: receive, by using the input end of the signal source, a quasi-square wave signal output by the output end of the coupling transformer, generate an original signal based on the quasi-square wave signal, and send the original signal to the input end of the coupling transformer by using the output end of the signal source. The coupling transformer is configured to: perform filtering processing on the original signal to obtain the quasi-square wave signal. The voltage waveform shaping oscillator is configured to reduce phase noise of an oscillator.

The disclosure is directed to a frequency synthesizer circuit including digitally controlled oscillator (DCO) and an injection locked digitally controlled oscillator (ILD). The ILD outputs a signal with a frequency that is some fraction of the frequency of the DCO output signal and locked in phase to the DCO output signal. The frequency synthesizer circuit drives the ILD with the same modulation input signal that drives the DCO, with the modulation input signal scaled to account for any mismatch between the gains of the DCO and ILD. Driving the ILD with the same, scaled modulation signal as the main DCO minimizes the frequency offset between the DCO output signal and the divided natural oscillation frequency of the ILD. Minimizing the frequency offset makes the lock of the ILD more robust and reduces jitter contribution from the ILD.

An integrated circuit device is described. The integrated circuit device comprises a substrate; a plurality of metal routing interconnect layers; an inductor formed in at least one metal layer of the plurality of metal routing interconnect layers; and a bottom metal layer between the plurality of metal routing interconnect layers and the substrate; wherein a pattern ground shield is formed in the bottom metal layer. A method of implementing an integrated circuit device is also disclosed.

In accordance with an embodiment, a voltage controlled oscillator (VCO) includes a VCO core having a plurality of transistors and a varactor circuit that has a first end coupled to emitter terminals of the VCO core and a second end coupled to a tuning terminal. The varactor circuit includes a capacitance that increases with increasing voltage applied to the tuning terminal with respect to the emitter terminals of the VCO core.