A radio device comprises a radio transceiver, a resonator, a temperature measurement unit, a frequency synthesiser and a processing system. A temperature signal from the temperature measurement unit, representative of a measured temperature of the resonator, is used to determine an estimated frequency offset for the resonator at the measured temperature using a model stored in a memory of the processing system that relates frequency offset to temperature. A periodic signal from the resonator is provided to the frequency synthesizer, which, in dependence on the estimated frequency offset, is used to generate a periodic local signal. The radio transceiver receives a radio signal comprising a periodic component at a received signal frequency. An error value representative of a difference between the received signal frequency and a frequency of the periodic local signal is determined and used to update one or more parameters of the model stored in the memory.

A clock integrated circuit is provided. The clock integrated circuit includes: a first clock generator which includes a crystal oscillator configured to generate a first clock signal; and a second clock generator which includes a resistance-capacitance (RC) oscillator and a first frequency divider, and is configured to: generate a second clock signal using the first frequency divider based on a clock signal output from the RC oscillator; perform a first calibration operation for adjusting a frequency division ratio of the first frequency divider to a first frequency division ratio based on the first clock signal; and perform a second calibration operation for adjusting the first frequency division ratio to a second frequency division ratio based on a sensed temperature.

A dual-output microelectromechanical system (MEMS) resonator can be operated selectively and concurrently in an in-plane mode of vibration and an out-of-plane mode of vibration to obtain, respectively, a first electrical signal having a first frequency and a second electrical signal having a second frequency that is less than the first frequency. The first and second electrical signals are mixed to obtain a third electrical signal having a third frequency, where the third frequency is proportional to a temperature of the MEMS resonator. The temperature is determined based on the third frequency. Values of the first and second frequencies can be adjusted based on the determined temperature to compensate for frequency deviations due to temperature deviations. Also described herein are methods and systems for determining the temperature of the dual-output MEMS and for performing frequency compensation, as well as a method of manufacturing the dual-output MEMS.

An oscillator includes: a resonator; an oscillation circuit configured to oscillate the resonator; a first temperature compensation circuit configured to perform a first temperature compensation processing of temperature-compensating for a frequency of a first clock signal generated by oscillation of the resonator by the oscillation circuit; and a second temperature compensation circuit configured to receive the first clock signal subjected to the first temperature compensation processing, and to output a second clock signal subjected to a second temperature compensation processing based on the first clock signal. The first temperature compensation circuit is configured to perform a first-order first temperature compensation processing as the first temperature compensation processing. The second temperature compensation circuit is configured to perform a high-order second temperature compensation processing as the second temperature compensation processing.

An oscillator includes a container, an oscillation element housed in the container, a heating circuit housed in the container, and adapted to control a temperature of the oscillation element, a temperature detection circuit housed in the container, a temperature control circuit housed in the container, and adapted to control the heating circuit based on an output of the temperature detection circuit, at least one connecting wire housed in the container, and electrically connects a ground of the temperature detection circuit and a ground of the temperature control circuit to each other, and a ground external terminal disposed on an outer surface of the container, and electrically connected to the ground of the temperature detection circuit and the ground of the temperature control circuit.

An example resonating structure comprises a substrate, a resonator body, and an anchoring body for anchoring the resonator body to the substrate. The resonator body includes a layer of base material and, deposited on top of the layer of base material, a layer of mismatch material having a mismatch in temperature coefficient of elasticity (TCE) relative to the base material. The base material is doped with a dopant having a concentration chosen so as to minimize a second order temperature coefficient of frequency for the resonator body. The thickness of the layer of the mismatch material is chosen so as to minimize a first order temperature coefficient of frequency for the resonator body.

A slow-clock calibration method, a slow-clock calibration unit, a clock circuit and a mobile communication terminal are provided. The calibration method includes: obtaining a current temperature of the crystal; searching a unique frequency-divide coefficient corresponding to the current temperature from a preset data base; if the coefficient is found in the data base, inputting the unique coefficient into a frequency divider; if the coefficient is not found in the data base, obtaining an actual sleep length of the mobile communication terminal, if the actual sleep length is not equal to a required sleep length, calculating a required frequency-divide coefficient and updating the data base with the required frequency-divide coefficient, and if the actual sleep length of the mobile communication terminal is equal to the required sleep length, updating the data base with a current frequency-divide coefficient. Accordingly, slow-clock calibration is realized with reduced crystal costs.

A stress compensated oscillator circuitry comprises a sensor arrangement for providing a sensor output signal S.sub.Sensor, wherein the sensor output signal S.sub.Sensor is based on an instantaneous stress or strain component a in the semiconductor substrate, a processing arrangement for processing the sensor output signal S.sub.Sensor and providing a control signal S.sub.Control depending on the instantaneous stress or strain component σ in the semiconductor substrate, and an oscillator arrangement for providing an oscillator output signal S.sub.osc having an oscillator frequency f.sub.osc based on the control signal S.sub.Control, wherein the control signal S.sub.Control controls the oscillator output signal S.sub.osc, and wherein the control signal S.sub.Control reduces the influence of the instantaneous stress or strain component σ in the semiconductor substrate onto the oscillator output signal S.sub.osc, so that the oscillator circuitry provides a stress compensated oscillator output signal.

Systems and methods for digital synthesis of an output signal using a frequency generated from a resonator and computing amplitude values that take into account temperature variations and resonant frequency variations resulting from manufacturing variability are described. A direct frequency synthesizer architecture is leveraged on a high Q resonator, such as a film bulk acoustic resonator (FBAR), a spectral multiband resonator (SMR), and a contour mode resonator (CMR) and is used to generate pristine signals.

A time synchronization device adapted for an electronic apparatus, an electronic apparatus, a time synchronization system and a time synchronization method. The time synchronization device includes: a signal generating circuit and a time adjusting circuit. The signal generating circuit includes: a control circuit, configured to generate a frequency control word; and a signal adjusting circuit, configured to receive the frequency control word and an input signal having an initial frequency, and to generate and output an output signal having a target frequency based on the frequency control word and the input signal. The time adjusting circuit is configured to perform a synchronization adjusting operation on a clock signal of the electronic apparatus based on the output signal having the target frequency.