A packaged VCTCXO may include a crystal oscillator configured to output a signal of a particular frequency and a temperature sensor configured to measure an internal temperature of the crystal oscillator. In addition, the packaged VCTCXO may include a microcontroller configured to generate an internal control voltage signal based at least in part on the temperature and an external control voltage received by the packaged VCTCXO. Moreover, the packaged VCTCXO may include a combiner configured to combine an internal control voltage and the external control voltage to generate a control voltage. Further, the control voltage may be supplied to the crystal oscillator to cause the crystal oscillator to generate the signal of the particular frequency.

Provided is a semiconductor integrated circuit including an oscillation circuit configured to output an oscillation signal, a heater configured to heat the oscillation circuit, a temperature sensor configured to detect a temperature of the oscillation circuit, and a nonvolatile memory configured to store temperature correction data. The oscillation circuit controls a frequency of the oscillation signal based on an output signal of the temperature sensor and the temperature correction data.

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.

The present disclosure provides a real-time correction method for an Oven Controlled Crystal (Xtal) Oscillator (OCXO) and an electromagnetic receiver. The real-time correction method for an OCXO includes: performing frequency multiplication on a reference clock signal to generate a first measurement signal and a second measurement signal; identifying a rising edge of each pulse per second on the basis of the first measurement signal to obtain a gate time T; obtaining a frequency of the second measurement signal according to the gate time T; and adjusting a frequency of the reference clock signal at least on the basis that an absolute value of a difference between two adjacent frequencies obtained of the second measurement signal is greater than a standard frequency difference.

Embodiments of the present disclosure provide a server data sending method and a server data sending apparatus. The method can include: acquiring, by a server, crystal oscillator error information and operating rate information of a terminal; setting, by the server, preamble length information according to the crystal oscillator error information and the operating rate information; and sending, by the server, a downlink data frame to the terminal, the downlink data frame comprising a preamble aligned with the preamble length information.

A circuit device includes an oscillation circuit configured to generate an oscillation signal using a resonator, a temperature sensor circuit configured to output temperature detection data, a temperature compensation circuit configured to perform, based on the temperature detection data, temperature compensation on an oscillation frequency of the oscillation signal, a memory configured to store correction data for correcting the temperature detection data to obtain a temperature, and an interface circuit configured to output the temperature detection data and the correction data.

A circuit device includes an oscillation circuit that generates an oscillation signal using a resonator, a temperature detection circuit that outputs temperature detection data, a temperature compensation circuit, and a temperature detection rate control circuit. The temperature compensation circuit performs temperature compensation on an oscillation frequency of the oscillation signal based on the temperature detection data. The temperature detection rate control circuit controls a temperature detection rate at which the temperature detection circuit executes temperature detection. At this time, the temperature detection rate control circuit controls the temperature detection rate based on a variation in the temperature detection data.

A phase locked loop has an oscillator that varies a frequency according to a control signal, a resonance element that resonates at a predetermined resonance frequency and output a signal obtained by shifting a phase of an output signal of the oscillator by 90 degrees at the resonance frequency, a phase detector that detects a phase error between an output signal of the resonance element and an output signal of the oscillator, a feedback controller that controls a frequency of an output signal of the oscillator by proportional control and integral control according to the phase error, and a control signal corrector that corrects the control signal by adding a correction term corresponding to environment information to an output signal of the feedback controller.

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.

A vibration device includes a base including a semiconductor substrate and through electrodes that pass through the portion between first and second surfaces of the semiconductor substrate, and a vibrator fixed to the first surface via an electrically conductive joining member. The following components are placed at the second surface: an oscillation circuit that is electrically coupled to the vibrator via the through electrodes and generates an oscillation signal by causing the vibrator to oscillate, a temperature sensor circuit, a temperature compensation circuit that performs temperature compensation on the oscillation signal, and an output buffer circuit that outputs a clock signal based on the oscillation signal. Dsx1<Dbx1, a distance between the output buffer circuit and one of the through electrodes is Dbx1, a distance between the temperature sensor circuit and the other through electrode is Dsx1.