Abstract: The frequency stability of an optical local oscillator is improved by locking a laser to a silicon Fabry-Perot cavity operating at a temperature near 124 K, where the coefficient of thermal expansion of silicon is near zero. The cavity is mounted inside a cryostat housed in a temperature-stabilized vacuum system that is surrounded by an isolating enclosure and supported by an active vibration platform. Laser light is steered with a superpolished mirror toward a superpolished focusing optic that couples the laser light into the cavity. Light reflected from the cavity is used to stabilize the laser via the Pound-Drever-Hall technique, while light transmitted through the cavity is used to stabilize the laser power. A resonant transimpedance amplifier allows the laser power to be reduced, which reduces heating of the cavity caused by residual absorption of the light.

Abstract: An oscillator circuit comprises a crystal oscillator arranged to generate an oscillation signal, a bias current generator arranged to supply a bias current to the crystal oscillator, and a feedback stage arranged to generate a feedback signal in response to an amplitude of the oscillation signal reaching an amplitude threshold. The bias current generator is arranged to: in response to a supply of power to the oscillator circuit being switched on, generate the bias current at an increasing level commencing from a first level; in response to the feedback signal, terminate the increasing; and during subsequent oscillation of the crystal oscillator, supply the bias current at a second level dependent on a final level of the bias current reached when the increasing is terminated.

Abstract: In an electrical traction drive for a vehicle comprising at least two individual wheel drives that are to be controlled independently of each other, the drives are able to be operated redundantly in order for an emergency operating function to be implemented.

Abstract: A non-contact self-injection-locked vital sign sensor is disclosed, which includes transmitting antenna, receiving antenna, self-injection-locked integrated circuit and demodulator. The self-injection-locked integrated circuit includes voltage-controlled oscillator, mixer, two amplifiers and harmonic-frequency power combiner. A frequency-multiplied signal is produced by amplifiers and harmonic-frequency power combiner then transmitted to a living body by transmitting antenna. A frequency-divided signal is produced by voltage-controlled oscillator and mixer then transmitted to voltage-controlled oscillator, then a frequency- and amplitude-modulated signal is produced by the voltage-controlled oscillator then transmitted to demodulator to produce a vital sign. So as to detect vital sign with a higher frequency to increase measurement sensitivity by using a low-cost integrated circuit process.

Abstract: An electronic device includes a phase locked loop configured to perform a two-point modulation operation on a data signal by using first and second modulation paths, and the phase locked loop is configured to generate, based on a differential value of a first phase error signal generated in the first modulation path, a gain for adjusting a frequency variation of the data signal through the second modulation path so as to match with the frequency variation of the data signal through the first modulation path.

Abstract: An accurate replica oscillator-based frequency tracking loop (FTL) is provided. The replica oscillator used in the FTL can be at a lower frequency and therefore can consume much lower power compared to a main oscillator, such as an injection locked oscillator (ILO). The proposed FTL accurately sets the free running frequency of an ILO across process, voltage and temperature (PVT). Techniques are also provided to compensate the gain and offset error between the replica oscillator and the ILO.

Abstract: A stress-based aging monitor circuit includes a reference ring oscillator circuit and a stressed ring oscillator circuit that each include transistors like the transistors in a circuit to be monitored. Transistors in the stressed ring oscillator circuit receive a negative gate to source voltage bias while the reference ring oscillator is protected from stress. To measure performance degradation due to stress-based aging, the switching frequencies of the reference ring oscillator circuit and the stressed ring oscillator circuit are compared. The reference ring oscillator and the stressed ring oscillator include stress-enhanced inverter circuits configured to amplify stress-based aging effects to increase sensitivity to the performance degradation caused by stress-based aging. Increased sensitivity increases the precision (e.g.

Abstract: A battery-less Internet of things (IoT) tag integrated with a proximity sensor is disclosed. The battery-less IoT tag includes: a transmit antenna designed to have an inductive element; an integrated circuit having a capacitive element; and an energy harvester coupled to a capacitor, wherein the capacitor is an on-die capacitor and the energy harvester is configured to harvest energy from ambient signals, wherein the inductive element and the capacitive element form the proximity sensor oscillating at a local oscillator (LO) frequency, and wherein a frequency offset from the LO frequency is indicative of a detection of a nearby object.

Abstract: Techniques are described that enables controlling the TNULL characteristic of a self-compensated oscillator by controlling the magnitude and direction of the frequency deviation versus temperature, and thus, compensating the frequency deviation.

Abstract: The disclosure relates to a radio frequency oscillator. The radio frequency oscillator includes a resonator circuit being resonant at an excitation of the resonator circuit in a differential mode and at an excitation of the resonator circuit in a common mode. The resonator circuit has a differential mode resonance frequency at the excitation in the differential mode, and the resonator circuit has a common mode resonance frequency at the excitation in the common mode. A first excitation circuit is configured to excite the resonator circuit in the differential mode to obtain a differential mode oscillator signal oscillating at the differential mode resonance frequency, and a second excitation circuit is configured to excite the resonator circuit in the common mode to obtain a common mode oscillator signal oscillating at the common mode resonance frequency.

Abstract: A power inverter, such as a synchronous buck power inverter, that is configured with a high frequency switching control having a (PWM) controller and sensing circuit. Controller provides a low frequency oscillating wave to effect switching control on a synchronous-buck circuit portion that includes a plurality of switches to invert every half cycle of the frequency provided by controller. The inverting process thus creates a positive and negative transition of the oscillating wave signal. A low frequency switching stage includes a further plurality of switches configured to operate as zero voltage switching (ZVS) and zero current switching (ZCS) drives Charge on an output capacitor is discharged to zero on every zero crossing of low frequency switching stage and advantageously discharges energy every half cycle. During this discharge of energy, the zero crossing distortion in the low frequency sine wave is greatly reduced.

Abstract: An integrated circuit has an oscillator circuit having an on-chip oscillator, a digital phase locked loop and a sensor. A frequency of an output signal from the oscillator circuit is adjustable. The digital phase locked loop receives the output signal from the oscillator circuit at an input and a synchronization signal based on an output signal from an external precision oscillator in the form of a crystal oscillator or MEMS oscillator at an external interface and generates a control signal in order to synchronize the frequency of the oscillator circuit with the frequency of the external crystal oscillator. The sensor is designed to measure at least one environmental parameter, wherein the digital phase locked loop is designed to take into account the at least one measured environmental parameter when generating the control signal.

Abstract: The present disclosure relates to a multi-mode voltage controlled oscillation device and a wireless transceiver. The multi-mode voltage controlled oscillation device includes an oscillation core circuit and at least four resonance circuits. Each of the resonance circuits includes two input ends and one power supply end. The two input ends of each of the resonance circuits are respectively connected to an output end of the oscillation core circuit, and the power supply end of each of the resonance circuits is configured to be connected to a power supply. The multi-mode voltage controlled oscillation device provided by the present disclosure is formed by connecting the oscillation core circuit with each resonance circuit and connecting the resonance circuits with each other, with a simple structure, a tight connection, and a small area.

Abstract: An oscillator calibration circuit is presented. The oscillator calibration includes a first frequency locking circuit (FLC) coupled to a first oscillator, wherein the first FLC calibrates the frequency of the first oscillator using an over-the-air reference signal, wherein the first FLC calibrates the first oscillator prior to a data transmission session and remains free running during the data transmission session; and a second FLC coupled to a second oscillator, wherein the second FLC calibrates the frequency of the second oscillator using the over-the-air reference signal, wherein the second FLC calibrates the second oscillator immediately prior to a data transmission session and remains free running during the data transmission session.

Abstract: The present invention provides an oscillator circuit and a semiconductor integrated circuit, which can suppress the upper limit of the frequency of a clock signal due to an error of the constant current circuit. The oscillator circuit of the present invention includes a constant current circuit, an oscillator, and a current limiting circuit. The constant current circuit generates a first output current according to a supply voltage. The current limiting circuit receives the first output current and generates a second output current, and establishes an upper limit for the second output current when the supply voltage drops below a lower limit of a guaranteed operational range of the constant current circuit. The oscillator generates a clock signal according to the second output current. By establishing the upper limit for the second output current, the upper limit of the frequency of the clock signal can be suppressed.

Abstract: An oscillator includes a resonator, sustaining circuit and detector circuit. The sustaining circuit receives a sense signal indicative of mechanically resonant motion of the resonator generates an amplified output signal in response. The detector circuit asserts, at a predetermined phase of the amplified output signal, one or more control signals that enable an offset-reducing operation with respect to the sustaining amplifier circuit.

Abstract: A resonator circuit includes a transformer comprising a primary winding and a secondary winding. The primary winding is inductively coupled with the secondary winding. A primary capacitor is connected to the primary winding. The primary capacitor and the primary winding form a primary circuit. A secondary capacitor is connected to the secondary winding. The secondary capacitor and the secondary winding form a secondary circuit. The resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode. The resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode. The common mode resonance frequency is different from the differential mode resonance frequency.

Abstract: Systems and methods are provided for compensating for mechanical acceleration at a reference oscillator. A reference oscillator provides an oscillator output signal and an accelerometer on a same platform as the reference oscillator, such that mechanical acceleration at the reference oscillator is detected at the accelerometer to produce a measured acceleration. A filter assembly, having an associated set of filter weights, receives the measured acceleration from the accelerometer and provides a tuning control signal responsive to the measured acceleration to a frequency reference associated with the system. An adaptive weighting component receives the oscillator output signal of the reference oscillator and an external signal that is provided from a source external to the platform and adjusts the set of filter weights for the filter assembly based on a comparison of the external signal and the oscillator output signal.

Abstract: A differential crystal oscillator includes a source follower configured to receive an oscillatory signal and output a regenerated signal; a resonant network having a crystal and configured to terminate the oscillatory signal and determine an oscillation frequency of the oscillatory signal; a regenerative network configured to regenerate the regenerated signal; and a capacitive feedback network configured to provide a feedback from the regenerated signal to the oscillatory signal.

Abstract: A small-size high-power terahertz oscillator achieves a stable oscillation in a terahertz frequency band even at room temperature. The high-power terahertz oscillator has a structure in which a bow-tie antenna is disposed on a substrate, a cavity resonator, which includes two cavities, is disposed at a power supply portion of the bow-tie antenna, and a resonant tunneling diode (RTD) is disposed along a bottom of a wall of the cavity resonator, which defines the two cavities, and stably oscillates waves in the terahertz frequency band at room temperature by using the RTD, the bow-tie antenna and the cavity resonator.