Abstract: Disclosed are various embodiments of a terahertz wave modulator. The wave modulator can include one or more layers of piezoelectric/ferroelectric single crystal or polycrystalline material. The crystalline material can be configured to resonate when a low-energy external excitation is applied. An incident terahertz waveform can be dynamically controlled when the incident terahertz waveform interacts with the at least one layer of piezoelectric crystalline material while the at least one layer of piezoelectric crystalline material is resonating. The dynamic control of the incident terahertz waveform can be with respect to at least one of a phase shift and an amplitude modulation of the waveform.

Abstract: A high-power transmitter with a fully-integrated phase Iocking capability is disclosed and characterized. Also provided herein is a THz radiator structure based on a return-path gap coupler, which enables the high-power generation of the disclosed transmitter, and a self-feeding oscillator suitable for use with the transmitter.

Abstract: A fast start-up oscillator circuit to reduce a start-up time of a crystal oscillator is presented. The circuit contains a crystal resonator to output a first oscillation signal and a tunable RC oscillator to output a second oscillation signal. A driver is coupled between the tunable RC oscillator and the crystal resonator The driver transfers the second oscillation signal output from the tunable RC oscillator to the crystal resonator. The driver drives the crystal resonator, and a feedback circuit connected between the crystal resonator and the tunable RC oscillator to align a phase of the tunable RC oscillator with a phase of the crystal resonator based on the oscillation signal output by the crystal resonator.

Abstract: The present invention relates to a wireless power transmission apparatus and a method therefor. The present invention provides a wireless power transmission apparatus including: a power transmission module; a first communication module; a second communication module; and a controller for searching out a first wireless power reception device performing wireless power transmission/reception, transmitting a second magnetic field signal of a second frequency band through the power transmission module, sensing a second response signal to the second magnetic field signal through the second communication module, and searching out a second wireless power reception device performing wireless power transmission/reception by means of the second frequency band according to whether the second response signal is received.

Abstract: A crystal controlled oscillator includes a crystal unit, an integrated circuit, and an insulating resin. The crystal unit contains a crystal vibrating piece resonating at a predetermined frequency. The integrated circuit places the crystal unit. The integrated circuit includes an oscillator circuit oscillating the crystal vibrating piece. The insulating resin is formed to cover the crystal unit on the integrated circuit.

Abstract: A digital local oscillator includes a look-up table and oscillator control circuitry. The look-up table contains samples of the digital local oscillator signal. The oscillator control circuitry is configured to select samples from the look-up table based on an accumulated phase value. The oscillator control circuitry is also configured to add a correction value to the accumulated phase value based on a difference of a frequency of the digital local oscillator signal and a desired frequency.

Abstract: A crystal driver circuit for driving a crystal to oscillate at a resonant frequency including an amplifier having an input coupled to an amplifier input node and having an output coupled to an amplifier output node, a current source that provides a core bias current to the amplifier, a first tune capacitor coupled between the amplifier output node and a reference node, and a second tune capacitor coupled between the amplifier input node and the reference node. The first tune capacitor has a first capacitance that is greater than a second capacitance of the second tune capacitor by a capacitance offset that reduces frequency shift during operation. The first and second capacitances have a combined capacitance that achieves an oscillating signal having a target frequency.

Abstract: A digitally controlled oscillator (DCO) may include a transformer, which may contain a secondary winding comprising a first port, a second port, and an array of capacitor units, wherein each capacitor unit includes a first NFET having a gate and a back gate connected to a control signal, and a drain connected to the first port; a second NFET having a gate connected to ground, a back gate connected to the control signal, and a drain connected to the source of the first NFET; and a third NFET having a gate and a back gate connected to the control signal, a drain connected to the source of the second NFET, and a source connected to the second port. The capacitor units may allow fine tuning of the DCO output frequency with a resolution of about 0.3 MHz and a range of about 80 MHz.

Abstract: A voltage-controlled oscillator having a triple-push structure is disclosed. The voltage-controlled oscillator having a triple-push structure may include: a voltage-controlled oscillation part including a multiple number of oscillation circuits configured to output an output signal based on a control voltage, where the multiple oscillation circuits are connected in a triple-push structure; a multiple number of phase shifters connected respectively to the output ends of the oscillation circuits and configured to change a phase of the output signals outputted from the output ends of the oscillation circuits; and an output part configured to output a final output signal by adding the output signals that are outputted with changed phases from the multiple phase shifters.

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q value determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: An atomic clock system includes a magneto-optical trap (MOT) system that traps alkali metal atoms in a cell during a trapping stage of each of sequential coherent population trapping (CPT) cycles. The system also includes an interrogation system that generates an optical difference beam comprising a first optical beam having a first frequency and a second optical beam having a second frequency different from the first frequency. The interrogation system includes a direction controller that periodically alternates a direction of the optical difference beam through the cell during a CPT interrogation stage of each of the sequential clock measurement cycles to drive CPT interrogation of the trapped alkali metal atoms. The system also includes an oscillator system that adjusts a frequency of a local oscillator based on an optical response of the CPT interrogated alkali metal atoms during a state readout stage in each of the sequential clock measurement cycles.

Abstract: Present invention relate to a wideband signal source. The wideband signal source comprises a voltage controlled oscillator (VCO), a first buffer and a programmable frequency extender. The VCO outputs a signal with at least N:1 frequency tuning ratio, with N being an integer or a non-integer number larger than 1. The frequency extender receives the signal via the buffer to generate a final output, which has a wider frequency band than the signal. The buffer isolates the final output from interfering VCO for VCO operation stability. The frequency extender comprises at least a 1/N frequency divider, which matches the N:1 frequency tuning ratio of the signal, such that the final output has a gapless frequency band wider than the VCO output signal.

Abstract: The present invention relates to a wireless power transmission apparatus and a method therefor. The present invention provides a wireless power transmission apparatus including: a power transmission module; a first communication module; a second communication module; and a controller for searching out a first wireless power reception device performing wireless power transmission/reception, transmitting a second magnetic field signal of a second frequency band through the power transmission module, sensing a second response signal to the second magnetic field signal through the second communication module, and searching out a second wireless power reception device performing wireless power transmission/reception by means of the second frequency band according to whether the second response signal is received.

Abstract: An oscillator circuit is disclosed. The oscillator circuit includes: oscillator transistors including gates; adjustment transistors coupled to the gates; a differential output coupled to the oscillator transistors; a switch configured to set an oscillation frequency of the differential output by driving: a first current including a first portion of a main current through at least one of the oscillator transistors; and a second current including a second portion of the main current through at least one of the adjustment transistors; a first set of auxiliary current sources configured to adjust a temperature coefficient of the oscillator circuit by driving a first set of auxiliary currents through the oscillator transistors; and a second set of auxiliary current sources configured to maintain the oscillation frequency of the differential output by driving, in response to driving the first set of auxiliary currents, a second set of auxiliary currents though the adjustment transistors.

Abstract: Aspects of methods and systems for high frequency signal selection are provided. The system for high frequency signal selection comprises a first driver and a second driver. The first driver is able to receive a first high frequency input, and the second driver is able to receive a second high frequency input. The output of the first driver is operably coupled, via a first inductive element, to a first resistive load and a first buffer, and the second driver is operably coupled, via a second inductive element, to the output of the first driver. One or both of the first high frequency input and the second high frequency input may be transferred to the first buffer by selectively enabling a current to one or both of the first driver and the second driver, respectively.

Abstract: A circuit device includes a first oscillation circuit, a second oscillation circuit, a clock signal output circuit adapted to output a clock signal based on an output signal of the first oscillation circuit, and an output control circuit adapted to perform output control of the clock signal output circuit. The output control circuit includes a counter circuit adapted to perform a counting process based on an output signal of the second oscillation circuit, and the counter circuit outputs an output enable signal of the clock signal to the clock signal output circuit based on a result of the counting process.

Abstract: Wireless charging systems, and methods of use thereof, are disclosed herein. As an example, a method includes: receiving, by a radio of a transmitter, a communication signal from a wireless-power-receiving device, the communication signal containing location data indicating a location of the wireless-power-receiving device. The method further includes, in response determining that the location of the wireless-power-receiving device is within a predetermined range from the transmitter: (i) generating sound waves from a sound wave integrated circuit of the transmitter and (ii) transmitting the sound waves through a plurality of transducer elements to the location of the wireless-power-receiving device, wherein the sound waves are transmitted so that they converge constructively to form a controlled constructive interference pattern in three-dimensional (3-D) space at the location of the wireless-power-receiving device.

Abstract: In a sine-wave multiplier, signal components included in an output signal Qu1 and corresponding to the product of a third-order harmonic component of a first square wave W1 and an input signal Vi and the product of a fifth-order harmonic component of the first square wave W1 and the input signal Vi are offset by a signal component included in an output signal Qu2 and corresponding to the product of a fundamental component of a second square wave W2 and the input signal Vi and a signal component included in an output signal Qu3 and corresponding to the product of a fundamental component of a second square wave W3 and the input signal Vi.

Abstract: A dual-mode oscillator and a multi-phase oscillator includes a mode switching circuit to switch between two operating modes and obtain oscillation signals having two different bands. The dual-mode oscillator also includes two transformer-coupled oscillators and a step-up transformer in the transformer-coupled oscillators where the step-up transformer multiplies a drain voltage swing of a first MOS transistor and then injects a voltage signal to a gate of a second MOS transistor to obtain a larger gate voltage swing without increasing a supply voltage of the oscillator. The dual-mode oscillators are connected through multi-phase coupled circuits to form a Mobius loop.

Abstract: A signal source with a wireless frequency reference. A signal loop includes an amplifier and a coupler. The magnitude of the loop gain in the signal loop is substantially equal to 1 at a steady-state amplitude of a signal at a fundamental frequency. A reference oscillator is coupled to the loop through the coupler, via a wireless link, and provides phase stabilization. The loop may include a nonlinear transmission line, to generate a comb output spectrum.