Systems and methods for precision phase noise measurements of radio frequency (RF) oscillators are provided. An RF signal under test can be modulated on a continuous wave (cw) laser carrier frequency via generation of modulation sidebands using an appropriate modulator. A photonic delay line can be implemented as a self-heterodyne detection system for the phase noise, allowing for photonic down-conversion of the phase noise measurement to direct current (DC). The self-heterodyne detection system allows detection outside of any 1/f noise issues. Ultra-low phase noise detection for RF frequencies in a range from below 1 GHz to beyond 100 GHz is enabled with a low noise floor in the whole frequency range. Higher-order modulation sidebands can further reduce the noise floor of the system. Ultra-low noise RF (microwave) output can be generated. The RF signal under test can be generated by a dielectric resonance oscillator or opto-electronic oscillator.

A power transmission apparatus that can wirelessly transmit power to a power reception apparatus via a power transmission coil and communicate with the power reception apparatus determines presence/absence of an object different from the power reception apparatus based on a Q factor of the power transmission coil measured in a phase for performing power transmission. The power transmission apparatus controls whether to execute the determination of presence/absence of the object different from the power reception apparatus based on measurement of the Q factor of the power transmission coil, based on information received from the power reception apparatus through communication that represents whether the power reception apparatus can execute predetermined processing associated with the determination of presence/absence of the object different from the power reception apparatus based on the measurement of the Q factor of the power transmission coil.

Embodiments of the present disclosure include a microcontroller with a frequency test circuit, a device-under-test (DUT) input, and a calculation engine circuit. The calculation engine circuit is configured to compare a measured frequency from the frequency test circuit measured from the DUT input to a reference frequency stored in memory, and, based on the comparison, adjust frequency of the DUT generating the DUT input.

A power transmitting apparatus measures a Q factor of a power transmitting unit that performs wireless power transfer to a power receiving apparatus, and determines presence/absence of an object different from the power receiving apparatus based on the Q factor. The power transmitting apparatus obtains a first index value regarding a predetermined physical amount different from the Q factor after measurement of the Q factor, obtains a second index value regarding the predetermined physical amount before wireless power transfer to the power receiving apparatus starts after the it is determined in the above determination that an object different from the power receiving apparatus does not exist; and determines presence/absence of an object different from the power receiving apparatus based on the first index value and the second index value.

A test system (and methodology) suitable for testing a resonant sensor circuit configured to drive a sensor resonator with a negative resistance. Example embodiments include a test sensor resonator setup configured to simulate a sensor resonator with a selectable loss factor Rs, and includes, in a single-ended configuration, a first oscillator signal source that generates a first oscillation signal, coupled to a first controllable resistor that provides a controlled resistance R1 that simulates a selectable sensor resonator loss factor Rs, which together generate a first oscillation voltage signal based on the controlled resistance R1. A DUT resonant sensor circuit is coupled to receive the first oscillation voltage signal at a first input, and generate a negative resistance Ra that substantially counterbalances the resistance R1 (corresponding to sustained oscillation). A differential configuration includes first and second oscillator signal sources, coupled to first and second controllable resistors R1 and R2.

A monitoring circuit for a high frequency signal includes: a phase locked loop configured to generate a divided output signal with respect to an input signal based on a plurality of dividers; a plurality of dividing monitoring circuits configured to receive dividing input signals and dividing output signals respectively corresponding to the plurality of dividers, and output dividing error signals; and a jitter monitoring circuit configured to output a jitter error signal.

A measurement system includes a narrowband receiver configured to receive an input signal with an initial bandwidth. The narrowband receiver includes at least one local oscillator configured to provide a local oscillator signal having a center frequency and at least one signal mixer configured to mix the input signal and the local oscillator signal to obtain a mixed signal including image portions. The mixed signal has a respective center frequency in view of the local oscillator signal mixed therein. The narrowband receiver is configured to process two or more mixed signals, thereby obtaining two or more captured signals for different center frequencies of the local oscillator signal. The two or more captured signals have a limited bandwidth compared to the initial bandwidth. The narrowband receiver is configured to combine the two or more captured signals in order to obtain a processed signal without image portions.

A BIST system and method for a crystal oscillator amplifier including current mirror circuitry, an ADC, a DAC, and test control circuitry. The amplifier includes a current source, a base transistor and a feedback resistor. The ADC converts a self-bias voltage on an input node into a digital bias code during a normal mode when the current source is coupled to the base transistor. During phases of a test mode, the base transistor is coupled instead to the mirror circuitry, which mirrors current through the base transistor into a test resistor. The digital bias code is converted into upper and lower digital bias codes using a delta value, which are converted by the DAC into corresponding bias voltages driven onto the input node during respective phases of the test mode. The ADC converts corresponding test voltages on the test resistor into test codes used to estimate the amplifier transconductance.

The present disclosure provides a measurement application device calibration unit, comprising a coupling element comprising a first connection and a second connection for coupling the coupling element into a signal measurement path, and a third connection, wherein the coupling element is configured to at least one of couple out a signal from the signal measurement path into the third connection, and couple in a signal from the third connection into the signal measurement path, and comprising a signal processing device that is coupled to the third connection of the coupling element and that is configured to receive the predetermined calibration signal when the coupling element couples out a signal from the signal measurement path into the third connection, and to generate a predetermined calibration signal when the coupling element couples in a signal from the third connection into the signal measurement path.

Modulation testing separately enables slices of an analog varactor array of an LC oscillator. For each enabled slice, a reference voltage supplying a resistor ladder is set to a plurality of different reference voltage values. Resistor ladder voltages generated for the different reference voltage values are supplied to the enabled slice and a control voltage coupled to the enabled slice is swept for each of the reference voltage values. Respective frequencies of an oscillator signal coupled to an output of the LC oscillator are measured for each enabled slice for each combination of the reference voltage values and the control voltage values. The linearity of LC oscillator gain is determined for each of the reference voltage values for each slice based on the respective frequencies and the control voltage values. Passing/failing the modulation testing is based on the linearity of the LC oscillator gain.