Abstract: A magneto-inductive DC magnetometer is provided that is operable to output fluxgate quality measurements in a low mass, volume, power and cost package. The magnetometer enables constellation-class missions not only due to its low-resource requirements, but also due to its potential for commercial integrated circuit fabrication. In addition, the magnetometer will be part of a ground-based Space Weather Underground Citizen Science instrument package that enables dense arrays of space weather-relevant observations at mid-latitudes. The magneto-inductive operating principle is based on a simple resistance-inductor (RL) circuit and involves measurement of the time it takes to charge and discharge the inductor between an upper and lower threshold by means of a Schmitt trigger oscillator. This time is proportional to the inductance that in turn is proportional to the field strength.

Abstract: An electromobility charge testing system and a charge testing method for generating and exchanging measurement data and/or a charging model of a charging operation of an electric vehicle and/or charging station, and for testing the communication capability and/or chargeability, includes: at least one measuring device for providing the measurement data of the charging operation of the electric vehicle and/or charging station, wherein the measurement data is subdividable into action data and reaction data; at least one modeling device for creating a charging model of the charging operation; at least one server device for storage and provision of an exchange possibility for the measurement data and/or charging model; and at least one emulation device for downloading the measurement data and/or the charging model by playing back the selected measurement data subdividable into action data and reaction data and/or the correspondingly generated charging model.

Abstract: Various embodiments of the present invention relate to a method for detecting and controlling a battery status by using a sensor, and an electronic device using the same, the electronic device comprising: a housing; an accommodation part arranged inside the housing and including at least one gas sensor; a battery arranged inside the housing; a memory for storing information, acquired by the at least one gas sensor, on gas leaked from the battery and operation control information of the electronic device; and a processor electrically connected to the memory, wherein the processor is configured to acquire a detection signal of gas leaked from the battery by using the at least one gas sensor, and control the operation of at least a part of the electronic device and/or charging characteristics of the battery when the acquired gas detection signal exceeds a predetermined threshold value, so as to detect, in real time, a gas leakage of the battery occurring because of the exposure of the electronic device to high t

Abstract: Methods and apparatus for determining biological effects of environmental sounds are disclosed. An example apparatus includes a sound characteristic analyzer to identify a sound event based on audio data in an environment. The example apparatus includes a physiological data analyzer to identify a physiological event based on physiological response data collected from a user exposed to the sound event in the environment. The example apparatus includes a correlation identifier to identify a correlation between the sound event and the physiological event and a report generator to generate a report based on the correlation.

Abstract: The present invention is a system and method for providing a charge detector that utilizes small feedback capacitors in a low-noise, high-gain, system that combines a differential topology in a solid-state amplifier implemented in a complementary metal-oxide semiconductor (CMOS) process with active reset, thereby achieving high dynamic range and robust operations. A custom optoelectronic system is used to measure gain, and while operating at a sampling frequency of 10 kHz, the active reset extends the dynamic range of the charge detector.

Abstract: In a general aspect, an integrated microwave circuit is disclosed for processing quantum information. The integrated microwave circuit includes a substrate having a first surface and a second surface opposite the first surface. The substrate is formed of a silicon oxide material having a loss tangent no greater than 1×10?5 at cryogenic temperatures at or below 120 K. The integrated microwave circuit also includes qubit circuitry disposed on the first surface that includes a Josephson junction. A ground plane is disposed on the first surface or the second surface. In some variations, the silicon oxide material is fused silica. In other variations, the silicon oxide material is crystalline quartz.

Abstract: A test system for testing an integrated circuit package is provided. The test system may include a test board on which a package under test can be mounted, a test box for gathering desired measurements on the package under test, and a test host for automatically controlling the test box during testing. The test box may be coupled to row multiplexing circuitry and column multiplexing circuitry for selectively addressing one or more daisy-chained nets in the package under test. The test box may also be coupled to a source measurement unit (SMU) component that provides current source signals to the package under test and to a digital multimeter (DMM) component that provides voltage sense signals to the package under test. Arranged in this way, the test system can be configured to perform automated I-V curve tracing, resistance measurements, open/short circuit detection, and monitoring of other package-level manufacturing defects.

Abstract: A technique relates to operating a multimode Josephson parametric converter as a multimode quantum limited amplifier. The multimode Josephson parametric converter receives multiple quantum signals in parallel at different resonance frequencies. The multimode Josephson parametric converter amplifies simultaneously the multiple quantum signals, according to pump signals applied to the multimode Josephson parametric converter. The multiple quantum signals having been amplified at the different resonance frequencies are reflected, according to the pump signals.

Abstract: An EMC test bench, includes an item of equipment under test to be loaded on board an aircraft, the item of equipment being subjected to EMC tests and delivering ARINC electrical interfaces as inputs and as output; an electrical interfaces device representative of an item of anti-lightning equipment and including an ARINC signals acquisition and/or generation card connected to the ARINC inputs and outputs of the item of equipment under test; a command and control rack for analyzing control signals originating from the electrical interfaces device including the ARINC signals acquisition and/or generation card, and a signals conversion system for protecting the command and control rack connected between the command and control rack and the electrical interfaces device.

Abstract: A system for controlling the aeration of a grain bin storage device. The system comprises a grain bin storage device, a ventilation fan, a variable fan drive motor, and a controller configured to receive user input and grain bin storage device parameters. The system controls operation of the ventilation fan at various speeds to maintain a desired volumetric flow rate per bushel of grain. The controller monitors the static pressure within the grain bin storage device and adjusts the speed of the ventilation fan based on an optimal static pressure derived from the user input and grain bin storage device parameters.

Abstract: Target sensor comprising: sensor probe having a resonance frequency that changes as the separation of the sensor probe and a target changes. Oscillator arranged to apply a radio frequency (RF) signal to the sensor probe, the oscillator having: control circuitry configured to regulate the frequency of the RF signal applied to the sensor probe to below the resonance frequency of the sensor probe. Detector arranged to detect an electrical characteristic of the oscillator that varies with the impedance of the sensor probe indicating an interaction of the sensor probe with the target.

Abstract: A sensor includes a coil suspended in a magnetic field, an optical detector to detect displacement of the coil in response to a stimulus, and a feedback circuit coupled to the optical detector and to the coil to drive the coil. The sensor also includes a damping circuit coupled in parallel with the coil.

Abstract: A method for reducing a delay, between a transition of a transmission of a metal detector and a process of a receive signal received by a receive coil of the metal detector, due to a critically damped time constant of the receive coil, including: introducing a negative capacitance into the receive coil to reduce the critically damped time constant.

Abstract: Embodiments relate to systems and methods for selecting circuit element values for a hybrid active power filter operating over a variable frequency. In aspects, a hybrid active power filter (HAPF) circuit can eliminate current harmonics present in an AC power source which are caused by an AC load network.—In implementations, the AC voltage source—may be a source having a variable frequency range, for instance 360-800 Hz. Since the source voltage can encompass a significant frequency range, a simple determination of the correct or desirable values of capacitive and inductive elements in the filtering section of the HAPF may not be possible. According to aspects, analytic techniques are provided which allow the values of those circuit elements to be derived from impedance and other circuit values to provide satisfactory suppression of identified harmonics, which can include the 5th, 7th, 11th, 13th, 17th, 19th, 23rd, 25th harmonics in the output voltage.

Abstract: The present invention relates to a method for calibrating a receiver device or a stimulus-response system comprising a receiver device. The method comprises the steps of generating at least one tone with a repeatable and known phase value, said at least one tone being stepped in frequency to cover a given set of calibration tones, and applying the at least one tone to the receiver device or to the stimulus-response system, generating a reference signal, which is phase-coherent with the at least one tone, to measure in a phase-coherent way with the receiver device or with the stimulus-response system the at least one tone, measuring at least the phase of the at least one tone using the receiver device or the stimulus-response system, determining at least phase-related information for calibration coefficients at the given set of calibration tones by calculating a phase deviation of the measured phase from the known phase value of the at least one tone.

Abstract: An auxiliary test apparatus for electromagnetic compatibility includes two substantially parallel side plates and a dividing plate substantially perpendicularly connected between centerlines of the side plates. A through hole is defined in a center portion of the dividing plate. Top and bottom surfaces of the dividing plate and the inner surfaces of the side plates are covered by conductive foam.

Abstract: An electromagnetic compatibility testing system includes an anechoic chamber. The anechoic chamber includes a testing table, an antenna, an amplifier, and a receiver. A test sample is placed on the testing table. The antenna receives electromagnetic signals emitted by the test sample and transmits the electromagnetic signals to the amplifier via a coaxial cable. The receiver is connected to the amplifier via the coaxial cable analyzing the electromagnetic signals amplified by the amplifier.

Abstract: A method for multivariable measurements using a single-chip impedance analyzer includes providing a sensor, exposing the sensor to an environmental parameter, determining a complex impedance of the sensor over a measured spectral frequency range of the sensor, and monitoring at least three spectral parameters of the sensor.

Abstract: An arc flash validation unit may generate stimulus to be received by an arc flash detection unit (AFDU) and observe the response of the AFDU thereto. The response of the AFDU to the stimulus may allow for validation of the AFDU (e.g., validation that the AFDU is operating as expected). In addition, the arc flash validation unit may determine the response time of the AFDU. Different types of stimulus may be provided to the AFDU, including electro-optical (EO) stimulus (e.g., visible light), current stimulus, and the like. Results of the validation may be displayed on a human-machine interface, which may display an estimate of the total energy that would be released in an actual arc flash event. The estimate may be used to define appropriate safety parameters for the equipment monitored by the AFDU.

Abstract: A test system may be provided in which devices under test are tested using radio-frequency test stations. A test station may include a test host, a test unit coupled to the test host, and a shielded enclosure. The shielded enclosure may contain a test antenna coupled to the test unit via a radio-frequency cable. A computer-controlled loading arm may be used to place a device under test on a positioner within the test enclosure. The test enclosure may have an enclosure door that is opened and closed using a computer-controlled pneumatic cylinder. When the enclosure door is closed, a portion of the enclosure door may actuate one or more levers on the positioner, which may in turn actuate one or more positioning arms to press the device under test against one or more guide surfaces on the positioner, thereby precisely positioning the device under test within the test enclosure.

Abstract: Methods and apparatuses for evaluating a material are described. Embodiments typically involve use of an impedance measurement sensor to measure the impedance of a sample of the material under at least two different states of illumination. The states of illumination may include (a) substantially no optical stimulation, (b) substantial optical stimulation, (c) optical stimulation at a first wavelength of light, (d) optical stimulation at a second wavelength of light, (e) a first level of light intensity, and (f) a second level of light intensity. Typically a difference in impedance between the impedance of the sample at the two states of illumination is measured to determine a characteristic of the material.

Abstract: Systems, methods, and apparatus relating to electric vehicle (EV) charger testing systems are disclosed and claimed herein. Exemplary systems comprise an EV charger connection interface having communication and power connections complying with one or more EV charging protocols, an electrical load module connected to power connections, and charging protocol compliance signal generators connected to the charger connection interface for simulation of a connection between an EV and an EV charger. Testing systems may be used to monitor, record, and profile the output of an EV charger and determine compliance of the output with one or more EV charging protocols. Additionally, methods related to testing and analyzing charge output of an EV charger are disclosed, including determining which of multiple charging protocols to use while testing the charger.

Abstract: A fuel cell system according to the present invention is characterized by comprising a measurement unit which measures an impedance of a fuel cell in a predetermined frequency region, and a regulation unit which regulates an amount of a gas to be supplied to the fuel cell based on a measured value of the impedance in the predetermined frequency region. According to such a constitution, the impedance of the fuel cell in the predetermined frequency region (e.g., a low frequency region) is measured, and the amount of the gas (e.g., an amount of an oxidizing gas) to be supplied to the fuel cell is regulated based on this measured value of the impedance. Here, since the impedance of the fuel cell in the predetermined frequency region largely differs with a fuel supply state (see FIG. 2), the amount of the gas to be supplied to the fuel cell can be regulated based on the measured value of the impedance to realize a highly efficient and stable operation.

Abstract: The present invention relates to a tester, its use and a method for testing signal lines of a flight control system for a trimmable horizontal stabilizer (THS) motor of an aircraft. The tester comprises at least one test-relay (52, 54) to be connected with a relay socket of the flight control system, when the signal lines of the flight control system are to be tested, and at least one indicator (60, 70, 80, 90) being electrically connected with the at least one test-relay (52, 54) for indicating whether a voltage being applied to the test-relay (52, 54) is equal to or larger than a predetermined voltage. The method according to the invention comprises the steps of connecting at least one test-relay (52, 54) of a tester (1), in place of the original relay, with the relay socket of the flight control system, applying a voltage to the at least one test-relay (52, 54) and determining whether a voltage being applied to the at least one test-relay (52, 54) is equal to or larger than a predetermined voltage.

Abstract: A test fixture for performing RF testing. The test fixture includes a base plate configured to support an electronic device. The base plate defines a grid of grooves. The base plate further defines a cut-out configured to receiving an antenna in one or more positions. The test fixture further includes markers indicating positioning of the electronic device on the base plate.

Abstract: An evaluation device 20 comprises a circuit element comprising respective pairs of inputs and outputs including several capacitances 25a-25c and resistances 26a-26d, one end of each being connected to both ends of the capacitances 25a-25c, wherein a resistance value of a signal input side is generally equal to that of a signal output side. The evaluation device 20 is further provided with a connecting terminal with an output device 10 for outputting signals to a device to be evaluated 30 on the signal input side, and is provided with a connecting terminal with the device to be evaluated 30 on the signal output side.

Abstract: There is provided a fuel cell system in which a constantly accurate impedance measurement is made possible regardless of a response characteristic of the voltage converting device. A superimposed signal analysis section analyzes an impedance measuring signal after passing through a DC/DC converter to thereby notify a superimposed signal amplitude control section of an analysis result. A superimposed signal amplitude control section controls an amplitude value of the impedance measuring signal generated by a superimposed signal generating section based on the result notified from the superimposed signal analysis section.

Abstract: There is provided a fuel cell system in which a constantly accurate impedance measurement is made possible regardless of a response characteristic of the voltage converting device. A superimposed signal analysis section analyzes an impedance measuring signal after passing through a DC/DC converter to thereby notify a superimposed signal amplitude control section of an analysis result. A superimposed signal amplitude control section controls an amplitude value of the impedance measuring signal generated by a superimposed signal generating section based on the result notified from the superimposed signal analysis section.

Abstract: A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.

Abstract: The invention relates to a method and system and microchip for determining impedance of a variable impedance component. The method comprises tuning a tunable oscillator over a predefined tuning range, the tunable oscillator having the variable impedance component coupled as a load thereof. The frequency response of the tunable oscillator is measured as a function of said tuning. Finally, the measured frequency response is analyzed for determining the impedance of the variable impedance component. The invention makes possible to manufacture smaller and simpler monolithic sensor microchips.

Abstract: A method for converting a sensor capacitance under parasitic capacitance conditions and a capacitance-to-voltage (CV) converter circuit for converting a sensor capacitance under parasitic capacitance conditions are provided. The method comprises the step of using a two stage operational amplifier (op-amp) in non-unity-gain configuration, wherein the two stage op-amp is chosen to be unstable in unity-gain configuration for reducing power consumption.

Abstract: There is provided a fuel cell system in which a constantly accurate impedance measurement is made possible regardless of a response characteristic of the voltage converting device. A superimposed signal analysis section analyzes an impedance measuring signal after passing through a DC/DC converter to thereby notify a superimposed signal amplitude control section of an analysis result. A superimposed signal amplitude control section controls an amplitude value of the impedance measuring signal generated by a superimposed signal generating section based on the result notified from the superimposed signal analysis section.

Abstract: In one embodiment, the present invention includes a test signal generator capable of producing an impedance test signal comprising of a sine wave having a known frequency. The test signal generator may include a crystal oscillator, a counter, and a lookup table. The lookup table output is applied to a digital to analog converter and is then low pass filtered using a conventional analog filter to produce a sine wave of a known frequency and voltage amplitude. The test signal flows through the electrode and combines with an electrophysiological signal to form a combined signal. A signal processor is used to isolate the combined signal into the test signal component and the electrophysiological component. The signal processor digitally low pass filters the combined signal and the output of the low pass filter is the electrophysiological signal. The signal processor then digitally bandpass filters the combined signal using a filter with a center frequency which is the same as the test frequency.

Abstract: A measuring system minimizes the parasitic affects of lumped circuit elements. The system includes two or more in-situ interfaces configured to conductively link a source to an internal load and an external load. The in-situ interfaces are linked to a shunt conductor. Two or more linear and dynamic elements conductively link the in-situ interfaces in series. The dynamic elements are configured to overwhelm the parasitic self-capacitance of an input circuit coupled to at least one of the in-situ interfaces. A shield enclosing at least one of the linear and dynamic elements has a conductive surface to fields and electromagnetic interference. The shield has attenuation ratios that substantially dampen the parasitic capacitance between the linear and dynamic elements that bridge some of the in-situ interfaces.

Abstract: A method is provided for measuring D-Q impedance of a component of a polyphase power grid connected to a grid node, and evaluating the margin of stability at a node using Nyquist diagrams generated from the measured D-Q impedance data. A generator, coupled to the polyphase power grid, is controlled to induce suppressed-carrier stimulus current into the grid node. Circuitry measures response signals of suppressed-carrier form existing within a bus voltage at the grid node and a branch current of the component being measured. The method includes measuring complex voltage components of the response signals contained in the bus voltage and complex current components of the response signals contained in the branch current to form simultaneous equations that are resolved to determine the D-Q impedance parameters Zqq, Zqd, Zdq and Zdd of the measured component.

Abstract: A method of controlling an analog signal in an integrated circuit includes generating a first control signal having a first predetermined duration within the integrated circuit. The first control signal is configured to cause the analog signal to have a first signal level. The first signal level is compared to a level of a target signal. A second control signal is generated within the integrated circuit based on a result of the comparison. The second control signal is configured to cause the analog signal to have a second signal level. The second control signal has a second predetermined duration that is different than the first predetermined duration.

Abstract: An apparatus for measuring response time of a display apparatus including a photographing part including a charge coupled device camera and a microscope, an image processing part receiving a picture taken from a photographing part and calculating the response time thereof, and a control part applying a predetermined image signal to the display apparatus and controlling the photographing part to take a picture change of the display apparatus at a predetermined time.

Abstract: A system and method of integrated circuit control for in situ impedance measurement including a system with a plurality of functional partitions in a clocked logic type integrated circuit, the functional partitions having a communication controller and a modulation gate, the modulation gate receiving a clock signal and a modulation signal and generating a modulated clock signal for the functional partition; at least one of the communication controllers receiving an in-band signal and selectively communicating the in-band signal to the other communication controllers; and at least one of the functional partitions having a modulator, the modulator receiving the clock signal and a modulation control signal and generating the modulation signal.

Abstract: A apparatus and method for creating a universally usable and configurable sensor platform which is used in conjunction with various sensor and sensing elements to sense and measure environmental conditions which incorporates inputs from multiple sensors 6-9 and 12-14. The apparatus incorporates an oscillator 3 which provides a signal whose frequency varies according to the inputs from sensors 6-9 and 12-14 in combination with a microprocessor 1. A cordic block 61 allows for supplemental calculations of trigonometric operations and functions. An output unit 2 converts the signals received from microprocessor 1 into a variety of serial protocols.

Abstract: A control arrangement and method is provided for detecting and responding to disturbances in electrical power systems. In a preferred arrangement, an integration is initiated that is based on a comparison of actual voltage of a source and a reference voltage. When the integration exceeds a predetermined value, the source is considered unreliable. Also in a preferred arrangement, a determination is made as to whether or not the disturbance is a downstream fault condition. For example, this is useful for applications where a transfer is made from a first source to a second source when predetermined disturbances are detected. In this manner, the transfer of the load to a second source is avoided which would continue the supply of the downstream fault. Additionally, the arrangement distinguishes between various degrees of disturbances to permit appropriate response based on the severity and type of disturbance. For example, a first immediate response, i.e.

Abstract: A test apparatus and method of measuring pulling of the frequency of an oscillator. The apparatus includes a bias tee, a power supply, a spectrum analyzer, a second power supply, a symmetrical resistive power splitter, a power meter and a synthesized signal generator. The method includes sweeping the synthesized signal generator frequency from the nominal frequency down to a first frequency. The first frequency is recorded when the oscillator goes out of frequency lock as a first pulling frequency. The synthesized signal generator frequency is then sweet from the nominal frequency up to a second frequency and the second pulling frequency is recorded when the oscillator goes out of frequency lock. The difference between the first and second pulling frequencies is the peak to peak pulling value.

Abstract: A method and apparatus for generating a transmembrane voltage, including a semiconductive substrate having a surface for receiving a membrane thereon, and a light source for illuminating at least a portion of the semiconductive substrate. Measurement of current through the membrane addresses ion channels through the membrane at the location illuminated by the light source.

Abstract: A main power source supplies current through path impedance to a power terminal of an integrated circuit device under test (DUT). The DUT's demand for current at the power input terminal temporarily increases following edges of a clock signal applied to the DUT during a test as transistors within the IC switch in response to the clock signal edges. To limit variation (noise) in voltage at the power input terminal, an auxiliary power supply supplies an additional current pulse to the power input terminal to meet the increased demand during each cycle of the clock signal. The magnitude of the current pulse is a function of a predicted increase in current demand during that clock cycle, and of the magnitude of an adaption signal controlled by a feedback circuit provided to limit variation in voltage developed at the DUT's power input terminal.

Abstract: An oscillating circuit is disclosed which is responsive to frequency variations caused by parameter changes in an associated slow wave structure sensitive element. A local oscillator and mixer circuit is used to subtract an offset frequency output to reset the oscillation frequency of the slow wave structure so that the output frequency will be in a range starting substantially at zero.

Abstract: A semiconductor memory device is provided, which includes a chip enable buffer and an address buffer. The chip enable buffer generates first and second control signals having opposite phases of logic, the first and second control signals enable and disable operations of the semiconductor memory device, respectively. The address buffer includes an input terminal, and a blocking terminal connected to the input terminal, the input terminal receiving an external address signal under control of the first control signal, and the blocking terminal generating an address signal in response to the second control signal. The address buffer further includes a shift detecting circuit connected to the blocking terminal for generating first and second short pulses by detecting shift of the address signal, wherein the pluses are used as signals for reading data of the semiconductor memory device.

Abstract: Apparatus for coupling an auxiliary ac power source to electrical circuits in parallel with a primary ac power source comprises a “meter extender” that is adapted for installation installed between a kilowatt-hour meter and socket for the meter. The meter extender comprises contact terminals on one side that mate with contact terminals forming part of the meter socket and additional contact terminals on a second side that mate with contact terminals forming part of the meter.

Abstract: A method and circuitry for implementing a built-in self test (BIST) for determining the frequency characteristics of filter circuits in mixed-signal integrated circuits (ICs). The method comprises inserting a Circuit Under Test (CUT) into a feedback loop that looks like a sigma delta modulation loop and adjust the feedback loop so that it oscillates at the cut-off frequency of the filter. The frequency of oscillation can then easily be measured using either on on-chip counter or digital automated testing equipment. The feedback loop preferably comprises a comparator, a phase-delay component, such as a delay-line, and a one-bit DAC (digital-to-analog converter), wherein the comparator is connected to the output of the CUT, and the output of the one-bit DAC is connected to the input of the CUT. The phase delay of the feedback loop can be tuned through adjustment of the delay-line (e.g., an n-length shift register) until an oscillation frequency is obtained.

Abstract: A monitoring system for the affirmative measurement of feed levels in a bin includes a vertically disposed series of pressure sensors carried on a flexible detector strap releasably mounted at the center of the feed bin. The sensors include radially projecting blades that deflect and actuate in response to the downward flow of material being discharged. The signals from the sensors are routed to a local monitoring site permitting on-site determination of fill level. The signals from plural bins may also be routed to a central monitoring site. The local monitoring site is preferably provided with a programmable logic controller for periodically recording the level of the feed bin. The fill data is remotely retrievable for use in determining resupply needs. The system may also beneficially incorporate a modem communications link with a remote service monitoring site.

Abstract: Disclosed is anew technique for measuring the resistivity of ultra-thin carbon films (less than 200 Å). The technique involves using a probe with very smooth surface, a thin layer lubricant (20-30Å)that enables the intimate and stable electrical contact between probe and the thin film, and measurement of I-V curve to determine resistance. Resistivity measurements were conducted on carbon films doped with hydrogen and nitrogen at different mixture ratios and different thicknesses, and the results were compared with those obtained on a commercially available machine that uses a mercury probe. The advantages of the present technique include simple in use, less expensive and quick measurements with reasonably good accuracy.

Abstract: A phase-locked loop (PLL) is provided, which includes a PLL reference input, a PLL output and a phase detection loop coupled between the PLL reference input and the PLL output. The phase detection loop has a loop filter node. A delay element is coupled within the phase detection loop and has a variable delay, which can be increased to a critical delay at which the phase detection loop becomes unstable. A demodulator is coupled to the loop filter node and is adapted to demodulate a modulated voltage on the loop filter node. The demodulator has a demodulated output, which is representative of a phase margin of the phase detection loop when the delay element has the critical delay.