Abstract: A change in impedance of a electromechanical resonating sensor is utilized to detect and/or measure a change in mass accumulated on the sensor. The impedance is monitored at a fixed frequency. The fixed frequency may be at or near the resonance frequency of the sensor. In various configurations, the sensor comprises a quartz crystal microbalance sensor or a piezoelectric cantilever sensor.

Abstract: A proximity sensor has an oscillation circuit, an amplitude measurement circuit, a control circuit and a signal processing circuit. The oscillation circuit has an LC resonant circuit and an oscillation control circuit that is configured to supply an electric current to the LC resonant circuit to generate oscillating voltage across the LC resonant circuit. The amplitude measurement circuit is configured to produce an amplitude signal corresponding to the amplitude of the oscillating voltage. The control circuit is configured to set the negative conductance of the oscillation control circuit to a critical value by which the LC resonant circuit can oscillate based on the amplitude signal. The signal processing circuit is configured to produce a distance signal corresponding to the distance between an object and the sensing coil based on a parameter associated with the negative conductance.

Abstract: Systems and methods for identifying problems with PZT elements of micro-actuators are provided. In certain example embodiments, a voltage (e.g., a sine voltage) may be applied to a reference unit causing it as well as a test unit to vibrate. Characteristics of the respective resonances (e.g., frequency, amplitude, phase, etc.) may be compared (e.g., by a processor) to determine whether there are problems with the test unit. The reference unit may include an HGA or an HSA of a hard disk drive device. The test unit may include corresponding parts for inspection. Such techniques make it possible to detect problems with PZT elements when there is only one PZT element per micro-actuator.

Abstract: A capacitive ultrasonic transducer includes a flexible layer, a first conductive layer on the flexible layer, a support frame on the first conductive layer, the support frame including a flexible material, a membrane over the support frame being spaced apart from the first conductive layer by the support frame, the membrane including the flexible material, a cavity defined by the first conductive layer, the support frame and the membrane, and a second conductive layer on the membrane.

Abstract: A technique is disclosed for determining capacitive, inductive, and resistive components of power line impedance via a portable line impedance measurement system. The measurement system includes a circuit that switches a burden resistor between power line conductors to cause a droop in a voltage waveform. The voltage waveform is sampled prior to inclusion of the resistor in the circuit, as well as after to identify the droop. The short circuit between the power lines is then removed by opening the circuit and a first effective capacitance in the test circuitry causes a resonant ring due to the inductive component of the power line impedance. The process is repeated a second time with a second effective load capacitance enabled in the test circuitry to cause a second resonant ring. Based upon the frequency of the rings and the voltage measurements, the individual impedance components of power line impedance can be computed.

Abstract: Wireless sensors configured to record and transmit data as well as sense and, optionally, actuate to monitor physical properties of an environment and, optionally, effect changes within that environment. In one aspect, the wireless sensor can have a power harvesting unit; a voltage regulation unit, a transducing oscillator unit, and a transmitting coil. The voltage regulation unit is electrically coupled to the power harvesting unit and is configured to actuate at a minimum voltage level. The transducing oscillator unit is electrically coupled to the voltage regulation unit and is configured to convert a sensed physical property into an electrical signal. Also, the transmitting coil is configured to receive the electrical signal and to transmit the electrical signal to an external antenna.

Abstract: Methods and computer storage media provide for the installation of potted inserts and installation validation. According to embodiments described herein, an insert is placed within an insert aperture of a panel or other structure. Potting compound is injected into a potting cavity surrounding the insert through a fill hole in the insert until potting compound overflows from another fill hole. The installation is validated by applying a force to the installed insert at a determined frequency using a mechanical impedance instrument and measuring a response frequency. The response frequency is compared to an acceptable frequency range to determine whether the insert is properly installed.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Abstract: A technique is disclosed for determining capacitive, inductive, and resistive components of power line impedance. A measurement circuit switches a burden resistor between power line conductors to cause a droop in a voltage waveform. The voltage waveform is sampled prior to inclusion of the resistor in the circuit, as well as after to identify the droop. The short circuit between the power lines is then removed by opening the circuit and a first effective capacitance in the test circuitry causes a resonant ring due to the inductive component of the power line impedance. The process is repeated a second time with a second effective load capacitance enabled in the test circuitry to cause a second resonant ring. Based upon the frequency of the rings and the voltage measurements, the capacitive, inductive, and resistive components of power line impedance can be computed.

Abstract: A microprocessor-controlled high voltage sensor circuit controls resonant operation of an induction coil—capacitor circuit. The sensor circuit includes an input that receives a high voltage signal from the induction coil—capacitor circuit, an attenuator coupled to the input, wherein the attenuator reduces the high voltage signal to a low voltage signal, a peak detector coupled to the attenuator, the peak detector that holds the low voltage signal and detects a peak value of the low voltage signal, a clipper circuit that limits an output voltage from the peak detector so as to prevent damage to components of the high voltage sensor circuit, and a linear amplifier that receives the low voltage signal from the clipper circuit and amplifies the low voltage signal for detection of resonance conditions in the induction coil—capacitor circuit by a microprocessor coupled to the high voltage sensor circuit.

Abstract: A method of selecting component values for an analog circuit includes identifying a cost function that evaluates similarity between an approximate frequency response function and a preferred frequency response function for at least one characteristic of the functions, determining the approximate frequency response function of the analog circuit based on an approximate component value, and changing the approximate component value based on a determined magnitude of similarity between the preferred frequency response function and the approximate frequency response function for the at least one characteristic. An impedance matching apparatus includes a mismatch detection circuit that produces a difference between source and load impedances, a match network controller that produces a control value based on the difference, and a reconfigurable varactor match network including at least one stub mounted varactor having a capacitance controlled by the control value to match the source and load impedances.

Abstract: Provided is a material for tactile sensor, which is easy to be formed, and in which the shape, size and orientation of coils dispersed in the medium are sufficiently controlled. The tactile-sensitive material comprises a medium and a plurality of micro coils dispersed in the medium and constituting a LCR resonance circuit, and wherein each of the plurality of micro coils comprises at least one spiral coil portion, and coil axes of the plurality of micro coils are aligned along at least one direction and/or directed in at least one plane. When a tactile stress is applied to the tactile-sensitive material, the C component is varied significantly, which contributes to the improvement in sensitivity of the tactile sensor. Further, by providing a core at the coil center, the sensitivity is more improved.

Abstract: A method for measuring intrinsic capacitance of a MOS device is provided. The MOS device includes a first terminal, a second terminal, a third terminal and a fourth terminal. First, provide a first input signal to the second terminal and ground the third terminal and fourth terminal. Then, charge the first terminal and measure a first current required for charging the first terminal. Afterward, provide a second input signal to the second terminal, ground the third terminal and the fourth terminal, and measure a second current required for charging the first terminal, wherein the first input signal and the second input signal have the same low level, but different high levels. Finally, determine intrinsic capacitance between the first terminal and the second terminal according to the first current, the second current and a high level difference between the first input signal and the second input signal.

Abstract: A technique is disclosed for determining capacitive, inductive, and resistive components of power line impedance via a portable line impedance measurement system. The measurement system includes a circuit that switches a burden resistor between power line conductors to cause a droop in a voltage waveform. The voltage waveform is sampled prior to inclusion of the resistor in the circuit, as well as after to identify the droop. The short circuit between the power lines is then removed by opening the circuit and a first effective capacitance in the test circuitry causes a resonant ring due to the inductive component of the power line impedance. The process is repeated a second time with a second effective load capacitance enabled in the test circuitry to cause a second resonant ring. Based upon the frequency of the rings and the voltage measurements, the individual impedance components of power line impedance can be computed.

Abstract: The invention relates to a device for analyzing the composition of the contents of a container, comprising: electromagnetic field emitting/receiving means (40) at least several frequencies comprised in a determined range of frequencies, means (22) supporting a container (R), the contents of which have to be analyzed, suitable for ensuring accurate relative positioning between the emitting/receiving means (40) and the container (R), means (50) capable of measuring the complex impedance of the emitting/receiving means influenced by the load formed by the container (R) and its contents, representative of the complex dielectric characteristics of the container and of its contents, means (53, 55) for obtaining at least one additional physical datum relating to a characteristic of the container (R), and means (50) capable of providing information relating to the nature of the contents of said container (R) depending on the measured complex impedance and on the additional physical datum

Abstract: An automotive urea solution monitoring device is deployed in conjunction with the urea tank of a selective catalytic reduction vehicle. An RF signal of a constant frequency may be generated across a resonant circuit, which may be comprised of an inductor and a PCB trace capacitor, or the like. Electromagnetic radiation is propagated into the automotive urea solution in the urea tank. The conductivity and dielectric properties of the liquid change the impedance of the discrete/trace capacitor and or the discrete/trace inductor. These changes are proportional to ammonia content, temperature, and/or level of the automotive urea solution in the urea tank and are preferably detected by a microcontroller, or the like, and then transmitted to a selective catalytic reduction vehicle engine management system, or the like.

Abstract: A capacitance probe for thin dielectric film characterization provides a highly sensitive capacitance measurement method and reduces the contact area needed to obtain such a measurement. Preferably, the capacitance probe is connected to a measurement system by a transmission line and comprises a center conductive tip and RLC components between the center conductor and the ground of the transmission line. When the probe tip is in contact with a sample, an MIS or MIM structure is formed, with the RLC components and the capacitance of the MIS or MIM structure forming a resonant circuit. By sending a driving signal to the probe and measuring the reflected signal from the probe through the transmission line, the resonant characteristic of the resonant circuit can be obtained. The capacitance of the MIS or MIM structure is obtainable from the resonant characteristics and the dielectric film thickness or other dielectric properties are also extractable.

Abstract: An arrangement and method are provided for determining the distance between an objective of a microscope and a sample examined with the microscope. Fitted on the objective or in the immediate vicinity of the objective is a capacitive sensor in whose measuring range the sample and/or a microscope slide supporting the sample is located or into which it can be brought. The sample and/or the slide causing a measurable change in the capacitance of the sensor. From the change in the capacitance of the sensor, the distance of the sample and/or of the microscope slide from the sensor is determined, and thus the distance of the sample from the objective. A capacitive distance sensor can be applied in such an arrangement by which a stray field can be generated between at least two electrodes. The capacitance experiences a measurable change owing to an object introduced into the stray field. The electrodes of the sensor are arranged as substantially coaxial lateral surfaces.

Abstract: A remote sensing device includes a sensor and reference circuit. A resonant circuit of the sensor has a resonant characteristic modifiable by exposure to an external condition. The sensor is configured to produce a sensor signal associated with the modifiable resonant characteristic. A reference circuit of the remote sensing device is configured to produce a reference signal suitable for use in conjunction with the sensor signal. The reference signal is used to account for variations of the sensor signal due to variations in the inductive coupling between the remote sensing device and a reader designed to detect the reference signal and the sensor signal.

Abstract: An apparatus for diagnosing motor damping network integrity, the motor damping network configured for selective short-circuiting of the windings of a motor in a motor control system. The apparatus includes a motor controller with a motor drive portion thereof electrically isolated from the windings of the motor. A resonant network is based on the windings of the motor, the damping network, and a remaining non-isolated portion of the controller. An amplifier circuit applies an excitation signal to the resonant network. A detector circuit detects a response of the resonant network based on the excitation signal. A state of the damping network is determined based on the response.

Abstract: A method of making a resonant frequency tag which resonates at a predetermined frequency. The method involves providing a first conductive pattern having an inductive element and a first land and a second conductive pattern having a second land and a third land which are joined together by a link. The second conductive pattern is overlaid the first conductive pattern such that the second land is positioned over the first land. The third land is in electrical communication with the inductive element of the first conductive pattern. The formed resonant frequency tag is energized to determine if the tag resonates at the predetermined frequency. If the tag resonates properly, the third land is electrically coupled to the inductive element. If it does not, the second conductive pattern is adjusted so that overlapping portions of the first and second lands are changed, altering the capacitance to adjust the resonant tag frequency.

Abstract: The present invention provides a capacitive sensing apparatus having utility in object detection security applications whereby the object detection field generated by the apparatus is made steerable. The apparatus includes a power source having a ground connection in communication with at least one sensing circuit operative to detect an object moving within the sensing field. At least one conductive element is provided in communication with electrical ground. To steer the direction of the sensing field, the relative position and distance between the conductive element and the sensing circuit is adjusted such that a desired sensing field pattern is obtained.

Abstract: A technique for determining inductive and resistive components of power line impedance. A measurement circuit switches a burden or drain resistor between power line conductors to cause a droop or sag in a voltage waveform. The voltage waveform is sampled prior to inclusion of the resistor in the circuit, as well as after to identify the droop. The short circuit between the power lines is then removed by opening the circuit and a capacitor in the test circuitry causes a resonant ring due to the inductive component of the power line impedance. Based upon the period or frequency of the resonant ring, and upon the voltage measurements with and without the resistor in the circuit, the inductive and resistive components of power line impedance can be computed.

Abstract: A method of making a resonant frequency tag having a predetermined frequency comprises forming a first conductive pattern comprising an inductive element and a first land having a first end connected to an inductive element end, and a second end spaced a predetermined distance from the first end; separately forming a second conductive pattern comprising a second land having a predetermined width and a link element; placing the second conductive pattern proximate the first conductive pattern at a first location wherein the second land overlies a portion of the first land with a dielectric therebetween establishing capacitive element plates having a first capacitance along with the inductive element forming a resonant circuit; measuring the resonant circuit frequency and comparing the measured and predetermined frequencies moving the second land along of the first land length to match the resonant frequency; and securing the second conductive pattern to the first conductive pattern.

Abstract: There is provided a secondary reactive termination circuit connected between the output of the RF power generator and the input of the plasma chamber to allow the tight regulation or limiting of the voltage and current components of the secondary frequencies within the process plasma. The secondary reactive circuit controls the impedance of the match network designed primarily to operate at the fundamental frequency of the RF power generator as seen by secondary frequencies in the system. Power delivery components are measured at the connection point of the termination circuit and used as feedback signals to control variable values of the termination circuit components.

Abstract: Inner individual electrodes are formed at intervals on a piezoelectric ceramic layer so as to correspond in a one-to-one relationship with ink channels, and an inner common electrode are formed on another piezoelectric ceramic layer. The required number of piezoelectric ceramic layers with inner individual electrodes and with an inner common electrode are laminated alternately. An outer common electrode is connected to the inner common electrodes, and outer individual electrodes are connected to the respective inner individual electrodes. The capacitance between the outer common electrode and each of the outer individual electrodes is measured. A polarization electric field adjusted based on the measured value is applied between the common electrode and each of the outer individual electrodes to perform polarization.

Abstract: A radio frequency security element is provided for electronic surveillance of articles of merchandise. The security element comprises a lower strip conductor (1) and an upper strip conductor (5), which are wound in opposite directions. The upper and lower strip conductors and superimposed and connected in a common contact zone. The coil turns of the two conductor strips each have an included angle of rotation less than 2?. The security element has an improved detection rate and is particularly stable against changes in the resonance frequency.

Abstract: A testing device is operative to sense or monitor a radiated field emitted by an igniter for heating equipment such as an oil burner and to indicate the detection corresponding to a normal operating state of the igniter.

Abstract: A method of making a resonant frequency tag which resonates at a predetermined frequency. The method involves providing a first conductive pattern having an inductive element and a first land and a second conductive pattern having a second land and a third land which are joined together by a link. The second conductive pattern is overlaid the first conductive pattern such that the second land is positioned over the first land. The third land is in electrical communication with the inductive element of the first conductive pattern. The formed resonant frequency tag is energized to determine if the tag resonates at the predetermined frequency. If the tag resonates properly, the third land is electrically coupled to the inductive element. If it does not, the second conductive pattern is adjusted so that overlapping portions of the first and second lands are changed, altering the capacitance to adjust the resonant tag frequency.

Abstract: There is provided a secondary reactive termination circuit connected between the output of the RF power generator and the input of the plasma chamber to allow the tight regulation or limiting of the voltage and current components of the secondary frequencies within the process plasma. The secondary reactive circuit controls the impedance of the match network designed primarily to operate at the fundamental frequency of the RF power generator as seen by secondary frequencies in the system. A variable capacitor gives the operator the advantage of being able to tightly regulate the voltage, current, and power within a process at discrete frequencies without concern for impedance variability induced by other components in the system.

Abstract: The system comprises at least one electronic sensor for detecting the presence of moisture. The system further comprises at least one reading device for obtaining information from the sensor about the presence of moisture. The sensor comprises a resonant circuit which is at least partly formed from a moisture sensitive material, the electrical resistance of which increases when the material comes into contact with moisture. The reading device comprises transmitter-receiver means for generating an elecromagnetic interrogation field.

Abstract: The effects of electromigration have been shown to lead to damage of metal electrodes of electronic devices such as thin film resonator (TFR) devices in only a few hours, for a test input power that is within the operational range of these devices. It has been determined that this failure is sensitive to the frequency of the input power. The present invention provides a method and apparatus for determining high power reliability in electronic devices, so as to enable an accurate determination of the failure time of the electronic device, and hence projected lifetime. This determination is independent from the frequency of an input power applied to the electronic device as part of the method for testing the device. Based on the above results, a TFR device has been developed, which includes a protective or electromigration-reducing layer such as titanium being deposited atop an electrode of the device.

Abstract: A torsion oscillator (FIG. 1) is stabilized in operation by determining the current resonant frequency (62); in a first procedure, observing the oscillator for change in resonant frequency (64), and then restoring the amplitude and median offset (66) without changing the drive frequency. In an alternative procedure, after determining the resonant frequency (62); setting the drive frequency close to but offset from the current resonant frequency (74), observing the oscillator for change in resonant frequency (76), and the restoring the close offset to the changed resonant frequency (78). By operating slightly off peak, the direction of resonant change is immediately known. The first procedure has less difficulties in implementation, but requires more power.

Abstract: A distance measurement system is provided. The distance measurement system includes at least one resonant circuit, at least one magnetic element with predetermined magnetic properties, a transmitter operable to transmit an electromagnetic pulse, a receiver operable to detect oscillations emitted by said resonant circuit in response to said electromagnetic pulse, and an analyzer operable to analyze an amplitude envelope property of said oscillations, to thereby determine a distance between the resonant circuit and the magnetic element.

Abstract: A system and method for determining characteristics of a proximity sensor. According to a preferred embodiment, the admittance of a proximity sensor/cable assembly is measured at two frequencies. Assumptions about sensor characteristics and cable characteristics are made, and an admittance corresponding to the assumed characteristics is derived. The assumptions are adjusted to obtain a correspondence between the measured admittance and the derived admittance. When the assumptions have been updated a specified number of times or when a desired accuracy threshold has been met, the adjusted assumptions may be used to determine one or more sensor characteristics, such as the separation between the proximity sensor and the target object.

Abstract: The present invention provides a foil wound low profile power L-C processor. A magnetic winding is disposed within a core. The magnetic winding can be made of one or more sets of conductive foil and insulation film wound together in a spiral pattern. The magnetic winding can also include dielectric film. The magnetic winding can have a center aperture in which a non-magnetic and non-conductive center post can be disposed. The center post can also be divided into portions with a combined length less than the length of the center aperture to form an air gap within the center aperture.

Abstract: A temperature compensated pressure sensor network for providing an output sensing signal representative of an applied pressure includes a reference oscillator circuit for providing a reference signal having an associated reference frequency. The oscillator circuit includes a first inductor pair electrically coupled in series, wherein the reference frequency is a predetermined function of a first inductance associated with the first inductor pair. The sensor network further includes a sensor circuit for providing a sensing signal having an associated sensing frequency. The sensor circuit includes a second inductor pair and a sensing capacitor electrically coupled in series, wherein the sensing frequency is a predetermined function of a second inductance associated with the second inductor pair and the applied pressure. The sensor network also includes a processor for receiving the reference signal and the sensing signal, and producing the output sensing signal.

Abstract: A resonant converter and a control method for a resonant converter are proposed. The resonant converter comprises a resonant circuit with a transformer, which circuit is supplied with power by an AC inverter with a switched AC voltage, preferably a pulse-width modulated voltage. The circuit comprises a plurality of secondary units each consisting of a secondary winding of the transformer and at least one rectifier element (diode). The secondary units are subdivided into secondary units of the first and second type, secondary units of the first type and secondary units of the second type having opposite orientations. Secondary units of opposite types preferably have either with the same wiring a different winding orientation or with opposite wiring the same winding orientation.

Abstract: Disclosed is a position detection system for determining a state of a physical object. The position detection system includes a platform and a physical object positioned adjacent to the platform. The physical object has an object state that is changeable. The position detection system also includes a first resonator having a first resonator position state. The first resonator is arranged such that a change in the object state causes a change in the first resonator position state and such that the first resonator position state is different from the object state. The first resonator is further arranged to output a resonator signal that is associated with the first resonator position state when an excitation signal with a predetermined frequency range is received by the first resonator.

Abstract: Methods techniques have been developed for making dielectric measurements of materials in the near field of microwave antennas. These techniques overcome the limitations of previous devices as the size, shape, orientation, and location of a sample can have a substantial impact on dielectric measurements.

Abstract: A circuit for detecting the ignition of a fluorescent lamp at any dim position by comparing the phase of the current flowing through the lamp resonant output stage to a predetermined reference phase value. When the phase of the current is coincident with the predetermined reference phase, lamp ignition has occurred and the circuit automatically “closes the loop” so that the lamp power can be regulated (via phase control) to a user designated setting. The phase of the lamp resonant circuit current is measured in the present invention by detecting the zero-crossing of the inductor current as measured across a resistor disposed in the lamp resonant circuit. The only way for the phase of the inductor current to reach the reference phase is if the lamp ignites (provided the frequency is above the resonance frequency and is ramping smoothly from a high frequency down to the ignition frequency). The circuit is designed to wait approximately 10 cycles to avoid closing the loop before the lamp has struck.

Abstract: A method for testing whether an antenna circuit of a contactless chip card is defective. The antenna circuit is an inductive resonant circuit comprising a capacitor and an antenna coil. The antenna coil of the resonant circuit is excited by inductive coupling using a test coil wherein the excitation is then sharply interrupted. By detecting in the test coil a response signal generated by self-induction in the antenna coil of the resonant circuit and retransmitted to the test coil by inductive coupling, the response signal can be analyzed for determining whether a contactless chip card is defective. Application is well suited to the testing of antenna circuits for electronic portable devices working without contact, such as contactless chip cards, electronic labels, etc.

Abstract: In a method for seeking and setting a resonant frequency for a load impedance and a tuner for carrying out the method, a first frequency sweep is performed over a predetermined frequency interval in order to identify the resonant frequency within the predetermined frequency interval. To maintain the correct resonant frequency, regardless of signal drift and other interference, repeated sweeps are automatically performed within the predetermined frequency interval to identify the resonant frequency repeatedly. Alternating semi-sweeps can be performed to reduce the sweep duration.

Abstract: A method for testing an integrated circuit comprising an input capacitance designed to form, with an antenna coil, a resonant receiver circuit with a predetermined natural frequency. The input capacitance is connected to a test inductance chosen to form, with the input capacitance, a resonant test circuit having a resonant frequency substantially equal to the natural frequency of the resonant receiver circuit. The resonant test circuit is excited by an alternating signal provided through a transformer. The testing of inductive integrated circuits working without contact is implemented in a corresponding test system.

Abstract: A system for testing interconnects in multi-chip modules including a radio frequency resonator having a resonant circuit with a relatively high quality factor, the output of the resonant circuit being attached to a probe. Electrically coupled to the resonant circuit output is an apparatus to analyze the voltage signal output. The probe is applied to one end of an interconnect. When the probe is applied, the resonant frequency of the resonant circuit and the magnitude of the frequency response are altered due to the additional loading created by the interconnect. Due to the relatively high quality factor of the resonant circuit, the magnitude of the frequency response of the altered resonant circuit is measurably distinct from a predetermined reference magnitude at a predetermined reference frequency, thus indicating the existence of a defect.

Abstract: A planar electromagnetic resonator utilizes an electromagnetically active material located between the capacitive or inductive elements of the resonator. A microscopic electrical property of this material is altered by an external condition, and that alteration, in turn, affects the behavior of the resonator in a consistent and predictable manner.

Abstract: A stochastic resonator signal detector comprises a multi-stable nonlinear device for coupling to an input signal and a control signal coupled to the multi-stable nonlinear device for varying asymmetry among stable states of the multi-stable nonlinear device. The interaction of the input signal with the control signal in the multi-stable nonlinear device generates an output signal having an amplitude responsive to the input signal amplitude and a frequency range that comprises harmonics of products of the control signal and the input signal.

Abstract: A measuring system measures forces, deformations, and movements. The measuring system comprises at least one LC-circuit, at least one power supply for generating a voltage and a current in the LC-circuits, whereby the frequency, the amplitude, and the phase difference between the current and the voltage in a default situation are known and are furthermore a function of the variable to be measured, as well as at least one detection unit for detecting the frequency and/or the phase difference and/or the amplitude in the LC-circuit. The invention provides therewith a compact, simple and multifunctional measuring system by means of which a reading of the measured value is possible without contact with the subject.

Abstract: A convenient, non-optical method for scanning probe microscopy tip-to-sample distance control based on the impedance change in a shear-force dither piezo. This is accomplished by determining the tip-sample distance by measuring the impedance change in a shear-force piezo-member. A Wheatstone type bridge can be utilized to regulate the tip-sample separation. Alternatively, an electrical bridge, having an output, regulates the tip-sample separation relative to the bridge output by driving the piezo/tip with a sine wave and combining said sine wave with a phase-referenced wave of equal amplitude at a 180.degree. phase shift. The electronic bridge detects impedance changes of about -100 dB across loads with impedance phases between -90.degree. to +90. Power dissipation is determined by measuring changes in electric impedance that a dither piezo presents to an oscillator.

Abstract: A method of determining a response characteristic of a microwave device includes coupling a microwave resonator to the device, loading the resonator with microwave radiation, monitoring the time decay of power from the resonator, and comparing the monitored time decay with a known characteristic of the time decay of radiation in the microwave resonator when loaded with radiation.