Abstract: Certain aspects are directed to an intermodulation detection sub-system. The intermodulation detection sub-system includes a test signal generation module, at least one intermodulation detection device, and a controller. The test signal generation module is integrated into a unit of a telecommunications system. The test signal generation module is configured to provide a test signal to a remote antenna unit of the telecommunications system. The intermodulation detection device is integrated into the telecommunications system. The intermodulation detection device is configured to detect intermodulation products generated by mixing a first signal component and a second signal component of the test signal. The controller is integrated into the unit. The controller is configured to control the test signal generation module and the at least one intermodulation detection device.

Abstract: The present invention relates to a measurement apparatus, comprising a measurement unit configured to at least one of receive and transmit a measurement signal; a shield configured to electrically shield said measurement unit; at least one close range communication interface configured to transfer data to an external portable device; and at least one indicator which indicates a connection region for connecting said external portable device to said at least one close range communication interface.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to measure a resonant sensor based on detection of group delay. An example apparatus includes a modulation manager configured to query the resonant sensor with a modulated signal including a frequency; and a resonance determiner configured to determine a resonance frequency of the resonant sensor based on a group delay associated with the resonant sensor and the frequency.

Abstract: A predictive brownout prevention system may be configured to prevent brownout of an audio output signal. Particularly, the brownout prevention system may be configured to receive information indicative of an amplitude of the audio input signal, receive information indicative of a condition of the power supply, receive information indicative of one or more of the following: 1) adaptive estimates of power supply conditions; 2) anticipated effects of power supply capacitance; and 3) condition of a load impedance, determine from the received information whether a brownout condition exists, and responsive to determining the brownout condition exists, generate the selectable attenuation signal to reduce an amplitude of the audio output signal such that the signal path attenuates the audio input signal or a derivative thereof in order to prevent brownout prior to propagation to the audio output of a portion of the audio input signal having the brownout condition.

Abstract: A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.

Abstract: A system and method for detecting resonant frequency of a corona igniter concurrent with operation of the corona igniter is provided. The method includes providing a plurality of pulses of energy to the corona igniter, each having a pulse duration and spaced from one another by a deadtime duration during which no energy is provided to the corona igniter. Each pulse duration is ceased before current flowing in the corona igniter crosses zero, and each zero crossing of the current occurs during one of the deadtime durations. The next pulse of energy is provided to the corona igniter in response to the zero crossing of the current. A resonant frequency value is then obtained based on a sum of the pulse and deadtime durations of two consecutive cycles, or the time between zero crossings. The resonant frequency values become more accurate over time, and the drive frequency is adjusted accordingly.

Abstract: A micro-system, for example a micro-sensor, includes a resonator 10 with vibrating element(s) 11 receiving an excitation signal E of a loop 20 for automatic gain control, as a function of an amplitude setpoint (C) and providing as output a signal y(t) defined by a peak amplitude having a nominal value A0 dependent on the said setpoint and a resonant frequency. The micro-sensor integrates a circuit for measuring a quality factor of the resonator based on a measurement of an attenuation of the output signal during a momentary phase of cutoff of the excitation signal E applied to the resonator. This circuit for measuring the quality factor is configured so as to activate the excitation signal cutoff phase, for a duration of cutoff Td such that at the end of the cutoff phase, the peak amplitude of the output signal is attenuated by factor to the nominal peak amplitude A0 at the start of the cutoff phase, by a factor k with 1<k?2.

Abstract: A device, a system and a method for detecting an irregularity in a structure of an aircraft are proposed. The device includes a resonant circuit with a resonance frequency and a probe for tuning the resonance frequency of the resonant circuit. The resonant circuit and the probe are operatively connected in such a way that the probe changes the resonance frequency of the resonant circuit if the structure changes due to a formation of an irregularity.

Abstract: A position sensor arrangement has a transformer based position sensor and a cable peaking correction apparatus. The cable peaking correction apparatus is coupled to at least one of a transformer based position sensor excitation input and the plurality of outputs from the transformer based position sensor.

Abstract: An integrated circuit comprises at least first and second frequency generating circuits, wherein each frequency generating circuit comprises a reference frequency source; a voltage controlled oscillator; and a feedback control circuit for controlling the voltage controlled oscillator to provide a desired output frequency signal. The output of the voltage controlled oscillator of the first frequency generating circuit is switched into the feedback control circuit of the second frequency generating circuit to provide a test signal for testing one or more components of the feedback control circuit of the second frequency generating circuit.

Abstract: An apparatus (100) for feeding antenna elements of a phased array antenna, comprises: at least two transmission lines (101, 101) disposed in parallel and operated at a certain frequency as resonators, each of the transmission lines (101, 101) having a predetermined length dimensioned to be at least approximately an electrical quarter-wavelength of the operating frequency, a plurality of measuring positions provided on the transmission lines (101, 101) in spacings along the longitudinal direction (x) of the transmission lines, wherein each measuring position on one of the two transmission lines (101) faces directly a corresponding neighbored measuring position on the other transmission line (101) and such corresponding measuring positions being adjacent to each other in a direction transverse to the longitudinal direction of the transmission lines (101, 101) form a measuring position pair, respectively, wherein each of the circuits (110, 120, 130) detects and amplifies/attenuates the measuring signals from an

Abstract: The described embodiments provide a configurable pulse generator circuit. More specifically, the described embodiments include a pulse generator circuit; an inverting difference oscillator (IDO) enabling circuit coupled to the pulse generator circuit; and a disable signal coupled to the IDO enabling circuit. When the disable signal is asserted, the IDO enabling circuit is disabled and the pulse generator circuit is configured as a pulse generator. In contrast, when the disable signal is deasserted, the IDO enabling circuit is enabled and the pulse generator circuit is configured as part of an IDO.

Abstract: An apparatus for sensing analyte is provided. The apparatus may include a plurality of sensor array columns, each sensor array column including a plurality of sensors, each sensor being adapted for sensing one or more parameters in reaction to the presence of one or more analytes and output a current therefrom in accordance with level of the sensed parameter, a Voltage Controlled Oscillator (VCO) array including a plurality of VCOs, each VCO adapted to receive an output current from one of the plurality of sensors from each of the plurality of sensor arrays and for and generating an output oscillation frequency in accordance with the level of the received output current, and a counter array including a plurality of counters, each counter adapted to receive an output from a corresponding VCO and count a number of oscillations over a predetermined time.

Abstract: An apparatus for determining a resonant frequency of a wind turbine tower is provided. The apparatus includes a processing unit configured to receive an acceleration measurement value, the acceleration measurement value representative of the acceleration of the wind turbine tower in the direction parallel to a rotor rotational axis of the wind turbine and/or in the direction perpendicular to both the rotor rotational axis and the tower axis of the wind turbine. The apparatus includes a memory configured to store a series of acceleration measurement values, and the processing unit includes a Fourier transform module configured to calculate a spectral vector based on calculating a convolution-based fast Fourier transform of the series of acceleration measurement values, and includes a resonant frequency calculation module configured to calculate the tower resonant frequency based on the calculated spectral vector.

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: An apparatus (100) for feeding antenna elements of a phased array antenna, comprises: at least two transmission lines (101, 101) disposed in parallel and operated at a certain frequency as resonators, each of the transmission lines (101, 101) having a predetermined length dimensioned to be at least approximately an electrical quarter-wavelength of the operating frequency, a plurality of measuring positions provided on the transmission lines (101, 101) in spacings along the longitudinal direction (x) of the transmission lines, wherein each measuring position on one of the two transmission lines (101) faces directly a corresponding neighbored measuring position on the other transmission line (101) and such corresponding measuring positions being adjacent to each other in a direction transverse to the longitudinal direction of the transmission lines (101, 101) form a measuring position pair, respectively, wherein each of the circuits (110, 120, 130) detects and amplifies/attenuates the measuring signals from an

Abstract: A system for testing radio frequency (RF) communications of a device capable of such communications is provided. The system includes a chamber for isolating the device from RF interference, an antenna that is suitable for RF communications with the device wherein the antenna is capable of communications over a range of frequencies, the antenna being located within the chamber, and a digital communication link for providing non-RF communications with the device.

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: The present invention relates to an arrangement (1) for detection of a first resonance frequency (F1), related to a mass (1b?) loaded carrier means (1b), and to compare said first resonance frequency (F1) with a second, as a reference used, resonance frequency (F2), related to said carrier means (1b), by using frequency comparing and/or calculating means (3, 4) to evaluate, by a noted frequency shift (F2-F1), a mass weight (1b?). An array of individual carrier means (1a, 1b . . .

Abstract: The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.

Abstract: Aspects of the present invention determine the resonant frequency of a sensor by obtaining sensor signals in response to three energizing signals, measuring the phase of each sensor signal, and using a group phase delay to determine the resonant frequency. The phase difference between the first and second signal is determined as a first group phase delay. The phase difference between the second and third signal is determined as a second group phase delay. The first group phase delay and second group phase delay are compared. Based on the comparison, the system may lock on the resonant frequency of the sensor or adjust a subsequent set of three energizing signals.

Abstract: Methods for determining the resonant frequency for interrogation of a resonant device include steps for generating and transmitting RF interrogation pulses of various bandwidths to energize one or more SAW resonator elements. Initial RF interrogation pulses have a relatively wide bandwidth, such that the general location of a resonant device's resonant frequency can be expediently determined. Then, interrogation pulses having smaller bandwidth pulses can be transmitted near the determined general location of resonance to further narrow the location of resonance. In some emodiments, one or more initial interrogation pulses are transmitted in the center of or at an expected value within a range of operation of a resonant device.

Abstract: Power measuring receiver (PMR) methods and apparatus for measuring power of signals are provided in which a high frequency measuring circuit (HFMC), a conversion measuring circuit (CMC), and an intermediate frequency measuring circuit (IFMC) work in conjunction with each other to measure a wide power range of signals. The HFMC may measure relatively high power signals at high frequency. The CMC may convert the high frequency signal into an intermediate frequency signal so that both the CMC and the IFMC can accurately measure low power signals. The CMC may also set the minimum noise bandwidth associated with gain stages in the IFMC. The intermediate frequency may provide the IFMC with the ability to perform low power measurements at a reduced DC power consumption.

Abstract: A method and self-tuning circuit for tuning vibratory transducers, broadly including electroacoustic speakers and specifically including the speakers of common back-up alarms used for safety reasons on commercial vehicles and heavy equipment. The self-tuning circuit is physically coupled to the transducer's input terminals and operates by comparing the rising and falling edges of one period of a test waveform elicited from the transducer by the application of a test signal having a test frequency. Depending on the results of this comparison, the test frequency is adjusted by predetermined increments upward or downward until the transducer's resonance frequency has been tightly bracketed though not exactly pinpointed.

Abstract: An intermodulation detector (11) that operates standalone or in parallel with a radio receiver (10) of a radio receiver system (100) including a receiver tuning logic module (12), and, in the case of operating standalone, provides signals conveying information about intermodulation power in the receiver frequency band, and in case of operating in parallel with a radio receiver (10), provides to the receiver tuning logic module signals conveying information about power aliasing into the frequency band to which the radio receiver is tuned.

Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method comprises the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.

Abstract: Power measuring receiver (PMR) methods and apparatus for measuring power of signals are provided in which a high frequency measuring circuit (HFMC), a conversion measuring circuit (CMC), and an intermediate frequency measuring circuit (IFMC) work in conjunction with each other to measure a wide power range of signals. The HFMC may measure relatively high power signals at high frequency. The CMC may convert the high frequency signal into an intermediate frequency signal so that both the CMC and the IFMC can accurately measure low power signals. The CMC may also set the minimum noise bandwidth associated with gain stages in the IFMC. The intermediate frequency may provide the IFMC with the ability to perform low power measurements at a reduced DC power consumption.

Abstract: A low voltage, low current apparatus for detecting discontinuities, such as bubbles, in a fluid stream, in which a tube is placed between a transducer transmitting successive bursts of ultrasonic energy and for receiving the bursts. The receiving transducer is connected to a low current transistor amplifier circuit of a signal processing circuit which keeps an output in a first state when signals are received corresponding to the presence of a fluid and in a second state when the bursts of energy are modified by the discontinuity.

Abstract: A measuring method and a sensor device measure chemicals in pharmaceutical analysis and synthesis. According to the method, the course of a reaction is detected by a change of frequency of a high frequency oscillator. The sensor device includes a measuring cell in which the reaction takes place, said measuring cell forming part of a resonator of an HF-oscillator.

Abstract: A load pull circuit with a monitoring port which provides a constant VSWR throughout a phase variation in excess of 360°. The fundamental circuit comprises a fixed resistor of fifty ohms placed in series with an external fifty ohm load monitoring port resistor to ground. In parallel with the two series resistors, which total 100 ohms, is placed a 33.3 ohm resistor that is connected to ground through a series L-C circuit. The capacitance in the L-C circuit is adjustable and can be varied to cause the L-C circuit to change in net value from being inductive, to being resonant, and finally being capacitive. This causes the 33.3 ohm resistor to be connected to ground through an inductor, then through a short, and finally through a capacitor, making the load pull circuit present a load that vary through 360 degree in phase, while still remaining at a VSWR of 2:1. The inductor in the L-C circuit is a varactor, making the sweep through all 360° totally electronically controllable and simple to automate.

Abstract: Methods are provided for determining deviations from &phgr;=0° in test resonators based on the quasi-pure modes' displacement ratio variations with 4 angle. A direct relationship between deviation from &phgr;=0° and the c-mode displacement ratio has been observed, so that the larger the deviation from &phgr;=0°, then the larger is the change in the normalized frequency of the c-mode upon immersion in, or contact with, a fluid. The method comprises measuring &thgr; and &phgr; angles in reference resonators with different small &phgr; angles and quasi-pure mode frequencies of reference resonators in both air and a test fluid at ambient temperatures, calculating the normalized frequency changes between the air and fluid measurements as a reference point, measuring the test resonator in air then in the fluid and comparing the results.

Abstract: A method and self-tuning circuit for tuning vibratory transducers, broadly including electroacoustic speakers and specifically including the speakers of common back-up alarms used for safety reasons on commercial vehicles and heavy equipment. The self-tuning circuit is physically coupled to the transducer's input terminals and operates by comparing the rising and falling edges of one period of a test waveform elicited from the transducer by the application of a test signal having a test frequency. Depending on the results of this comparison, the test frequency is adjusted by predetermined increments upward or downward until the transducer's resonance frequency has been tightly bracketed though not exactly pinpointed.

Abstract: An electrical circuit having an oscillator and additional structural elements that are connected to the oscillator. In an iterative method, upon variation of circuit parameters of the additional structural elements, the following steps are carried out for each instance of the circuit parameters: a stability analysis of the circuit is carried out for each respective instance, and if the circuit oscillates, a first value is assigned to the instance in a matrix in which all the instances being examined are stored. Otherwise, a second value is assigned to the instance in the matrix.

Abstract: A method and apparatus for measuring the frequency of a desired resonant mode of a crystal arrangement, or other two-port device, during an automated operation. The crystal arrangement, or other two-port device, is placed into a test circuit and subjected to a sinusoidal test signal of known frequency. Based upon the output response of the crystal arrangement to the test signal, the frequency of the test signal is changed such that the test signal rapidly converges on a desired mode of operation of the crystal arrangement. This is accomplished by first noting a desired increase in amplitude of the output response of the crystal arrangement, followed by measuring an error signal related to the desired crystal arrangement mode of operation. When the error equals a predetermined value the frequency of the sinusoidal test signal is the frequency of the desired mode.