A time-varying formant is generated at a formant frequency by generating first and second harmonic phase signals having first and second harmonic numbers, respectively, in relation to a modulation frequency. The first and second harmonic phase signals are generated in proportion to a master phase signal, which varies at the modulation frequency, modulo a factor corresponding to their harmonic numbers. First and second sound signals, based on the first and second harmonic phase signals, are frequency modulated to create an arbitrarily rich harmonic spectrum, depending on an FM index. The time-varying formant is generated by generating a time-varying combination of the first and second harmonic sound signals, weighting the first and second harmonic sound signals in accordance with their spectral proximities to the formant frequency. One or more of the harmonic numbers are updated when the time-varying formant frequency passes the frequency of either sound signal.

A method for generating/transmitting a transmission-unit symbol sequence is disclosed. In the case of transmission information, the information is modulated in time and frequency domains on the basis of a predetermined transmission unit (e.g., a transmission time interval TTI or slot), simultaneous transmission of the information is made, and then a transmission unit symbol is generated/transmitted. A transmission sequence is masked in each symbol contained in one transmission unit. Symbol-unit circular shift (cyclic shift) is applied to the masked result, so that transmission efficiency increases. A control signal transmission method for supporting a variety of formats and a signal transmission method based on a prime-length sequence are also provided.

A frequency modulating path for generating a frequency modulated clock includes a direct feed input arranged for directly modulating frequency of an oscillator, and a compensating feed input arranged for compensating effects of frequency modulating on a phase error; wherein the compensating feed input is resampled by a down-divided clock that is an integer edge division of the oscillator. A reference phase generator for generating a reference phase output includes a resampling circuit, an accumulator and a sampler. The resampling circuit is for resampling a modulating frequency command word (FCW) input to produce a plurality of samples. The accumulator is for accumulating the samples to generate an accumulated result. The sampler is for sampling the accumulated result according to a frequency reference clock, and accordingly generating a sampled result, wherein the reference phase output is updated according to at least the sampled result.

A frequency modulator includes a digitally-controlled oscillator (DCO) arranged for producing a frequency deviation in response to a modulation tuning word and a phase-locked loop (PLL) tuning word. In addition, another frequency modulator includes a DCO and a DCO interface circuit. The DCO is arranged for producing a frequency deviation in response to an integer tuning word and a fractional tuning word. The DCO interface circuit is arranged for generating the integer tuning word and the fractional tuning word to the DCO, wherein the fractional tuning word is obtained through asynchronous sampling of a fixed-point tuning word.

Embodiments of digital high-speed bi-phase modulator and method for bi-phase modulation are generally described herein. In some embodiments, the digital high-speed bi-phase modulator comprises a high-speed digital divider, a high-speed digital multiplexer, and matched signal paths provided between the divider and the multiplexer. The high-speed digital divider is configured to receive a carrier signal and generate complementary output signals. The high-speed digital multiplexer is configured to switch between the complementary output signals and generate a bi-phase modulated output at a carrier frequency (fc) modulated with a bi-phase code. The bi-phase code may be provided to control inputs of the multiplexer.

A radio frequency generator includes a power control module, a frequency control module and a pulse generating module. The power control module is configured to generate a power signal indicating power levels for target states of a power amplifier. The frequency control module is configured to generate a frequency signal indicating frequencies for the target states of the power amplifier. The pulse generating module is configured to (i) supply an output signal to the power amplifier, (ii) recall at least one of a latest power level or a latest frequency for one of the target states of the power amplifier, and (iii) adjust a current power level and a current frequency of the output signal from a first state to a second state based on the power signal, the frequency signal, and at least one of the latest power level and the latest frequency of the power amplifier.

In an embodiment, a method of producing a multi-level RF signal includes producing plurality of pulse-width modulated signals based on an input signal. The method further includes driving a corresponding plurality of parallel amplifiers with the plurality of pulse-width modulated signals by setting a parallel amplifier to have a first output impedance when a corresponding pulse-width modulated signal is in an active state and setting the parallel amplifier to have a second output impedance when the corresponding pulse-width is in an inactive state. The method also includes phase shifting the outputs of the plurality of parallel amplifiers, wherein phase shifting transforms the second output impedance into a third impedance that is higher than the second output impedance, and combining the phase shifted outputs.

An ultra-wide band frequency modulator is disclosed. The frequency modulator includes a direct modulation phase lock loop that receives a small component. The frequency modulator also includes a delay module that produces a plurality of delay lines. The frequency modulator further includes an edge selector that receives a large component and the plurality of delay lines.

A communications device may include a near-field communication (NFC) circuit device, and a radio frequency (RF) signal blocking member adhesively coupled with the NFC device. The RF signal blocking member may be configured to block RF signal communication by the NFC device while coupled therewith. The RF signal blocking member may comprise an electrical conductor. In accordance with an example, the RF signal blocking member may comprise a frangible layer. In another example, a pressure sensitive adhesive layer may be included for adhesively securing the RF signal blocking member with the NFC device.

A radio frequency system includes a power amplifier that outputs a radio frequency signal to a matching network via a transmission line between the power amplifier and the matching network. A sensor monitors the radio frequency signal and generates first sensor signals based on the radio frequency signal. A distortion module determines a first distortion value according to at least one of (i) a sinusoidal function of the first sensor signals and (ii) a cross-correlation function of the first sensor signals. A first correction circuit (i) generates a first impedance tuning value based on the first distortion value and a first predetermined value, and (ii) provides feedforward control of impedance matching performed within the matching network including outputting the first impedance tuning value to one of the power amplifier and the matching network.

A passively torque-balanced device includes (a) a frame; (b) a drivetrain including a drive actuator mounted to the frame and configured for reciprocating displacement, an input platform configured for displacement by the drive actuator, a plurality of rigid links, including a proximate link and remote links, wherein the rigid links are collectively mounted to the frame, and a plurality of joints joining the rigid links and providing a plurality of non-fully actuated degrees of freedom for displacement of the rigid links, the plurality of joints including a fulcrum joint that is joined both to the input platform and to the proximate rigid link; and (c) at least two end effectors respectively coupled with the remote links and configured for displacement without full actuation.

An assembly for shielding an aircraft from electromagnetic energy may include a window mounting configured to be conductively coupled to an aperture in a fuselage of an aircraft. The window mounting may include a window pane having an electromagnetically-reflective coating for reflecting electromagnetic energy. The window pane may remain electrically isolated from the fuselage prior to the electromagnetic energy exceeding a frequency of approximately 1 GHz. The window mounting may further include a capacitive gasket capacitively coupling the window pane to the fuselage after the frequency of the electromagnetic energy reflected by the window pane exceeds approximately 1 GHz.

A wireless remote forms a two-way radiofrequency (RF) communication network with a winch control module that allows the wireless remote to control both the winch and additional vehicle accessories through the winch control module. Further accessory control modules allow the control of more accessories utilizing the wireless remote by way of RF communication. Feedback from either the winch control module or the accessory control module is sent back to the wireless remote to allow the operator to view the current operating conditions of the winch or accessories.

A seismic source array includes a first source and a second source. The first source has a first spectral output and the second source has a second spectral output different than the first spectral output. The first source has a first total volume different than a second total volume of the second source.

Systems and methods for optimizing low frequency output of marine sources are described. The marine source arrangements and associated methods disclosed herein seek to fully frequency lock bubbles emitted by airguns in close proximity to one another. In this manner, larger effective bubble volumes can be achieved, thus increasing low frequency output.

A method for processing a signal modulated with a variable carrier frequency includes calculating a coefficient for demodulation of the signal. The method also includes demodulating the signal by calculating discrete intermediate values utilizing the coefficient for a predefined maximum number of steps and calculating the signal with the aid of the intermediate values of the coefficient. The value of the coefficient is respectively calculated on the basis of carrier frequencies for each step.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and a relevant device, characterized in that the method comprises: generating a prefix according to a partial time-domain main body signal truncated from a time-domain main body signal; generating the hyper prefix according to the entirety or a portion of the partial time-domain main body signal; and generating time-domain symbol based on at least one of the cyclic prefix, the time-domain main body signal and the hyper prefix, the preamble symbol containing at least one of the time-domain symbols. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels; and generating a hyper prefix based on the entirety or a portion of the above truncated time-domain main body signal enables the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

A Bluetooth Low Energy (BLE) device, having a demodulator configured to translate in-phase and quadrature components of a received BLE signal into a differential phase signal; an estimator configured to estimate a frequency offset of the differential phase signal; and a detector configured to detect information in the differential phase signal corrected by the estimated frequency offset.

It is proposed a method for delay spread classification of an orthogonal frequency-division multiplexing signal (multiplexing signal), and a receiving device and a telecommunication device connected thereto, the multiplexing signal comprising at least a first multiplexing symbol comprising at least two first reference symbols in the frequency domain, the method comprising: receiving at least the first multiplexing symbol; demodulating at least the first reference symbols of the first multiplexing symbol; determining at least a first autocorrelation value by autocorrelating the demodulated first reference symbols in the frequency domain; computing the filtered output energy of the autocorrelation and classifying the delay spread by mapping the ratio of the output energy for the filters.

A device set in a multimedia cable network includes a first modem including a first module to receive a beacon. The first modem has a first frequency and the beacon has a second frequency. When the first frequency of the first modem is not available, the first modem checks whether the second frequency is available in the multimedia cable network.

Wireless strain and displacement sensors wirelessly monitor structural health and integrity, and are made by printing inductor-interdigital capacitor sensing circuits on a variety of substrates, including ceramic substrates, with thermally processable conductive inks. Sensors of the invention can be employed to detect strain and displacement of civil structures, such as bridges and buildings. The sensors include sensing elements that are mounted or printed on stiff, inflexible substrates, which prevent the sensing elements from bending, stretching, or otherwise warping when the sensor is strained. An interlayer between the sensing elements allows the sensing elements to move with respect to each other during application of strain. Thus, strain causes the sensing elements to move but not to deform, causing changes in sensor resonance that can be detected through wireless radio-frequency interrogation. Because the sensing elements do not change shape when under strain, the sensor can undergo millions of measurement cycles before breaking.

This disclosure describes methods, devices, and systems related to an OFDMA Distributed Channel Access. Devices are disclosed comprising: at least one processor; and at least one memory that stores computer-executable instructions, wherein the at least one processor is configured to access the at least one memory and execute the computer-executable instructions to identify a trigger frame received on the communication channel from the computing device. The at least one processor may determine an uplink frame to be sent to a computing device on a communication channel. The at least one processor may identify one or more random access resource allocations, wherein the one or more random access resource allocations are associated with the trigger frame. The at least one processor may assign a respective numerical value to each of the one or more random access resource allocations. The at least one processor may also select a numerical value based at least in part on a probability distribution. The at least one processor may also determine a particular resource allocation of the one or more random access resource allocations that corresponds to the numerical value. The at least one processor may also cause the uplink frame to be sent to the computing device using the particular resource allocation.

A system, apparatus and method is disclosed for multiband wireless communication. Frequency bands and/or transmission formats are identified as available within a range for wireless communication. The system evaluates signal quality metrics for each frequency band and selects a communication method based on the evaluation. Multiple frequency bands and communication methods can be utilized by the system such that a combination of licensed, unlicensed, semilicensed, and overlapped frequency bands can be simultaneously used for communication. The system monitors communications and can report link performance for adaptive control of the selected communication methods.

Embodiments of the present invention disclose a wireless access point, including: a first radio frequency module, a second radio frequency module, and a processor. A frequency band of the first radio frequency module is the same as that of the second radio frequency module; the first radio frequency module and the second radio frequency module work on different channels; a first transmit power upper limit of the first radio frequency module is greater than a second transmit power upper limit of the second radio frequency module; and the processor is configured to schedule a terminal whose signal strength is greater than a threshold to associate with the wireless access point by using the second radio frequency module. The complexity of hardware design for integrating two radio frequency modules of a same frequency band into one AP may be reduced.

A torsional vibration damper assembly for a hydrokinetic torque coupling device, comprises a torsional vibration damper, and a dynamic absorber operatively connected to the torsional vibration damper. The torsional vibration damper comprises a driven member rotatable about a rotational axis, a first retainer plate rotatable relative to the driven member coaxially with the rotational axis, and a plurality of damper elastic members interposed between the first retainer plate and the driven member. The damper elastic members elastically couples the first retainer plate to the driven member. The dynamic absorber includes an inertial member. The inertial member is mounted to the torsional vibration damper rotatably relative to the driven member. The inertial member is rotationally guided and centered relative to the rotational axis by the driven member of the torsional vibration damper.

An integrated circuit includes a drive circuit with a first inverter circuit with a first transistor of a first conductivity type and a second transistor of a second conductivity type. The drains of the first and second transistors are connected. An output circuit is provided having a third transistor of the second conductivity with a gate connected to the drains of the first and second transistors. A capacitor is connected between the gate and a drain of the third transistor and has a capacitance greater than 0.5 pF and less than or equal to 3.0 pF. A gate width of the first transistor when divided by a gate width of the third transistor has a value of less than 1/100. The output circuit is configured to output a transmission signal from the drain of the third transistor.

Described is an apparatus comprising: a first phase frequency detector (PFD) to determine a coarse phase difference between a first clock signal and a second clock signal, the first PFD to generate a first output indicating the coarse phase difference; and a second PFD, coupled to the first PFD, to determine a fine phase difference between the first clock signal and the second clock signal, the second PFD to generate a second output indicating the fine phase difference.

A double frequency-shift keying modulating device includes a modulation module. The modulation module receives an oscillating signal and a digital signal, and generates a modulation output signal that has a first frequency. The first frequency is associated with a frequency of the oscillating signal and varies periodically at a second frequency. The second frequency is associated with the digital signal and the frequency of the oscillating signal.

A radio-frequency (RF) switch includes a field-effect transistor (FET) disposed between a first node and a second node, the FET having a source, a drain, a gate, and a body. The RF switch further includes a coupling circuit including a first path and a second path, the first path being connected between the gate and one of the source or the drain via a first resistor in series with a first capacitor, the second path being connected between the body and the one of the source or the drain via a second resistor in series with a second capacitor, the coupling circuit configured to allow discharge of interface charge from either or both of the gate and body.

A system, method, and device for improving the functioning of security tags for use with merchandise are provided. A security tag device, to be used in conjunction with a tag monitoring device, may be provided with a product. The product may be conductive or may have metallic packaging. The security tag may include a planar dielectric substrate having a first side and an opposing side. An electronic article surveillance (EAS) circuit may be placed on the first side of the planar dielectric substrate. A ferrite sheet having a first side and an opposing side may be coupled to the opposing side of the planar dielectric substrate. A metal backing sheet may be coupled to the opposing side of the ferrite sheet. The planar dielectric substrate may be centered or offset on the ferrite sheet and the ferrite sheet may be centered or offset on the metal backing sheet.

A printed circuit board includes a substrate including a surface layer and a first ground layer; a high-frequency signal generation part provided in the surface layer of the substrate; at least one high-frequency signal connector mounting portion formed in the surface layer of the substrate; at least one high-frequency signal line formed in the surface layer of the substrate, and extend from the high-frequency signal generation part to the at least one high-frequency signal connector mounting portion; and at least one high-frequency signal connector disposed in the at least one high-frequency signal connector mounting portion, wherein an end of the first ground layer is exposed to a side surface of the substrate, and when the high-frequency signal connector is disposed in the at least one high-frequency signal connector mounting portion, a ground of the high-frequency signal connector is in contact with the end of the first ground layer.

Previously available elastomeric EMI gaskets provided for multiport RF connector assemblies have performance limiting drawbacks. Consequently, EM isolation provided by a previously available elastomeric EMI gasket is often inadequate. Various implementations disclosed herein include multiport RF connection arrangements that use a metal gasket arranged within at least a portion of an isolation space provided by a multiport RF connector. In some implementations, a multiport connection arrangement includes a substrate, a multiport RF connector and a fitted metal gasket. The substrate includes a first surface and a first plurality of connection ports. The multiport connector has a body that includes a second surface, a second plurality of connection ports, and includes an electromagnetic isolation boundary that defines an isolation space between at least two of the second plurality of connection ports terminating at the second surface. Mechanical fasteners are optional and are included to merely provide engagement, without substantial compressive force.

In one embodiment, a radio altimeter tracking filter is provided. The filter comprises: a wireless radio interface; a processor coupled to the wireless radio interface; a memory coupled to the wireless radio interface; wherein the wireless radio interface is configured to wirelessly receive a radio altimeter signal and convert the radio altimeter signal to a baseband frequency signal, wherein the a radio altimeter signal sweeps across a first frequency spectrum between a first frequency and a second frequency; wherein the processor is configured to pass the baseband frequency signal through a filter executed by the processor, the filter comprising a passband having a first bandwidth, and wherein the filter outputs a plurality of spectral chirps in response to the baseband frequency signal passing through the first bandwidth; wherein the processor is configured to process the plurality of spectral chirps to output characteristic parameters that characterize the radio altimeter signal.

A flash analog-to-digital converter (ADC) includes comparators that convert an analog input signal to a digital output signal. Offsets of these comparators introduce noise and can hurt the performance of the ADC. Thus, these comparators are calibrated using calibration codes. Conventional calibration methods determine these calibration codes by removing the ADC from an input signal. Otherwise, it is difficult to distinguish the noise from the signal in the calibration measurement. In contrast, an embodiment can determine the calibration codes while the ADC converts the input signal to a digital signal. Such an embodiment can be achieved by a frequency-domain technique. In an embodiment employing a frequency-domain power meter, an input signal can be removed from the power measurement. This removal enables accurate measurement of in-band noise without having the measurement be corrupted by input signal power.

A device comprising: a receive antenna configured to receive a first radio-frequency (RF) signal having a first center frequency; a first transmit antenna configured to transmit a second RF signal having a second center frequency that is a harmonic of the first center frequency; a second transmit antenna configured to transmit a third RF signal having a third center frequency that is a harmonic of the first center frequency and is different from the second center frequency; first circuitry, coupled to the receive antenna and to the first transmit antenna, configured to generate the second RF signal using the first RF signal and provide it to the first transmit antenna for transmission; and second circuitry, coupled to the receive antenna and to the second transmit antenna, configured to generate the third RF signal using the first RF signal and provide it to the second transmit antenna for transmission.

The present invention relates to a resonant frequency tunable antenna, and may provide a resonant frequency tunable antenna which comprises: a first ground part; a power supply part connected in the longitudinal direction of the antenna from the first power supply part; and a second ground part connected in the longitudinal direction of the antenna from the power supply part, wherein the second ground part is a variable ground part, the second ground part and the power supply part are connected by a switch, and the switch is connected to a common terminal which is grounded, so that the second ground part and the power supply part are linked and controlled.

A tracking antenna system for discrete radio frequency spectrums includes a reflector, a pedestal supporting the reflector, a radome assembly enclosing both, a first feed for gathering radio waves within a first of discrete RF spectrums that is removably disposed in front of the reflector at the focal point, a first RF module operably connected to the first feed for converting the first gathered radio waves to first electronic signals, a feed mount for removably supporting the first feed and configured to removably support a second feed for gathering radio waves within a second of discrete RF spectrums, and a module mount for removably supporting the first RF module and configured to removably support a second RF module for converting the second radio waves to second electronic signals. A method of using the tracking antenna system adaptable for discrete radio frequency spectrums is also disclosed.

A method for determining a position of an RF coil in a magnetic resonance imaging (MRI) system is disclosed. As an example, a center of a field of view (FOV) to be scanned may be adjusted to a magnetic field center of an MRI system, and coordinate values in a coordinate system for shape-characteristic points of the FOV may be determined, where an origin of the coordinate system is located at the magnetic field center of the MRI system. A preset gradient magnetic field may be applied to the FOV, and coil units respectively covering the shape-characteristic points may be determined. An effective region may be obtained by connecting the determined coil units according to the shape of the FOV, and a coil unit located in the effective region may be determined as an effective coil unit for imaging the FOV by the MRI system.

Methods and systems for frequency-dependent fluid attenuation measurement are provided. In certain embodiments, the methods comprise: generating one or more reference acoustic signals within a reference fluid; receiving one or more reference acoustic signal reflections; determining a frequency-dependent response function based, at least in part, on the one or more reference acoustic signal reflections; generating one or more sample acoustic signals within a sample fluid; receiving one or more sample acoustic signal reflections; and determining a frequency-dependent attenuation function of the sample fluid based, at least in part, on the one or more sample acoustic signal reflections and the frequency-dependent response function.

Disclosed are improved methods and structures for actively stabilizing the oscillation frequency of a trapped ion by noninvasively sampling and rectifying the high voltage RF potential at circuit locations between a step-up transformer and a vacuum feedthrough leading to the ion trap electrodes. We use this sampled/rectified signal in a feedback loop to regulate the RF input amplitude to the circuit. By employing techniques and structures according to the present disclosure we are advantageously able to stabilize a 1 MHz trapped ion oscillation frequency to

In an example arrangement an apparatus includes a semiconductor substrate having a front side surface including circuitry and a backside surface opposing the front side surface; a plurality of metal conductors formed over a front side surface of the semiconductor substrate; at least one cavity opening etched in a backside surface of the semiconductor substrate; and a radiator formed in a portion of the metal conductors and configured to radiate signals through the cavity opening in the backside surface. Methods and additional apparatus arrangements are also disclosed.

While China's demand for Australian rock lobster soars, less international flights causes product delivery to be capped.

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(University of Warwick) Warm winter spells have increased in frequency and duration two- to three times over since 1878, according to scientists led by the University of Warwick.

We propose a novel estimation procedure for scale-by-scale lead-lag relationships of financial assets observed at high-frequency in a non-synchronous manner. The proposed estimation procedure does not require any interpolation processing of original datasets and is applicable to those with highest time resolution available. Consistency of the proposed estimators is shown under the continuous-time framework that has been developed in our previous work Hayashi and Koike (2018). An empirical application to a quote dataset of the NASDAQ-100 assets identifies two types of lead-lag relationships at different time scales.

Current explanation techniques towards a transparent Convolutional Neural Network (CNN) mainly focuses on building connections between the human-understandable input features with models' prediction, overlooking an alternative representation of the input, the frequency components decomposition. In this work, we present an analysis of the connection between the distribution of frequency components in the input dataset and the reasoning process the model learns from the data. We further provide quantification analysis about the contribution of different frequency components toward the model's prediction. We show that the vulnerability of the model against tiny distortions is a result of the model is relying on the high-frequency features, the target features of the adversarial (black and white-box) attackers, to make the prediction. We further show that if the model develops stronger association between the low-frequency component with true labels, the model is more robust, which is the explanation of why adversarially trained models are more robust against tiny distortions.

Piotr Kokoszka, Neda Mohammadi Jouzdani.

Source: Bernoulli, Volume 26, Number 3, 2383--2399.

Abstract:
This paper is concerned with frequency domain theory for functional time series, which are temporally dependent sequences of functions in a Hilbert space. We consider a variance decomposition, which is more suitable for such a data structure than the variance decomposition based on the Karhunen–Loéve expansion. The decomposition we study uses eigenvalues of spectral density operators, which are functional analogs of the spectral density of a stationary scalar time series. We propose estimators of the variance components and derive convergence rates for their mean square error as well as their asymptotic normality. The latter is derived from a frequency domain invariance principle for the estimators of the spectral density operators. This principle is established for a broad class of linear time series models. It is a main contribution of the paper.

Bank of Italy Working Papers by Andrea Gazzani and Alejandro Vicondoa

Bank of Finland Research Discussion Papers by Gonçalo Faria and Fabio Verona

The American Academy of Pediatrics recommends routine alcohol screening for all adolescents. Problem-based substance use screens for adolescents exist, but have limitations. A consumption-based alcohol screen could provide an empirically validated, very brief method to screen youth for alcohol-related problems.

National sample data indicate that frequency of alcohol use has high sensitivity and specificity in identifying youth with alcohol-related problems. A range of age-specific frequency cut scores perform well; specific cut points can be selected based on the screening context. (Read the full article)