9746 results about "Frequency modulation" patented technology

FDPM processing provides an amplitude signal and a phase signal at a modulation frequency to improve measurement fidelity during measurement of one or more blood parameters. In an embodiment, a light source modulates light at a modulation frequency around 200 MHz to produce an amplitude and phase plethysmograph, usable to access clinical test data.

A power transmission method used in a high-power wireless induction power supply system consisting of a power-supplying module and a power-receiving module is disclosed. The power-supplying module regulates its output energy by means of frequency modulation and driving power adjustment, enabling the energy to be received by the power-receiving module and transmitted through a power-receiving coil array and a primary resonant capacitor and a secondary resonant capacitor of power-receiving resonance circuit, a synchronizing rectifier, a low-power voltage stabilizer, a high-frequency filter capacitor, a first power switch, a low-frequency filter capacitor and a second power switch of a filter circuit for output to an external apparatus.

A frequency modulation type wireless power supply and charger system includes a power supply base unit consisting of a first microprocessor, a power circuit, a power switch driver circuit, a first resonant circuit, a first coil, a detection module and a power input interface, and a wireless power supply and charge receiver unit consisting of a secondary coil, a second resonant circuit, a rectifier filter circuit, a detection and protection module, a second microprocessor, a temperature sensor, a charging module and a power output interface and adapted for receiving electrical power from the power supply base unit wirelessly for charging an external electronic device. The detection and protection module of the wireless power supply and charge receiver unit detects the supply of the electrical power, and the second microprocessor sends a feedback signal to the power supply base unit through the signal generator circuit and the second resonant circuit subject to the detection of the detection and protection module for enabling the power supply base unit to control the power switch driver circuit to regulate its output power automatically, thereby minimizing power transmission loss and the load of the internal components of the wireless power supply and charge receiver unit.

A novel apparatus and method for a hybrid Cartesian / polar digital QAM modulator. The hybrid technique of the present invention utilizes a combination of an all digital phase locked loop (ADPLL) that features a wideband frequency modulation capability and a digitally controlled power amplifier (DPA) that features interpolation between 90 degree spaced quadrature phases. This structure is capable of performing either a polar operation or a Cartesian operation and can dynamically switch between them depending on the instantaneous value of a metric measured by a thresholder / router. In this manner, the disadvantages of each modulation technique are avoided while the benefits of each are exploited.

A method is provided for communicating signals at a low power level in an electromagnetic interference (EMI) environment. A first device transmits a modulated signal having a first carrier frequency, including the encoded information via a hardwire transmission medium. In one aspect, the power level of the modulated signal can be adjusted to minimize power consumption or reduce the generation of EMI. The modulated signal may be in one of the following formats: frequency modulation (FM) or phase modulation (PM) to name a few examples. A second device including a logarithmic detector amplifier (LDA) demodulator circuit receives the signal, which may be mixed with EMI. The LDA demodulator circuit amplifies the modulated signal, without amplifying the EMI, to supply a demodulated baseband signal, which may be an n-ary digital signal, or an audio signal. A low-power, noise insensitive communication channel is also provided.

Described are apparatus and methods for electrically modulating a nerve in a mammal. An electrical signal that includes a signal intensity pattern and a signal frequency pattern is delivered to a nerve. The combination of the signal intensity pattern and the signal frequency pattern is effective to result in weight loss, fat loss, and / or lean-mass gain, in a mammal. In some embodiments the nerve is modulated in response to a physiological parameter. In some embodiments, the physiological parameter is measured by a sensor.

A personal monitoring device has a sensor assembly configured to sense physiological signals upon contact with a user's skin. The sensor assembly produces electrical signals representing the sensed physiological signals. A converter assembly, integrated with, and electrically connected to the sensor assembly, converts the electrical signals generated by the sensor assembly to a frequency modulated inaudible ultrasonic sound signal. The ultrasonic signal is demodulated from an aliased signal produced by undersampling.

A control circuit for a lighting system allows analog control over a first range of illumination intensities in which the intensity of the illumination source varies in proportion to the voltage level of the control signal. The circuit provides for improved dimming and color mixing capability by allowing pulse width or frequency modulation control in addition to analog control over a second range of illumination intensities.

Disclosed is a system and method for providing an oscillating signal of relatively precise frequency without using a signal provided by a crystal as a reference. Disclosed is a feedback oscillator circuit configured to output an oscillating signal having a frequency defined by a reference signal. The oscillating signal can be sent to one or more circuits including at least one frequency sensitive element. The frequency sensitive element produces an output signal which depends on the frequency of the oscillating signal. A controller controls the reference signal in order to cause an attribute of the output signal to have a value within a desired range.

An apparatus and method for using ultrasound augmented with microbubbles, thrombolytic drugs or other agents for clot lysis wherein at least one ultrasound transducer generates a plurality of acoustic signals and time, amplitude, phase and frequency modulation of the signals provide more uniform power delivery with fewer gaps in the ultrasound field. Interference patterns from one or multiple transducers are constantly shifted in position. A phased array of transducers may generate a beam that is swept over the area to be treated. In another embodiment, an array of transducers may generate ultrasound at a number of slightly varying frequencies to produce an interference pattern that sweeps in and out through the targeted tissue. A single array may be used to produce both effects simultaneously or separately.

Described are apparatus and methods for electrically modulating a nerve in a mammal. An electrical signal that includes a signal intensity pattern and a signal frequency pattern is delivered to a nerve. The combination of the signal intensity pattern and the signal frequency pattern is effective to result in weight loss, fat loss, and / or lean-mass gain, in a mammal. In some embodiments the nerve is modulated in response to a physiological parameter. In some embodiments, the physiological parameter is measured by a sensor.

A novel mechanism for simultaneous multiple signal reception and transmission using frequency multiplexing and shared processing. Multiple RF signals, which may be of various wireless standards, are received using one or more shared processing blocks thereby significantly reducing chip space and power requirements. Shared components include local oscillators, analog to digital converters, digital RX processing and digital baseband processing. In operation, multiple RX front end circuits, one for each desired wireless signal, generate a plurality of IF signals that are frequency multiplexed and combined to create a single combined IF signal. The combined IF signal is processed by a shared processing block. Digital baseband processing is performed on each receive signal to generate respective data outputs. Further, simultaneous full-duplex transmission and reception is performed using a single local oscillator. The phase / frequency modulation of the frequency synthesizer used in the TX is removed from the local oscillator signal for use in the receiver.

An optical fiber scanner is used for multiphoton excitation imaging, optical coherence tomography, or for confocal imaging in which transverse scans are carried out at a plurality of successively different depths within tissue. The optical fiber scanner is implemented as a scanning endoscope using a cantilevered optical fiber that is driven into resonance or near resonance by an actuator. The actuator is energized with drive signals that cause the optical fiber to scan in a desired pattern at successively different depths as the depth of the focal point is changed. Various techniques can be employed for depth focus tracking at a rate that is much slower than the transverse scanning carried out by the vibrating optical fiber. The optical fiber scanner can be used for confocal imaging, multiphoton fluorescence imaging, nonlinear harmonic generation imaging, or in an OCT system that includes a phase or frequency modulator and delay line.

A personal monitoring device has a sensor assembly configured to sense physiological signals upon contact with a user's skin. The sensor assembly produces electrical signals representing the sensed physiological signals. A converter assembly, integrated with, and electrically connected to the sensor assembly, converts the electrical signals generated by the sensor assembly to a frequency modulated inaudible ultrasonic sound signal. The ultrasonic signal is demodulated from an aliased signal produced by undersampling.

An ultrasonic surgical dissection system and method that employs an ultrasonic waveform that provides improved dissection of tissue while simultaneously providing improved hemostasis is disclosed. The disclosed system provides an ultrasonic waveform that includes a carrier frequency that may be pulse modulated at a predetermined rate and / or duty cycle. Embodiments are presented wherein the disclosed system provides an ultrasonic waveform having a frequency modulated carrier frequency. Additionally or alternatively, the disclosed waveform may be amplitude modulated. In yet another embodiment, an amplitude modulation of the ultrasonic signal may be synchronized, at least in part, with a frequency modulation of the ultrasonic signal. The frequency modulation and / or amplitude modulation may include continuously variable modulations and / or substantially instantaneous transitions between a first frequency and a second frequency and / or a first amplitude and a second amplitude.

Methods and apparatus are presented that reduce the overall system cost for automotive radar sensing applications through reduction of the number of the radar sensors required. In accordance with aspects of the present invention, one way sensor count reduction can be achieved is through the combination of target range, direction, and velocity determination capability with wide angular field of view coverage within a single sensor unit. One embodiment combines a transmit-pulsed, linearly stepped frequency modulated, transmit power limited radar architecture with a spatially separated receiver antenna array, intermediate frequency down-conversion, and a digital multi-zone monopulse (DMM) signal processing technique for high-resolution target range, velocity, and azimuth angle determination and fast update rate capability in a low cost, mass-production-capable design.

A personal monitoring device has a sensor assembly configured to sense physiological signals upon contact with a user's skin. The sensor assembly produces electrical signals representing the sensed physiological signals. A converter assembly, integrated with, and electrically connected to the sensor assembly, converts the electrical signals generated by the sensor assembly to a frequency modulated physiological audio signal having a carrier frequency in the range of from about 6 kHz to about 20 kHz.

The invention relates to a modular charging / discharging system of a power battery pack of a multifunctional electromobile, which aims to provide a system which can effectively meet the requirement for the bi-directional power transmission of a charging station and can exert the functions of peak clipping and valley filling as well as peak modulation and frequency modulation of a power grid. The technical scheme is as follows: the modular charging / discharging system of the power battery pack of the multifunctional electromobile comprises a charging-station monitoring system and an information management system, wherein the charging-station monitoring system is composed of a computer and a network communication system. The modular charging / discharging system is characterized by also comprising a three-phase step-down transformer, wherein the high voltage side of the three-phase step-down transformer is connected with a power grid, and the low voltage side of the three-phase step-down transformer is connected in parallel with a plurality of charging / discharging branches; each branch comprises a three-phase distribution transformer and a charging / discharging module, and the three-phase distribution transformer is connected in series with the charging / discharging module; and each charging / discharging module comprises a pulse-width modulation alternating current / direct current (PWM AC / DC) converter with the function of bi-directional power transmission, a plurality of electromagnetic isolation type DC / DC transform modules with the function of bi-directional power transmission and the information management system, and the electromagnetic isolation type DC / DC transform modules are connected in parallel.

A video processing engine terminates frequency-modulated video signals transported over the so-called third mile (the network segment from the head-end to the access network) for delivery to an end user. In various network architectures, these signals are received at a central office (CO), for the telephone companies; at a fiber node (FN), for MSOs; or at a satellite dish, for satellite networks. By terminating these signals appropriately, high-quality video service can be delivered efficiently to customers over the last mile. Systems and methods for processing these video streams as well as various network architectures that allow the network providers to offer cost effective video services to the mass market are described.

This invention discloses a valve that generates a hydraulic negative pressure pulse and a frequency modulator for the creation of a powerful, broadband swept impulse seismic signal at the drill bit during drilling operations. The signal can be received at monitoring points on the surface or underground locations using geophones. The time required for the seismic signal to travel from the source to the receiver directly and via reflections is used to calculate seismic velocity and other formation properties near the source and between the source and receiver. This information can be used for vertical seismic profiling of formations drilled, to check the location of the bit, or to detect the presence of abnormal pore pressure ahead of the bit. The hydraulic negative pressure pulse can also be used to enhance drilling and production of wells.

Binary and Quadrature Feher's Modulation (F-Modulation, or FMOD) Transmitter-Receiver systems and circuits exhibit reduced envelope fluctuation and peak radiation, and increased efficiency. A subclass of these systems has a constant envelope. They advantageously provide lower power operation with improved performance including robust BER performance, and compatibility with both linearly and nonlinearly amplified narrow spectrum, and without disadvantages of conventional BPSK, DBPSK QPSK and pi / 4-QPSK. Feher's BPSK (FBPSK) is an improved efficiency transmitter which is compatible with conventional BPSK receivers. FBPSK modems are based on using quadrature structure where Q-channel data is inserted in quadrature with I-channel data for certain applications. The Q-channel data may be “offset” from the I-channel data by an amount selectable between zero and a specified time. Further improvement in the spectrum is attained using correlation between I and Q channels. FBPSK modem is shown to meet the IEEE 802.11 specified spectral direct sequence spread spectrum mask (−30 dB point) for wireless LAN, and leads to an output power gain of 6.5 dB over conventional BPSK modems. The cross-coupled quadrature FMOD structure is also suitable for continuous mode and for burst operated TDMA, FDMA, CDMA, WCDMA and CSMA Frequency Modulation Quadrature AM (QAM), QPSK and offset QPSK, as well as pi / 4-shifted QPSK modems / processors. Reduced modulation index Gaussian FSK (GFSK), multilevel FM and cross-coupled Quadrature Amplitude Modulated (QAM) transmitters and combinations of these modulations and corresponding coherent demodulators are disclosed. Controlled rise and fall time descriptions of burst operated systems are included.

The invention belongs to crossing field of computer vision and intelligent robots and discloses a variational mechanism-based large-area indoor scene reconstruction method. The method comprises the following steps: step 1, acquiring calibration parameters of a camera, and building an aberration correcting model; step 2, building a camera position and gesture depiction and camera projection model; step 3, utilizing an SFM-based monocular SFM (Space Frequency Modulation) algorithm to realize camera position and gesture estimation; step 4, building a variational mechanism-based depth map estimation model, and performing solving on the model; and step 5, building a key frame selection mechanism to realize three-dimensional scene renewal. According to the invention, an RGB (Red Green Blue) camera is adopted to acquire environmental data, and a variational mechanism-based depth map generation method is proposed through utilizing a high-precision monocular positioning algorithm, so that quick large-area indoor three-dimensional scene reconstruction is realized, and problems of three-dimensional reconstruction algorithm cost and real-time performance are effectively solved.

A radio-frequency surgical implement detection system detects surgical implements in a surgical wound during and at the completion of a surgical procedure. Surgical implements, including surgical sponges or laparotomy pads, gauze pads and metallic surgical instruments, are individually attached to a non battery-powered, encapsulated radio-frequency marker. The marker comprises an integrated chip having a burnt-in memory code, which is broadcast through an antenna using a modulated carrier frequency. The code is received by an interrogating antenna of a detector. The interrogating antenna provides a power pulse, which is received by the antenna of the radio-frequency marker. The power pulse charges a capacitor, which proves power for the read function, carrier frequency modulation function and broadcast function of the integrated chip, permitting each marker-containing implement to be specifically identified.

A patient monitor is configured to interrogate an implantable medical device (IMD) and receive data from the IMD in response to the interrogation. The data received from the IMD includes electrogram (EGM) data, which the patient monitor frequency modulates for transmission, in real-time, onto a conventional telephone line. The frequency modulated EGM data that is transmitted from the patient monitor may in turn be displayed, in real-time, at a remote monitoring station in response to commands provided by a remote (DTMF) signal from a receiving station.

An interconnected wireless RF HVAC (heating, ventilation, air conditioning) system and wireless RF security system, which are interconnected and communicate with each other through the use of a common wireless RF technology, including the same selected frequency, modulation and a set of common protocols. The RF wireless HVAC system includes wireless RF thermostats which can communicate with and control both the HVAC system and the security system, and the wireless RF security system includes wireless RF controls or keypads which can communicate with and control both the security system and the HVAC system. The universal RF infrastructure can be expanded to provide communication or control of additional user or manufacturer installed wireless RF devices or systems through the universal RF home infrastructure.

This invention generally relates to an optical filter for a fiber optic communication system. A coupled multi-cavity optical filter may be used, following a directly modulated laser source, and converts a partially frequency modulated signal into a substantially amplitude modulated signal. The optical filter may compensate for the dispersion in the fiber optic transmission medium and may also lock the wavelength of the laser source.

A novel apparatus for and a method of estimating, calibrating and tracking in real-time the gain of a radio frequency (RF) digitally controlled oscillator (DCO) in an all-digital phase locked loop (ADPLL). Precise setting of the inverse DCO gain in the ADPLL modulating path allows direct wideband frequency modulation that is independent of the ADPLL loop bandwidth. The gain calibration technique is based on a steepest descent iterative algorithm wherein the phase ADPLL error is sampled and correlated with the modulating data to generate a gradient. The gradient is then scaled and added to the current value of the DCO gain multiplier.

An acoustic agglomerator for agglomerating constituents in a fluid is provided. The acoustic agglomerator includes an area containing a fluid having constituents and an acoustic generator operable to generate a modulated acoustic field to enhance agglomeration of the constituents in the fluid. In one aspect the acoustic field is frequency modulated and in other aspects the acoustic field is amplitude modulated, while yet in other aspects the acoustic field is both frequency and amplitude modulated. A method for agglomerating constituents in a fluid is also provided. The method includes providing a fluid with a constituent and applying an acoustic field to the fluid. The method provides for modulating the acoustic field to cause the constituent to agglomerate.