11740 results about "Frequency changer" patented technology

An apparatus and method of wirelessly sharing power by an inductive method are provided. The apparatus includes a first battery supplying power; a rectifier supplied with an AC voltage, converts the AC voltage into a DC voltage, and outputs the DC voltage; an inverter supplied with the DC voltage, converts the DC voltage into the AC voltage, and outputs the AC voltage; a power control/conversion unit connected to the rectifier or the inverter and supplying power to charge the first battery or a second battery that is provided in an external device as a power supply for the first battery; and a communication unit communicating with the external device.

Methods and systems for producing a change in a medium. A first method and system (1) place in a vicinity of the medium at least one upconverter including a gas for plasma ignition, with the upconverter being configured, upon exposure to initiation energy, to generate light for emission into the medium, and (2) apply the initiation energy from an energy source including the first wavelength λ₁ to the medium, wherein the emitted light directly or indirectly produces the change in the medium. A second method and system (1) place in a vicinity of the medium an agent receptive to microwave radiation or radiofrequency radiation, and (2) apply as an initiation energy the microwave radiation or radiofrequency radiation by which the agent directly or indirectly generates emitted light in the infrared, visible, or ultraviolet range to produce at least one of physical and biological changes in the medium.

The invention is directed to controlling an electric motor by means of a frequency converter. The frequency converter can be connected to one of several different mains voltages. According to the present invention, the maximum output power of the frequency converter, is limited when the actual mains voltage is lower than the maximum nominal mains voltage, for which the frequency converter is designed, and during the limitation the frequency converter controls the speed of the motor within a power range up to a limited maximum output power. This gives a genuine multi-voltage unit, which can be connected to a wide range of mains voltages.

Disclosed is an all-optical frequency upconverter in a radio-over-fiber system that outputs upconverted optical radio frequency (RF) signals using an optical intermediate frequency signal and an optical local oscillation signal. The all-optical frequency upconverter includes a semiconductor optical amplifier that mixes the optical intermediate frequency signal with the optical local oscillation signal through four wave mixing, and an optical filter that filters a plurality of frequency component signals, which are generated through the four wave mixing, to extract optical RF signals. According to the invention the system configuration can be made simple, and wide LO and IF frequency bandwidths can be provided.

The invention discloses an electric drive fracturing semi-trailer of a frequency conversion integrated machine. The optimization and integration of the traditional power supply semi-trailer and the fracturing semi-trailer realize the functions of power supply and fracturing of one semi-trailer without using the complete set of the power supply semi-trailer and the fracturing semi-trailer, the electric drive fracturing semi-trailer is more flexible in actual use, and the well field layout of oil and gas fields is greatly optimized; the transportation is convenient; only a set of high-voltage cables can be connected with the high-voltage power supply to reach a working state, and the wiring installation is faster; compared with diesel-driven fracturing, and the noise of the electric drive fracturing is low without exhaust emission pollution; the driving source is power, which has lower cost than the diesel; the electric drive fracturing semi-trailer adopts an integrated design of a motorand a frequency converter (namely, the frequency conversion integrated machine), the space occupied by the electric motor and the inverter in the prior art is reduced effectively, so the installing part of the electric drive fracturing semi-trailer has smaller volume and the transportation is more convenient, and can also provide space guarantee for installing other equipment on the semi-trailerbody.

A feedback compensation detector for a direct conversion transmitter includes a baseband processor, a direct up-converter, an antenna, and an impairment detection and compensation feedback circuit. The baseband processor generates an in-phase (I) baseband signal and a quadrature-phase (Q) baseband signal. The direct up-converter is coupled to the baseband processor, and combines the I and Q baseband signals with an RF carrier signal to generate an RF output signal. The antenna is coupled to the direct up-converter, and transmits the RF output signal. The impairment detection and compensation feedback circuit is coupled to the RF output signal and the I and Q baseband signals. The impairment detection and compensation feedback circuit down-converts the RF output signal to generate an intermediate frequency (IF) signal, measures as least one signal impairment in the IF signal, and pre-distorts the I and Q baseband signals to compensate for the measured signal impairment.

Systems and methods for receiving MIMO signals for testing and analyzing operation of MIMO communications devices. Examples of systems and/or methods for receiving MIMO signals include a measuring receiver with N RF paths consisting of N downconverters. Each downconverter achieves a frequency shift of the input MIMO signal equal to a shifting frequency of a first intermediate frequency (IF) plus a delta determined by the signal bandwidth multiplied by an integer number between 1 and N. The shifted N MIMO signals are combined to generate one combined analog MIMO signal. An analog to digital converter converts the combined analog MIMO signal to a stream of digital samples where the samples may be tested and analyzed with metrics on signals communicated in a MIMO environment. Example systems and method for receiving MIMO signals may also be implemented as a MIMO channel emulator such that samples generated by the ADC may be upconverted to output copies of the original signals to a receiver DUT, for example.

Agile frequency converter and method, IF-RF level exchange process, and notch filtering techniques. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. Converter employs two-stage frequency conversion process, with gain exchange system using variable pre-mixer gain and variable post-mixer attenuation to maintain constant RF output signal power level. For those few conversion frequencies where distortion component(s) cannot be filtered without degrading desired signal, IF-RF level exchange is optimized for meeting the carrier-to-distortion (C/D) ratio specifications at slight expense of noise level for that channel only, while still meeting aggregate combined carrier-to-noise (C/N) specification requirements. Optimal apportionment of level exchange for each channel depends on specific frequency rejection capability of spurious components and is matched to filtering capability and stored within non-volatile memory of a microcontroller used in the frequency converter.

A transmitter chain has a quadrature modulator, a variable gain amplifier, an up-converter, and a variable gain power amplifier. An overall phase of the transmitter chain is adjusted on the basis of pre-stored phase information reflecting phase changes due to simultaneous gain changes of gains of at least the variable gain amplifier and the variable gain power amplifier.

The invention discloses a frequency-change radar goal emulator of millimeter wave, which comprises the following parts: control unit, transceiver unit, Doppler analog unit, distant analog unit and amplitude analog unit, wherein the radar signal enters into the Doppler analog unit through transceiver unit, which produces middle-frequency signal through lower frequency-changer and low-pass filter of the Doppler analog unit; the upper frequency-changer and band-pass filter group of Doppler analog unit produces RF signal; the difference of local oscillator frequency of upper and lower frequency-changers analogs the Doppler frequency shift of goal; the RF signal generates launching signal through changing the echo amplitude of goal simulated by amplitude analog unit, which is transmitted by transceiver unit; the control unit transmits control signal for other four units according to the analog parameter such as input distance, speed and amplitude; the radar signal passes the emulator to provide an analog signal with Doppler frequency shift, signal amplitude fluctuation and distant delay to radar, which provides estimating platform for working property testing for radar.

The invention relates to a method for intelligently controlling the frequency of a variable-frequency air-conditioner, comprising the following steps of: (1) reading the temperature difference delta T of the set temperature of the variable-frequency air-conditioner and indoor ambient temperature and calculating a frequency value Ft according to the temperature difference by a frequency converter;(2) reading each running parameter of the variable-frequency air-conditioner and controlling the air-conditioner to stop, or limit the frequency, or reduce the frequency or normally run according to the parameter value by using the frequency converter; (3) if each parameter displays that the frequency needs to be limited, ensuring the adjusted frequency Fobj to be equal to Ft, and if each parameter displays that the frequency needs to be reduced, ensuring the Fobj to be equal to Ft-delta T; (4) if each parameter displays the normal running, adjusting the frequency Ft according to the variation of the delta T in a certain time t1; and (5) outputting the Fobj to a driver of a variable-frequency compressor of the air-conditioner by using the frequency converter. The method can improve the comfort level, the using effect and the service life of the variable-frequency air-conditioner.

The disclosed invention provides apparatus and methods that can convert frequencies of time-encoded signals. In one aspect, a down-converter circuit includes low-pass filters, a switch, a time encoder, and an output low-pass filter. In another aspect, an up-converter circuit includes an analog or digital input time encoder, low-pass filters, a switch, an output time encoder, and a time-encoded band-pass filter. In yet another aspect, a complete receiver system is provided. The receiver system can operate effectively with signals in the radio frequency range.

A motor control device includes a current detecting portion that detects phase current of one phase among three phase currents supplied from an inverter to a motor, and a current estimator that estimates phase current of phases other than the detected phase current by using a specified current value indicating current to be supplied to the motor, and derives control current corresponding to the specified current value from the estimated phase current and the phase current of one phase. The motor control device controls the motor via the inverter so that the control current follows the specified current value.

A communications satellite (201) has an on-board high speed packet switch for switching transmitted data packets. The packet switch (502) is part of a processor subsystem (501) which also includes a number of demodulators (5031 to 503n) demodulating signals received from an uplink downconverter. All of the processors in the processor subsystem (501) are organized into a loosely coupled, distributed, architecture of general purpose computer modules (601) and digital signal processor modules (602) having both primary and redundant processors and being connected to each other by dual redundant PCI buses. Software and firmware is layered and distributed redundantly over the processor modules (601, 602).

A vehicle includes a motor for driving wheels WH, an inverter to drive the motor, and a control device to perform PWM control of the inverter. The control device performs synchronous PWM control in a case where an electric current supplied to the motor by the inverter or torque generated in the motor is larger than a threshold value; and performs the synchronous PWM control or non-synchronous PWM control in a case where the electric current or the torque is smaller than the threshold value and sets carrier frequency or a pulse number of the PWM control to be higher than the case where the electric current or the torque is larger than the threshold value. Thereby, it is possible to provide a vehicle of achieving reduction of noise, reduction of cost and improvement of fuel consumption in a balanced manner.

Systems and methods for combining signals from multiple active wireless receivers are discussed herein. An exemplary system comprises a first downconverter, a phase comparator, a phase adjuster, and a second downconverter. The first downconverter may be configured to downconvert a received signal from a first antenna to an intermediate frequency to create an intermediate frequency signal. The phase comparator may be configured to mix the received signal and a downconverted signal to create a mixed signal, compare a phase of the mixed signal to a predetermined phase, and generate a phase control signal based on the comparison, the downconverted signal being associated with the received signal from the first antenna. The phase adjuster may be configured to alter the phase of the intermediate frequency signal based on the phase control signal. The second downconverter may be configured to downconvert the phase-shifted intermediate frequency signal to create an output signal.

A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.