11792 results about "Frequency changer" patented technology

An embodiment of the invention uses a predistortion correction signal to combination the modulated RF signal by an analog multiplier for linearization of power amplifiers having nonlinear characteristics such as those used in wireless RF transmitters. A predistortion controller comprises a plurality of down converters for retrieving both the ideal non-distorted information and the feedback distorted information, together with pre-stored digitally-indexed predistortion information stored, for example, in a look-up table. The digitally-indexed information models nonlinear characteristics of the high power amplifier, and is stored prior to processing of pre-compensation in the power amplifier. When the predistortion information is combined with the modulated RF signal in the analog multiplier, the result is a substantially linear information transmission from the power amplifier. In an embodiment of the system, the modulated RF input signal and the feedback signal from PA output are down-converted, respectively, by analog devices, such as mixers, after which the analog intermediate frequency (IF) signals are digitized by analog-to-digital converters for digital predistortion correction processing, followed by predistortion processing performed by, for example, a DSP or FPGA chip to generate a digital correction control signal, which is then converted to an analog signal by a digital-to-analog converter, followed by combining the analog correction signal with the RF modulated input signal to yield the input to the power amplifier.

An enhanced transmitter for wireless power transmission is disclosed. The transmitter may be able to transmit radio frequency (RF) waves or pockets of energy for charging or powering an electronic device. The transmitter may include antenna element arrangements for receiving RF waves from a plurality of wireless sources and process them using a dedicated RF integrated circuit (RFIC) and set of antenna elements for receiving RF input signals from a plurality of wireless power sources. A digital signal processor (DSP) may be used to control reception using the dedicated RFIC and antenna elements of reception and to control transmission of wireless power selecting the transmitting RFICs and configuration of antenna elements to send RF waves or pockets of energy to a wireless receiver. The frequency of RF waves received may be sampled through a down converter array and line addressing devices to send the signals received to a micro-controller including a proprietary algorithm which control switching and processing necessary for faster and enhanced wireless power transmission, thus improving transmission efficiency.

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.

The present invention provides a generalized frequency conversion system for a steam turbine generator unit. The system comprises at least a steam turbine (T) with an adjustable rotating speed, a water feeding pump (BFP), a generator (G), a speed increasing gearbox (GB), a variable frequency bus (a, c) and an auxiliary machine connected thereto. With a change in load of the unit, parameters of steam entering the steam turbine (T) and an extracted steam amount are correspondingly adjusted (changed), so that the rotating speed of the steam turbine (T) changes correspondingly; and thus the rotating speed of the water feeding pump (BFP) is changed through the speed increasing gearbox (GB) on the one hand, and the frequency of an alternating current outputted by the generator (G) is changed on the other hand. Other types of frequency converters do not need to be additionally provided. The system is simple, reliable, low in cost, and high in efficiency.

Radio system including mixer device and switching circuit and method having switching signal feedback control for enhanced dynamic range and performance. Radio apparatus including: local oscillator input port for receiving periodic sinusoidal local oscillator signal; drive circuit for generating a substantially square-wave two-voltage level switching signal including: phase splitter circuit, voltage potential isolation circuit, and square wave signal generation circuit; FET mixing device; input / output signal separation circuit; analog-to-digital converter; and feedback control circuit. Radio tuner apparatus including low-band signal processing circuit; high-band signal processing circuit including first mixer circuit operating as an up-frequency converter, amplifier circuit, second mixer circuit operating as a down-frequency converter, and feedback control circuit for adjusting a duty cycle of a mixer switching device; signal combining circuit and output processing circuit. Method for operating radio system, apparatus, and tuner. Method of operating switching circuit.

The invention discloses electrically-driven ultra-large-displacement well cementation equipment. The electrically-driven ultra-large-displacement well cementation equipment comprises a first loading body and a second loading body; an auxiliary motor, a main motor, a clear water module, a pumping module, a control module, a hydraulic module and a mixing module are fixedly loaded on the first loading body; and a frequency converter module is fixedly loaded on the second loading body. The electrically-driven ultra-large-displacement well cementation equipment has the beneficial effects that the main motor is adopted to drive a plunger pump, torque converters are reduced, the layout space of the whole vehicle is increased, the auxiliary motor is adopted to drive a whole vehicle hydraulic system, and the number of driving motors is reduced; the frequency converter module and the well cementation equipment are loaded separately, the loading requirement is lowered, the structure is simpler, the occupied space is reduced, one frequency converter module can supply power to all the modules on the multiple first loading bodies at the same time, and use is flexible; and the main motor, the auxiliary motor and the hydraulic heat dissipation device are intensively distributed on the front portion of the first loading body, wiring is simple, connection is convenient, heat dissipation of equipment is intensively achieved, scalding accidents of workers in the operation process are avoided, and operation safety is improved.

A tracking and control method for the hybridded maximum power point of the photovoltaic pumping system. It contains: a, the check and choice logo, it will turn to the step b if it is ture, or it will turn to the step d. b, the output frequency of the inverter will be adjusted the running of the multiple criteria. C, the choice logo will become untrue and the reference voltage Verf=V (n), and the real running time of the normal voltage method, tCV, will be reset, and turn to the step a, or turn to the step a. d, the output frequency of the inverter will be adjusted by the running of the normal voltage method. e, To add a control cycle into the running time of the normal voltage method, tvc, the choice logo will be true if the tvc >= TVC and turn to the step a, or it will turn directly to the step a. it adjust the output frequency by the alternative running of multiple criteria and normal voltage, it can adjust the output frequency in time and control the DC voltage effectively and assure the stable running of the system, the system owns rapid and dynamic tracking characteristics, and a good stable characteristics by taking advantage of this method .

The present invention is a hybrid RF-digital signal processor-based filter for multiband radio architectures systems capable of spectrum re-farming and software defined radios. It performs low-loss frequency agile multiple notch filtering at RF where a large dynamic range exists at a filter input between signals in a stopband and passband. It is a frequency dependent signal attenuation apparatus having two paths connected together by directional couplers. The first path comprising a component such as a delay component or duplexer. The second path comprising a bandstop filter connected to a down converter, a digital filter, and an up converter. At the output of a power amplifier, the invention can be used to attenuate spurs, or noise within bands with strict emission constraints. At the input of a low noise amplifier, the invention can be used to attenuate blockers and transmitter noise outside of the receiver passband.

A semiconductor device that includes a clock generator which generates a clock signal; a booster which boosts a supply voltage by using the clock signal to output the boosted voltage; a potential detector which detects an output potential of the booster to output a frequency changing signal depending on the output potential; and a frequency changer which is interposed between the clock generator and the booster to change the frequency of the clock signal from the clock generator to the booster on the basis of the frequency changing signal.

A radio frequency front end for a television band receiver and spectrum sensor includes a first plurality of adaptive matching networks connected to a signal summer that combines signals received by the first plurality of antennas respectively connected to the first plurality of adaptive matching networks and outputs a combined signal to each of a second plurality of downconverter / tuners. The downconverter / tuners are respectively or collectively connected to an analog to digital converter that converts output of the second plurality of downconverter / tuners into at least one digital signal that is output to the television band receiver and spectrum sensor.

The present invention discloses an architecture for a concurrent dual-band high-frequency receiver. The invention combines a concurrent dual-band front-end subsystem having a dual-band antenna, dual-band pre-amplifier filter and concurrent dual-band LNA with a novel image rejection downconverter to provide the functions of a typical receiver, including reception, amplification and downconversion of a signal in two discrete desired frequency bands simultaneously.

A simultaneous multiple channel receiver (“SMCR”) for receiving a combined signal having a plurality of carrier signals, where each carrier signal in the plurality of carriers signals corresponds to a frequency channel, and in response, simultaneously producing a plurality of output data stream signals, is disclosed. The SMCR may include a down-converter front-end capable of receiving the combined signal, a plurality of digital signal processors, wherein each digital signal processor of the plurality of digital signal processors is capable of producing an output data stream signal of the plurality of output data stream signals, and a multi-band filter in signal communication with both the down-converter front-end and the plurality of digital signal processors.

In a lighting arrangement comprising a LED array and a DC-DC-converter for supplying the LED array, the DC-DC-converter is an up-converter and the LED array is coupled between an input terminal and an output terminal. The up-converter generates a very low voltage over the LED array without making use of a transformer.