63 results about "Class e amplifier" patented technology

An inductive power transfer system comprises a transmitter coil TX and a receiver coil RX spaced from the transmitter coil. A transmitter circuit comprises the transmitter coil and is in the form of a Class E amplifier with a first inductor U_choke and a transistor in series between the terminals of a power supply, a first transmitter capacitor C_par in parallel with the transistor between the first inductor and a power supply terminal, a primary tank circuit in parallel with the first transmitter capacitor, the primary tank circuit comprising the transmitter coil and a second transmitter capacitor C_res arranged in parallel with the transmitter coil, and a third transmitter capacitor C_ser in series with the first inductor between the first transmitter capacitor and the primary tank circuit. The transistor is arranged to switch at a first frequency ω_d and the capacitance of the second transmitter capacitor is selected such that the resonant frequency ω_OTX of the primary tank circuit is greater than the first frequency. The receiver circuit comprises a Class E rectifier having a first receiver capacitor C_L arranged in parallel with a load R_L and a secondary tank circuit in parallel with the first receiver capacitor. The secondary tank circuit comprises the receiver coil and a second receiver capacitor C_res arranged in parallel or series with the receiver coil. A first diode D_r2 is provided between the secondary tank circuit and the first receiver capacitor. The capacitance of the second receiver capacitor is selected such that the resonant frequency ω_oRX of the secondary tank circuit differs from the first frequency, so that the secondary tank circuit operates in semi-resonance and maintains some reactive impedance. The transmitter circuit is configured to vary the first frequency, in order to achieve a desired impedance of the primary tank circuit.

An inductive power transfer system (10) for roadways includes at least one drive unit arrangement (50) coupled to at least one drive coil arrangement (40) disposed along a roadway (20) for generating a magnetic field extending upwardly from the roadway (20), and at least one vehicle (30) including a corresponding pickup coil arrangement (60) coupled to a power conditioning circuit arrangement (80, 200) for receiving the extending magnetic field for providing power to operate the at least one vehicle (30). The at least one drive unit arrangement (50) is operable to excite, for example at resonance, the at least one drive coil arrangement (40) at a fundamental frequency (f₀) of at least 30 kHz, preferably at least 50 kHz, more preferably at least 100 kHz, and most preferably at least 140 kHz. The at least one drive coil arrangement (40) is implemented to be substantially devoid of ferromagnetic components for providing a path for the extending magnetic field. Optionally, the at least one drive unit arrangement (50) is operable to employ a balanced class-E amplifier arrangement for exciting the at least one drive coil arrangement (40) at the fundamental frequency (f₀). Optionally, the at least one drive unit arrangement (50) is operable to employ one or more Silicon Carbide semiconductor devices for switching the currents provided to the corresponding at least one drive coil arrangement (40). Optionally, there is further included a passive and/or active suppression arrangement (100, 110, 120, 130, 140) for suppressing harmonic magnetic field components generated by the system (10) at multiples of the fundamental frequency (f₀) when in operation.

A wireless power transmission system transmits power wirelessly from a power transmitter to a power receiver. The power transmitter includes a class E amplifier, a transmitting-end resonant circuit, a detector that detects a voltage or current waveform at a predetermined position in the class E amplifier in accordance with the impedance of the transmitting-end resonant circuit as viewed from the class E amplifier, and a signal extractor that extracts a signal according to the waveform. The power receiver includes a receiving-end resonant circuit, a rectifier circuit, a power reproducing section, and an impedance changer connected between the rectifier circuit and the power reproducing section to change its impedance. When the impedance is changed, the detector detects the waveform variation and the signal extractor extracts and outputs a signal corresponding to the waveform detected by the detector.

The invention discloses an electric field coupling-based wireless power transmission system. The system comprises a power supply circuit, a high-frequency inverter circuit, a tuning circuit, an electric field coupling polar plate, a rectifier filter circuit and a load circuit and is characterized by also comprising a coupling capacitance detection module, a controller and a fixed frequency drive circuit; a capacitance compensation array is arranged in the tuning circuit; the controller detects parameters of the electric field coupling polar plate and controls compensation values of the capacitance compensation array through the coupling capacitance detection module, and outputs fixed frequency control signals; and the fixed frequency signals are transmitted to the fixed frequency drive circuit, and then the high-frequency inverter circuit is driven to work. The electric field coupling-based wireless power transmission system has the advantages that based on the electric field coupling, the transmission capacity and efficiency of the system are improved by adopting an E amplifier; and by arranging the coupling capacitance detection module, the electric field coupling polar plate of the system is detected in real time, and the capacitance compensation value can be effectively controlled, so that the system is kept in the soft switching state, and the power transmission stability and reliability of the system are improved.

A power supply including an inverter receiving a DC input signal from a DC input source (11). The inverter is implemented as a single-ended inverter. Each inverter is driven by a signal source (13A, 13B), which outputs an AC signal. The output from each inverter is input to a first stage harmonic filter. The power supply includes an output circuit that includes a rectifier (D1) arranged about a point so that if the inverter attempts to drive the point beyond a predetermined voltage, the rectifier conducts in order to return at least one of power and current to the DC input source. The output from the first harmonic filter (L1A, C1; L1B, C1) is output to a second harmonic filter (L2, C2) and is then output from the power supply.

A power converter device and method are provided. The power converter device includes an input power source and an input inductor configured for coupling a power of the input power source to the device. A switch is configured to regulate a power of the input power source through the input inductor. A shunting diode is coupled between the switch and the input inductor. A resonant load is coupled with the input inductor. A switching element is coupled with the input inductor and the resonant load and configured to operate at a fixed frequency. The power converter device also includes a control circuit for modulating a frequency of the switch and a driving module for driving the switching element at the fixed frequency. In an exemplary embodiment, the power converter device is a Class-E amplifier. The fixed frequency is a frequency equal to a resonant frequency of the resonant load. In one embodiment, the power converter device is configured as an integrated circuit device.

A power supply including an inverter receiving a DC input signal from a DC input source (11). The inverter is comprised of two half bridges (S1 A, S2A and S1B, S2B). Each inverter is driven by a signal source (13A, 13B), which outputs an AC signal. The output from each inverter is input to a first stage harmonic filter. The power supply includes an output circuit that includes first and second rectifiers (D1, D2) arranged about a point so that if the inverter attempts to drive the point beyond a predetermined first and second voltage, the respective rectifier conducts in order to return at least one of power and current to the DC input source. The output from the first harmonic filter (L1A, C1; L1B, C1) is output to a second harmonic filter (L2, C2) and is then output from the power supply.

Systems, methods and apparatus are disclosed for amplifiers for wireless power transfer. In one aspect a method is provided for controlling operation of an amplifier, such as a class E amplifier. The method may include monitoring an output of the amplifier. The method may further include adjusting a timing of an enabling switch of the amplifier based on the output of the amplifier.

A Class-E amplifier has bee adapted for use in the radio frequency section of a magnetic resonance imaging (MRI) system. A drive signal is produces by modulating the envelope of a radio frequency carrier signal and then applied to a switch in the Class-E amplifier. The switch is connected in series with a choke between a supply voltage terminal and circuit ground with an output node formed between the choke and the switch. The output node is coupled to circuit ground by a shunt capacitor. In a preferred embodiment, a pair of such amplifiers, that are Π radians out of phase, are connected to each rung of a transverse electromagnetic transmit array type radio frequency coil of the MRI system.

A Class-E amplifier has been adapted for use in the radio frequency section that drives a transmit coil of a magnetic resonance imaging (MRI) system. The Class-E amplifier responds to a radio frequency carrier signal and a control signal by producing a radio frequency excitation signal for driving the transmit coil. The Class-E amplifier includes a pickup coil that senses a signal emitted from the transmit coil and produces a feedback signal that is used to alter the control signal and thereby control production of the radio frequency excitation signal.

An amplifier comprises a power source, a load network comprising a load and a resonance circuit, an input branch having a first end electrically coupled to the power source and a second end electrically coupled to the load network, and an active switch having one terminal electrically coupled to the second end of the input branch. The input branch including at least one parallel-LC-circuit configured to provide an infinitely large impedance at harmonics of a determined order.

The invention relates to a wireless energy supply and wireless acquisition system of a nerve tract implanted electrode based on a vlsivery large scale integrated circuit (VLSI), comprising an internalimplanted circuit device and an external circuit device, wherein the internal implanted circuit device comprises a nerve tract complex potential acquisition circuit, an encode circuit and a 2ASK modulation circuit of a 2ASK modulation device, a rectifying circuit and a voltage stabilizing circuit of a wireless energy transmission receiving circuit, and an internal coupling coil, and the wirelessenergy transmission receiving circuit is manufactured by a VLSI technology; and the external circuit device comprises a 2ASK demodulation circuit, a radio-frequency oscillator and a class-E amplifierof a wireless energy transmission emitting circuit, a circuit board assembled by separate elements and an external coupling coil. The wireless energy supply and wireless acquisition system not only realizes the wireless energy supply of the internal implanted circuit device, but also realizes the wireless transmission of the nerve tract implanted electrode recorded on nerve tract complex potential, and can be used for detecting a peripheral nerve system when an animal does somatic movement in a waking state; and in addition, the power consumption of the wireless energy supply and wireless acquisition system is reduced by manufacturing a wireless energy supply chip and a wireless acquisition system by the VLSI technology.

A quadra-polar modulator that is simple to implement and also provides good noise performance. The quadra-polar modulator includes four amplitude modulators and a combiner. Each amplitude modulator modulates a respective carrier signal with a respective input signal to provide a respective output signal. The combiner then combines the four output signals from the four amplitude modulators to provide a modulated signal. Each amplitude modulator may be implemented with a switching amplifier, such as a supply modulated class E amplifier. Two input signals are obtained by summing separately an inphase (I) modulating signal and an inverted I modulating signal with an offset value. The other two input signals are obtained by summing separately a quadrature (Q) modulating signal and an inverted Q modulating signal with the offset value. The offset value can be selected based on the expected magnitude of the modulating signals. The four carrier signals are in quadrature to each other.

A medical apparatus includes an extracorporeal power source that transmits electrical power via a radio frequency signal to a medical device implanted inside an animal. The extracorporeal power source has a Class-E amplifier with a choke and a semiconductor switch connected in series between a source of a supply voltage and circuit ground. An output node of the amplifier is formed between choke and the switch and connected to a transmitter antenna. A shunt capacitor couples the amplifier's output node to the circuit ground. Controlled operation of the switch produces bursts of the radio frequency signal that are pulse width modulated to control the amount of energy being sent to the implanted medical device.

The invention relates to an inductive power transfer transmitter comprising class-E amplifier driver arranged to drive a primary tank circuit including a transmitter coil, in which the driver frequency is tuned to drive the primary tank circuit when the primary tank circuit is in an unloaded condition.

The invention discloses a solar plexus electrical stimulation system used for treating type 2 diabetes mellitus. The system comprises an in-vitro program control instrument, an individual controller, an in-vivo stimulator implanted under the skin of the lateral abdomen of a patient to emit an electric pulse, and an electrode implanted into the solar plexus of the patient, wherein the in-vitro program control instrument is connected with the individual controller through a data cable; the individual controller is connected with the in-vivo stimulator in a radio-frequency communication manner; the in-vivo stimulator is connected with the electrode through a conducting wire; the in-vitro program control instrument is a computer equipped with operation software of the solar plexus electrical stimulation system; the individual controller integrates a functional module E type amplifier; the in-vivo stimulator comprises four functional units, namely a radio-frequency receiver, a micro processor, a double-channel pulse generator and a power supply system; the electrode is a bipolar electrode. The invention discovers that the solar plexus block can be used for the treatment of the type 2 diabetes mellitus; the solar plexus electrical stimulation system is simple, convenient and flexible in operation, can be used for effectively treating diabetes with few complications.

A class E amplifier circuit comprises a first class E amplifier connected to receive a first signal and operable to amplify the first signal and to output such an amplified first signal and a second class E amplifier connected to receive a second signal related to the first signal, and operable to amplify the second signal and to output such an amplified second signal. The circuit also comprises a combiner having first and second inputs connected to receive amplified signals from the first and second class E amplifiers respectively, and phase shift means operable to introduce a phase shift between signals for combination at the combiner.

The invention relates to an implementation method of a high-efficiency Doherty power amplifier based on a switching resonant structure. The switching resonant structure for inhibiting the higher harmonic component of an auxiliary power amplifier is arranged behind the auxiliary power amplifier so that the auxiliary power amplifier realizes class E work; the switching resonant structure comprises a switch, and a resistor, a capacitor and an inductor, the three of which are connected with the switch; an inductance value is optimized to enable a signal to resonate under a fundamental frequency, and therefore, a high impedance characteristic is presented to harmonics and an orthogonal relation between the time domain voltage and the current waveform of an ideal class E amplifier is realized. As a result, the efficiency of the Doherty power amplifier is greatly improved under a high linearity condition. The inductance value of the novel switching resonant structure decides the working frequency thereof; the inductance value in the switching resonant structure is reasonably calculated, and meanwhile, the implementation of a zero-current switch of the class E power amplifier is considered to guarantee the implementation of high efficiency performance of the power amplifier within a working frequency range.

A two-stage amplifier is provided, which in the first stage, a first amplifier generates a non-linear square wave based on a harmonic input. The non-linear square wave has the same frequency as the harmonic input and is provided as an input to the second stage, in which a second amplifier generates an amplified harmonic output. The first amplifier and/or second amplifier can comprise a group-III nitride-based Heterostructure Field Effect Transistor (HFET). Additionally, the first amplifier can comprise a multi-harmonic Class F amplifier and the second amplifier can comprise a Class E amplifier.