Abstract:
Disclosed herein is a wireless power transmission/reception apparatus. The wireless power transmission/reception apparatus includes a wireless power transmission unit and a wireless power reception unit. The wireless power transmission unit receives power, generates a wireless power signal to be wirelessly transmitted, wirelessly transmits the generated wireless power signal in a magnetic resonance manner, receives a returned wireless power signal and detects the number of power consumption devices, and wirelessly transmits a wireless power signal using resonance frequency appropriate for the number of power consumption devices.
Abstract:
A wireless power transmission/reception apparatus includes a wireless power transmission unit. The transmission unit is configured to generate a wireless power signal to be transmitted, transmit the wireless power signal using magnetic resonance, receive a reflected wireless power signal from a wireless power reception unit, determine whether a load device is present, and transmit a further wireless power signal when it is determined that the load device is present in such a way that impedance and output power depending on variation in a distance to the load device are tracked, and wireless power is supplied to the load device in an optimized state. Accordingly, a separate transceiver module is not provided for the purpose of performing communication between a transmitting end and a receiving end, and a reception environment is automatically detected, thus enabling wireless power to be transmitted in an optimal wireless power transmission state.
Abstract:
Disclosed herein is a wireless power transmission/reception apparatus. The wireless power transmission/reception apparatus includes a wireless power transmission unit and a wireless power reception unit. The wireless power transmission unit receives power, generates a wireless power signal to be wirelessly transmitted, wirelessly transmits the generated wireless power signal in a magnetic resonance manner, receives a returned wireless power signal and detects the number of power consumption devices, and wirelessly transmits a wireless power signal using resonance frequency appropriate for the number of power consumption devices.
Abstract:
A power amplifier apparatus includes: an amplifier configured to amplify an input signal; a sensing circuit connected to the amplifier and configured to sense a bias of the amplifier; and a biasing circuit connected to the sensing circuit and configured to provide a biasing current to the amplifier, wherein the sensing circuit is configured to change the biasing current based on the bias of the amplifier.
Abstract:
A power amplifier may include a first amplifying circuit configured to amplify an input RF signal; a second amplifying circuit connected to the first amplifying circuit in parallel configured to amplify the input RF signal; and a controller connected to at least one of the first amplifying circuit and the second amplifying circuit and configured to output a control signal in order to control an on-off state of at least one of the first amplifying circuit and the second amplifying circuit. Such an approach provides high efficiency without adding significant complexity to the power amplifier.
Abstract:
A switching circuit may include: the switching circuit includes a switching circuit unit including a first transistor and a second transistor connected to each other in series, the second transistor receiving a first control signal through a control terminal thereof, and an inverter connected between a control terminal of the first transistor and a first terminal of the first transistor. The inverter receives a second control signal and maintains a gate-source voltage level of the first transistor to a threshold voltage level of the first transistor or less, and levels of the first and second control signals are logically complementary to each other.
Abstract:
A power amplifier may include a first amplifying unit receiving a first bias signal to amplify a power level of an input signal; an envelope detecting unit detecting an envelope of the input signal; a comparing circuit unit comparing a peak value of the detected envelope with a preset reference voltage; and a second amplifying unit amplifying the power level of the input signal according to a second bias signal set depending on a comparison result of the comparing circuit unit.
Abstract:
An apparatus that generates and limits a bias current of a power amplifier is provided. The apparatus includes a bias current circuit that generates a bias current to bias the power amplifier, and critically limit an increase in bias current, and a band gap reference circuit that provides a reference voltage or a reference current to the bias current circuit. The bias current circuit is configured to critically limit the increase in bias current, as a first bias transistor that generates the bias current is converted from a triode region to a saturation region, based on the reference voltage or the reference current.
Abstract:
A power amplifying apparatus may include a first amplifying unit receiving power and amplifying a high frequency signal, a second amplifying unit receiving the power and amplifying the high frequency signal from the first amplifying unit, and a control unit controlling an operation of the first amplifying unit or the second amplifying unit. The first amplifying unit and the control unit are disposed on a complementary metal oxide semiconductor (CMOS) substrate, and the second amplifying unit is disposed on a GaAs substrate.