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: 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 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 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 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: Disclosed herein are a wireless power transmission apparatus and a transmission method thereof. The wireless power transmission apparatus is configured to include a wireless power transmitter generating a wireless power signal to be wireless transmitted, wirelessly transmitting the generated wireless power signal by a magnetic resonance manner, receiving a reflection wireless power signal to determine whether or not a load apparatus is presented, and supplying power to the load apparatus; and a wireless power receiver connected to the load apparatus and receiving the transmitted wireless power signal by the magnetic resonance manner and supplying it to the connected load apparatus and reflecting the remaining wireless power signal to the wireless power transmitter, whereby a transmission apparatus can recognize a receiving environment and resonance characteristics are improved, without a separate communication device or a system.

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: Disclosed herein is a wireless charging system that includes a transmission device including a primary coil and a reception device including a secondary coil, wherein the transmission device determines the presence or absence of the reception device upon receiving the remaining amount of current supplied from the primary coil to the secondary coil, and controls a voltage input to the primary coil based on the determination results. The wireless charging system can generate a sensing signal for determining the presence and absence of the reception device by measuring the amount of current applied from the transmitter coil to the receiver coil through the detection unit. Thus, the receiver controller of the wireless charging system can accurately determine whether to transmit power by comparing the sensing signal provided from the detection unit with a reference signal, thus reducing power consumption.

Abstract: Provided are an apparatus and a method for transmitting wireless power. According to an embodiment of the present invention, a wireless power transmission apparatus includes: a switching block receiving distributed power signals and delivering the power signals as periodical preamble signals that make a detour around a power amplification and transmission block or delivering the power signals to the power amplification and transmission block; the power amplification and transmission block amplifying the power signals and transmitting the power signals to a coil array block; a sensing block detecting the preamble signals on the respective paths that are delivered to the coil array block, and sensing changes in the preamble signals according to whether wireless power receiving apparatuses appear; and a power distribution and control block controlling the switching block according to sensing results to transmit the power signals to the power amplification and transmission block.

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: Disclosed are a wireless power transmitter capable of transmitting power wirelessly according to an impedance of an output side and a wireless power transceiver. There are provided a wireless power transmitter and a wireless power transceiver including: a wireless power transmitting unit converting input power into a preset transmission power and transmitting the converted input power wirelessly; and a controlling unit controlling a transmission of the transmission power according to a level of output impedance of the transmission power output from the wireless power transmitting unit.

Abstract: Disclosed herein is a display system incorporating wired and wireless charging apparatuses, including: a switching processing unit supplying and processing a power of a power supply unit according to a mode selected through a switch; a wireless charging unit connected to the switching processing unit and including a pad for wireless charging; a wired charging unit connected to the switching processing unit and a terminal for wired charging; a display unit connected to the switching processing unit; and a control unit connected to the switching processing unit to control operations according to the mode.

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 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.

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: Disclosed herein is a charging apparatus using a pad type electrode contact point, the charging apparatus including: a charging plate having a plate shape; and an attaching plate installed on a portable terminal to provide the power to a charging circuit of the portable terminal.

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: 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 an apparatus for transmitting and receiving wireless energy using meta-material structures having a zero refractive index. The apparatus includes a wireless energy transmission unit and a wireless energy reception unit. When external power is applied thereto, the wireless energy transmission unit generates wireless energy to be wirelessly transmitted, and then wirelessly transmits wireless energy, which is normally propagated radially when the generated wireless energy is transmitted, using a magnetic resonance method while concentrating the wireless energy in one direction.