Abstract: Various embodiments of the present disclosure are directed towards a method for forming a varactor comprising a reduced surface field (RESURF) region. The method includes forming a drift region having a first doping type within a substrate. A RESURF region having a second doping type is formed within the substrate such that the RESURF region is below the drift region. A gate structure is formed on the substrate. A pair of contact regions is formed within the substrate on opposing sides of the gate structure. The contact regions respectively abut the drift region and have the first doping type, and wherein the first doping type is opposite the second doping type.

Abstract: In a file sharing system, a key manager unit realizes a correspondence between the first user identifier and the first public key in response to a registration request of the first user, generates a first key material for encrypting the first file into a first encrypted file, and generates a first credential according to the first user identifier, the first file identifier, the first public key and the first key material after receiving an access-right claim request to the first file from the first user. A file storage unit stores the first encrypted file and the first credential. The first user uses the first user identifier, the first file identifier and the first private key to retrieve the first key material out of the first credential, and uses the first key material to decrypt the first encrypted file into the first file.

Abstract: The invention provides electronic apparatus includes an antenna, a switch, a power generator, a battery, and a controller. The antenna receives a wireless signal. The switch transports the wireless signal to a first terminal or a second terminal according to a mode selecting signal. The power generator is coupled to the second terminal for receiving the wireless signal. The power generator generates a charging power according to the wireless signal. The charging power is provided to charge the battery. The controller generates the mode selecting signal by detecting the electronic apparatus is in a non-operation mode or not.

Abstract: Method for performing dynamic impedance matching and communication apparatus thereof are provided. With respect to an operating band of an impedance matching circuit of a communication device, a first number of times of tuning are performed on a first element of an impedance matching circuit, and a second number of times of tuning are performed on a second element of the impedance matching circuit, wherein the first number is different from the second number.

Abstract: A communication system includes a first antenna, a second antenna, a first transceiver, a second transceiver, and a phase and power distribution transform circuit. The phase and power distribution transform circuit is coupled between the first antenna, the second antenna, the first transceiver, and the second transceiver. The phase and power distribution transform circuit is configured to adjust the phase and power of each signal from the first antenna, the second antenna, the first transceiver, and/or the second transceiver, thereby improving the communication quality of the communication system.

Abstract: A communication system includes a first antenna, a second antenna, a first transceiver, a second transceiver, and a phase and power distribution transform circuit. The phase and power distribution transform circuit is coupled between the first antenna, the second antenna, the first transceiver, and the second transceiver. The phase and power distribution transform circuit is configured to adjust the phase and power of each signal from the first antenna, the second antenna, the first transceiver, and/or the second transceiver, thereby improving the communication quality of the communication system.

Abstract: Method for performing dynamic impedance matching and communication apparatus thereof are provided. With respect to an operating band of an impedance matching circuit of a communication device, a first number of times of tuning are performed on a first element of an impedance matching circuit, and a second number of times of tuning are performed on a second element of the impedance matching circuit, wherein the first number is different from the second number.

Abstract: A mobile communication device and an impedance matching method thereof are provided. The mobile communication device includes an antenna, a power amplifier, a tunable matching circuit, a power detection circuit and a controller. The tunable matching circuit determines an output impedance encountered by a radio frequency (RF) signal transmitted by the power amplifier to the antenna when the RF signal enters the tunable matching circuit. The power detection circuit detects a forward power of the RF signal entering the antenna and a reflected power of the antenna. The controller tunes the tunable matching circuit according to a frequency range currently used by the mobile communication device, the forward power and the reflected power to steer the output impedance toward a corresponding load-pull impedance that the power amplifier has in the frequency range.

Abstract: Method for performing dynamic impedance matching and communication apparatus thereof are provided. With respect to an operating band of an impedance matching circuit of a communication device, a first number of times of tuning are performed on a first element of an impedance matching circuit, and a second number of times of tuning are performed on a second element of the impedance matching circuit, wherein the first number is different from the second number.

Abstract: The invention provides electronic apparatus includes an antenna, a switch, a power generator, a battery, and a controller. The antenna receives a wireless signal. The switch transports the wireless signal to a first terminal or a second terminal according to a mode selecting signal. The power generator is coupled to the second terminal for receiving the wireless signal. The power generator generates a charging power according to the wireless signal. The charging power is provided to charge the battery. The controller generates the mode selecting signal by detecting the electronic apparatus is in a non-operation mode or not.

Abstract: A radio-frequency (RF) processing device, for a wireless communication device, is disclosed. The RF processing device comprises an antenna, an RF-signal processing module, a controller, for generating a control signal according to a band switching signal, and a matching adjustment module for adjusting an impedance between the antenna and the RF-signal processing module according to the control signal.

Abstract: A mobile communication device and an impedance matching method thereof are provided. The mobile communication device includes an antenna, a power amplifier, a tunable matching circuit, a power detection circuit and a controller. The tunable matching circuit determines an output impedance encountered by a radio frequency (RF) signal transmitted by the power amplifier to the antenna when the RF signal enters the tunable matching circuit. The power detection circuit detects a forward power of the RF signal entering the antenna and a reflected power of the antenna. The controller tunes the tunable matching circuit according to a frequency range currently used by the mobile communication device, the forward power and the reflected power to steer the output impedance toward a corresponding load-pull impedance that the power amplifier has in the frequency range.

Abstract: Method for performing dynamic impedance matching and communication apparatus thereof are provided. With respect to an operating band of an impedance matching circuit of a communication device, a first number of times of tuning are performed on a first element of an impedance matching circuit, and a second number of times of tuning are performed on a second element of the impedance matching circuit, wherein the first number is different from the second number.

Abstract: A radio-frequency (RF) processing device, for a wireless communication device, is disclosed. The RF processing device comprises an antenna, an RF-signal processing module, a controller, for generating a control signal according to a band switching signal, and a matching adjustment module for adjusting an impedance between the antenna and the RF-signal processing module according to the control signal.

Abstract: A wireless communication module is proposed, in which an LTCC substrate is employed. The LTCC substrate comprises at least a first layer and a second layer. At least first and second communication elements are deposited on the first layer, and a matching network is embedded in the second layer. The matching network couple the first and second communication elements to provide matched impedance, such that radio frequency signals are transmitted without distortion. Specifically, the first layer is the surface of the LTCC substrate, whereas the second layer is a depth inside the LTCC substrate. The matching network comprises at least one inductance or capacitance buried in the second layer.

Abstract: A frequency synthesizer for dual-band high frequency RF application. The frequency synthesizer first uses a frequency-locked loop circuit (“FLL”) to achieve self-calibration and frequency-locking, and then uses a phase-locked loop circuit (“PLL”) to achieve phase-locking. During the FLL, the PLL is de-activated by control signals from the digital control and state machine of the FLL. The varactor of the VCO is initially connected to a fixed voltage, thus isolating the varactor from the PLL. The FLL adjusts the VCO's capacitor array by varying the five binary control bits from the state machine and digital control, until frequency-locking and self-calibration is achieved. Then, those five binary weighting control bits are also fixed for the VCO. The PLL is then activated to perform a fine-tuning and phase-locking loop, where the varactor of the VCO is controlled by the signal from the charge pump and the low-pass filter.

Abstract: A frequency synthesizer for dual-band high frequency RF application. The frequency synthesizer first uses a frequency-locked loop circuit (“FLL”) to achieve self-calibration and frequency-locking, and then uses a phase-locked loop circuit (“PLL”) to achieve phase-locking. During the FLL, the PLL is de-activated by control signals from the digital control and state machine of the FLL. The varactor of the VCO is initially connected to a fixed voltage, thus isolating the varactor from the PLL. The FLL adjusts the VCO's capacitor array by varying the five binary control bits from the state machine and digital control, until frequency-locking and self-calibration is achieved. Then, those five binary weighting control bits are also fixed for the VCO. The PLL is then activated to perform a fine-tuning and phase-locking loop, where the varactor of the VCO is controlled by the signal from the charge pump and the low-pass filter.