Abstract: A detection device is provided. The detection device includes a transmitter and a detector. The transmitter supplies an induced current to an antenna and to adjust a strength of an induced voltage generated in the antenna by adjusting the induced current. The detector monitors the strength of the induced voltage of the antenna and generates a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

Abstract: A detection device is provided. The detection device includes a transmitter and a detector. The transmitter supplies an induced current to an antenna and to adjust a strength of an induced voltage generated in the antenna by adjusting the induced current. The detector monitors the strength of the induced voltage of the antenna and generates a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

Abstract: A detection device is provided. The detection device includes a transmitter and a detector. The transmitter supplies an induced current to an antenna and to adjust a strength of an induced voltage generated in the antenna by adjusting the induced current. The detector monitors the strength of the induced voltage of the antenna and generates a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

Abstract: A near field communication (NFC) device includes a resonance unit and an NFC chip. The resonance unit emits an electromagnetic wave to communicate data with an external NFC card in a reader mode. The NFC chip estimates a distance between the resonance unit and the external NFC card based on an antenna voltage generated by the resonance unit while the resonance unit emits the electromagnetic wave, and adjusts a magnitude of the electromagnetic wave based on the estimated distance.

Abstract: A transmitter of a NFC device includes a current detector which detects a first current flowing in an output node of a regulator and outputs a current detection signal related to a result of the detection, and a control block which compares the current detection signal with a reference current and generates a control signal for controlling a voltage of the output node according to a result of the comparison.

Abstract: The near field communication (NFC) circuit includes an NFC reader circuit configured to communicate with an outside through an antenna, a resonant and matching circuit connected between the NFC reader circuit and the antenna, an NFC card circuit connected to nodes and configured to communicate with the outside through the antenna, and a processor configured to output a plurality of control signals when the NFC reader circuit is enabled, wherein the NFC card circuit is configured to control a resonant frequency of the antenna in response to the plurality of control signals.

Abstract: A radio frequency (RF) transmission circuit includes an antenna connection terminal, a plurality of amplifiers connected to the antenna connection terminal in parallel, a plurality of drivers for driving the plurality of amplifiers, and a control circuit configured to control operation of the plurality of drivers based on information indicating a characteristic of a RF signal to be transmitted through the antenna connection terminal.

Abstract: A detection device is provided. The detection device includes a transmitter and a detector. The transmitter supplies an induced current to an antenna and to adjust a strength of an induced voltage generated in the antenna by adjusting the induced current. The detector monitors the strength of the induced voltage of the antenna and generates a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

Abstract: A wireless communication device includes an antenna, a transceiver, a filter circuit and an attenuation circuit. The transceiver includes a transmission electrode and a receive electrode, and communicates with an external device through the antenna. The filter circuit is coupled between the transmission electrode and the antenna, and includes a harmonic trap circuit that eliminates a harmonic element of a carrier frequency of an outgoing signal provided from the transceiver through the transmission electrode. The attenuation circuit is coupled between the receive electrode and the antenna, and provides an incoming signal received through the antenna to the receive electrode after reducing a voltage of the incoming signal.

Abstract: A transmitter of a NFC device includes a current detector which detects a first current flowing in an output node of a regulator and outputs a current detection signal related to a result of the detection, and a control block which compares the current detection signal with a reference current and generates a control signal for controlling a voltage of the output node according to a result of the comparison.

Abstract: A near field communication (NFC) device includes a resonance unit and an NFC chip. The resonance unit emits an electromagnetic wave to communicate data with an external NFC card in a reader mode. The NFC chip estimates a distance between the resonance unit and the external NFC card based on an antenna voltage generated by the resonance unit while the resonance unit emits the electromagnetic wave, and adjusts a magnitude of the electromagnetic wave based on the estimated distance.

Abstract: A radio frequency (RF) transmission circuit includes an antenna connection terminal, a plurality of amplifiers connected to the antenna connection terminal in parallel, a plurality of drivers for driving the plurality of amplifiers, and a control circuit configured to control operation of the plurality of drivers based on information indicating a characteristic of a RF signal to be transmitted through the antenna connection terminal.

Abstract: The near field communication (NFC) circuit includes an NFC reader circuit configured to communicate with an outside through an antenna, a resonant and matching circuit connected between the NFC reader circuit and the antenna, an NFC card circuit connected to nodes and configured to communicate with the outside through the antenna, and a processor configured to output a plurality of control signals when the NFC reader circuit is enabled, wherein the NFC card circuit is configured to control a resonant frequency of the antenna in response to the plurality of control signals.

Abstract: A wireless communication device includes an antenna, a transceiver, a filter circuit and an attenuation circuit. The transceiver includes a transmission electrode and a receive electrode, and communicates with an external device through the antenna. The filter circuit is coupled between the transmission electrode and the antenna, and includes a harmonic trap circuit that eliminates a harmonic element of a carrier frequency of an outgoing signal provided from the transceiver through the transmission electrode. The attenuation circuit is coupled between the receive electrode and the antenna, and provides an incoming signal received through the antenna to the receive electrode after reducing a voltage of the incoming signal.

Abstract: An auto gain controller is provided. The auto gain controller includes a variable gain amplification unit configured to receive differential input signals, adjust an amplification gain based on an auto gain control voltage and output differential output signals. The auto gain controller also includes a peak detector configured to detect at least one peak value among the amplified differential output signals, a comparator configured to compare the at least one detected peak value with a reference voltage and generate a comparison signal, and a voltage adjusting circuit configured to adjust the auto gain control voltage and the reference voltage based on the comparison signal.

Abstract: An oscillator tuning system and an oscillator tuning method are provided. The system includes a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination. The method includes determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and tuning a driving frequency of the RFID oscillator according to a result of the determination.

Abstract: An oscillator tuning system and an oscillator tuning method are provided. The system includes a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination. The method includes determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and tuning a driving frequency of the RFID oscillator according to a result of the determination.

Abstract: An auto gain controller is provided. The auto gain controller includes a variable gain amplification unit configured to receive differential input signals, adjust an amplification gain based on an auto gain control voltage and output differential output signals. The auto gain controller also includes a peak detector configured to detect at least one peak value among the amplified differential output signals, a comparator configured to compare the at least one detected peak value with a reference voltage and generate a comparison signal, and a voltage adjusting circuit configured to adjust the auto gain control voltage and the reference voltage based on the comparison signal.

Abstract: A limiter for controlling an overvoltage and an RFID tag having the same are provided. The limiter includes a first limiter part and a second limiter part serially connected to the first limiter part. The second limiter part has at least one limit diode whose threshold voltage is lower than that of elements in the first limiter part. Accordingly, if an overvoltage is input, the limiter can maximize the input current drop so that the limiter can maximize the leakage voltage. As a result, the RFID tag can prevent the RFID driving part from being damaged due to the overvoltage. In addition, the RFID tag can normally operate regardless of the intensity of the driving voltage input from the RFID reader, so that the yields of products can improve.

Abstract: An oscillator tuning system and an oscillator tuning method are provided. The system includes a determination unit which determines whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and a frequency tuner which tunes a driving frequency of the RFID oscillator according to a result of the determination. The method includes determining whether a power which is used in an RFID tag having an RFID oscillator is greater than a reference value; and tuning a driving frequency of the RFID oscillator according to a result of the determination.