Abstract: A radio frequency (RF) transmitter includes an analog RF power amplifier and a digital Dynamic Error Vector Magnitude (DEVM) correction module. The DEVM correction module compensates for time-dependent variations in an instantaneous gain of the RF power amplifier. The time-dependent variations may be variations that occur during a period the RF power amplifier is turned on. The RF transmitter may further include one or more analog baseband circuits, and one or more respective baseband digital pre-distortion (DPD) modules that compensate for amplitude modulation to amplitude modulation (AM2AM) nonlinearities in the analog baseband circuits. The digital DEVM correction module and baseband DPD modules may each include respective look-up tables having values determined by respective calibration operations.

Abstract: A notch filter is coupled to a first input node and a second input node, and is configured to present a capacitive load to a differential signal provided to the first and second input nodes, and to present a series-resonant inductive-capacitive load to a common-mode signal provided to the first and second input nodes. The notch filter includes a transformer and a capacitor bank. The transformer includes a first winding having a positive-polarity terminal coupled to the first input node and a second winding having a positive-polarity terminal coupled to the second input node. The capacitor bank includes a first capacitor coupled between a negative-polarity terminal of the first winding and a bias node, and a second capacitor coupled between a negative-polarity terminal of the second winding and the bias node. The first and second capacitors may be variable capacitors.

Abstract: A notch filter is coupled to a first input node and a second input node, and is configured to present a capacitive load to a differential signal provided to the first and second input nodes, and to present a series-resonant inductive-capacitive load to a common-mode signal provided to the first and second input nodes. The notch filter includes a transformer and a capacitor bank. The transformer includes a first winding having a positive-polarity terminal coupled to the first input node and a second winding having a positive-polarity terminal coupled to the second input node. The capacitor bank includes a first capacitor coupled between a negative-polarity terminal of the first winding and a bias node, and a second capacitor coupled between a negative-polarity terminal of the second winding and the bias node. The first and second capacitors may be variable capacitors.

Abstract: A method for calibrating a radio frequency (RF) transmitter to compensate for a frequency-dependent in-phase quadrature (FDIQ) mismatch is disclosed. The method may include determining in-phase quadrature (IQ) amplitude and phase mismatches of the RF transmitter for a lower side band (LSB) and an upper side band (USB), determining a FDIQ mismatch based on linear fitting the IQ amplitude and phase mismatches for the LSB and the USB, modifying the FDIQ mismatch based on flipping a FDIQ phase mismatch in the LSB and flipping a FDIQ phase mismatch in the USB to generate a modified FDIQ mismatch, determining Fourier coefficients based on applying an inverse fast Fourier transform to the modified FDIQ mismatch, and determining FIR coefficients for a finite impulse response (FIR) filter of the RF transmitter based on windowing the Fourier coefficients.

Abstract: A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Abstract: A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Abstract: A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Abstract: A notch filter is coupled to a first input node and a second input node, and is configured to present a capacitive load to a differential signal provided to the first and second input nodes, and to present a series-resonant inductive-capacitive load to a common-mode signal provided to the first and second input nodes. The notch filter includes a transformer and a capacitor bank. The transformer includes a first winding having a positive-polarity terminal coupled to the first input node and a second winding having a positive-polarity terminal coupled to the second input node. The capacitor bank includes a first capacitor coupled between a negative-polarity terminal of the first winding and a bias node, and a second capacitor coupled between a negative-polarity terminal of the second winding and the bias node. The first and second capacitors may be variable capacitors.

Abstract: A radio frequency (RF) transmitter includes an analog RF power amplifier and a digital Dynamic Error Vector Magnitude (DEVM) correction module. The DEVM correction module compensates for time-dependent variations in an instantaneous gain of the RF power amplifier. The time-dependent variations may be variations that occur during a period the RF power amplifier is turned on. The RF transmitter may further include one or more analog baseband circuits, and one or more respective baseband digital pre-distortion (DPD) modules that compensate for amplitude modulation to amplitude modulation (AM2AM) nonlinearities in the analog baseband circuits. The digital DEVM correction module and baseband DPD modules may each include respective look-up tables having values determined by respective calibration operations.

Abstract: A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Abstract: A method of operating a near-field communication (NFC) circuit, the method including: receiving an interference signal and a data signal through an antenna; adjusting magnitudes of the received interference signal and the received data signal; down-converting frequencies of the interference signal and the data signal, the magnitudes of which are adjusted; filtering the data signal by removing the frequency down-converted interference signal; and adjusting a magnitude of the filtered data signal. The adjusting of the magnitudes of the received interference signal and the received data signal may include adjusting the magnitudes of the interference signal and the data signal such that linearity of the data signal is maintained during signal processing performed on the interference signal and the data signal in the down-converting of the frequencies of the interference signal and the data signal, the filtering of the data signal, and the adjusting of the magnitude of the filtered data signal.

Abstract: A near field communications (NFC) device includes a receiving module and a transmitting module. The receiving module includes a receiver receiving an analog signal that includes a carrier signal and data, an analog-to-digital converter converting the analog signal to a digital signal, and a filter filtering the digital signal. The transmitting module includes a direct current-direct current (DC-DC) converter having an operating frequency belonging to a stop band of the filter, and a transmitter receiving power from the DC-DC converter and receiving a system clock signal.

Abstract: A near field communications (NFC) device includes a receiving module and a transmitting module. The receiving module includes a receiver receiving an analog signal that includes a carrier signal and data, an analog-to-digital converter converting the analog signal to a digital signal, and a filter filtering the digital signal. The transmitting module includes a direct current-direct current (DC-DC) converter having an operating frequency belonging to a stop band of the filter, and a transmitter receiving power from the DC-DC converter and receiving a system clock signal.

Abstract: Operating an NFC device to communicate with an NFC tag may include converting the NFC device between operating in a standby mode or an active mode, based on whether communication between the NFC device and an NFC tag is failed while the NFC device is operating in an active mode, detecting an NFC tag based on a tag detection sensitivity associated with the NFC device operating in the standby mode, converting the NFC device to operating in the active mode when an NFC tag is detected in the standby mode and adaptively controlling the tag detection sensitivity based on one or more user environment parameters associated with the NFC device. Power consumption and the tag detection sensitivity may be optimized based on adaptively controlling the tag detection sensitivity based on the one or more user environment parameters.

Abstract: A method of operating a near-field communication (NFC) circuit, the method including: receiving an interference signal and a data signal through an antenna; adjusting magnitudes of the received interference signal and the received data signal; down-converting frequencies of the interference signal and the data signal, the magnitudes of which are adjusted; filtering the data signal by removing the frequency down-converted interference signal; and adjusting a magnitude of the filtered data signal. The adjusting of the magnitudes of the received interference signal and the received data signal may include adjusting the magnitudes of the interference signal and the data signal such that linearity of the data signal is maintained during signal processing performed on the interference signal and the data signal in the down-converting of the frequencies of the interference signal and the data signal, the filtering of the data signal, and the adjusting of the magnitude of the filtered data signal.

Abstract: Operating an NFC device to communicate with an NFC tag may include converting the NFC device between operating in a standby mode or an active mode, based on whether communication between the NFC device and an NFC tag is failed while the NFC device is operating in an active mode, detecting an NFC tag based on a tag detection sensitivity associated with the NFC device operating in the standby mode, converting the NFC device to operating in the active mode when an NFC tag is detected in the standby mode and adaptively controlling the tag detection sensitivity based on one or more user environment parameters associated with the NFC device. Power consumption and the tag detection sensitivity may be optimized based on adaptively controlling the tag detection sensitivity based on the one or more user environment parameters.

Abstract: Disclosed are a temperature compensation apparatus and method. The apparatus includes a reference signal generator that supplies at least one of a first current which is constant regardless of temperature variation and a second current which is proportional to temperature variation, a slope amplifier that determines a first output current having a second temperature coefficient which is a multiple of a first temperature coefficient of the second current, based on the first current and the second current, and a slope controller that determines a second output current having a third temperature coefficient, using a weighted average of the first current and the second current.

Abstract: Provided is a Radio Frequency (RF) communication apparatus and a method for detecting power. The RF communication apparatus includes a receiver that receives a segment value indicating one of multiple transmission output power ranges, a power detector that detects a strength of an RF transmission signal in an output power range corresponding to the segment value, and a transmitter that transmits the strength of the detected RF transmission signal. The power detector includes a feedback unit that receives the fed-back RF transmission signal, an RF core unit that generates a Root Mean Square (RMS) of the RF transmission signal, and a converter that converts a current signal corresponding to the RMS of the RF transmission signal into a voltage signal, and converts the converted voltage signal from a differential signal to a single signal.

Abstract: An electronic device for and method of determining a calibration code is provided. The electronic device includes a modem configured to receive a transmission signal, determine a calibration code that minimizes distortion of the transmission signal, and calibrate the distortion of the transmission signal using the calibration code.

Abstract: Provided is a Radio Frequency (RF) communication apparatus and a method for detecting power. The RF communication apparatus includes a receiver that receives a segment value indicating one of multiple transmission output power ranges, a power detector that detects a strength of an RF transmission signal in an output power range corresponding to the segment value, and a transmitter that transmits the strength of the detected RF transmission signal. The power detector includes a feedback unit that receives the fed-back RF transmission signal, an RF core unit that generates a Root Mean Square (RMS) of the RF transmission signal, and a converter that converts a current signal corresponding to the RMS of the RF transmission signal into a voltage signal, and converts the converted voltage signal from a differential signal to a single signal.