Abstract: According to one aspect of the present disclosure, there is provided a device that includes: a first quadrature modulator configured to receive an in-phase portion of a baseband signal and a quadrature portion of the baseband signal, and to produce a first portion of an output signal according to the in-phase and quadrature portions of the baseband signal; a second quadrature modulator configured to receive a first modified signal and a second modified signal, and to produce a second portion of the output signal according to the first and second modified signals; an output circuit configured to sum the first and second portions of the output signal, and to transmit the output signal to an antenna; and a mode selection circuit configured to turn on the first quadrature modulator, to receive a control signal, and to determine whether to turn on the second quadrature modulator according to the control signal.

Abstract: A circuit in a wireless communications terminal/device and a method is described for reducing an image distortion. By measuring three gain mismatches of I path and Q path of a transceiver, and estimating a value of an IQ mismatch coefficient based on the three gain mismatches; and applying a measurement adjustment to the I path or the Q path based on the value of the IQ mismatch coefficient, the image distortion is reduced.

Abstract: A circuit in a wireless communications terminal/device and a method is described for reducing an image distortion. By measuring three gain mismatches of I path and Q path of a transceiver, and estimating a value of an IQ mismatch coefficient based on the three gain mismatches; and applying a measurement adjustment to the I path or the Q path based on the value of the IQ mismatch coefficient, the image distortion is reduced.

Abstract: According to one aspect of the present disclosure, there is provided a device that includes: a first quadrature modulator configured to receive an in-phase portion of a baseband signal and a quadrature portion of the baseband signal, and to produce a first portion of an output signal according to the in-phase and quadrature portions of the baseband signal; a second quadrature modulator configured to receive a first modified signal and a second modified signal, and to produce a second portion of the output signal according to the first and second modified signals; an output circuit configured to sum the first and second portions of the output signal, and to transmit the output signal to an antenna; and a mode selection circuit configured to turn on the first quadrature modulator, to receive a control signal, and to determine whether to turn on the second quadrature modulator according to the control signal.

Abstract: A low noise amplifier comprising an adjustable gain and a variable impedance controller is provided. The low noise amplifier is configured to sink current and to adjust a shunt resistance substantially simultaneously.

Abstract: A circuit in a wireless communications terminal/device and a method is described for reducing an image distortion. By measuring three gain mismatches of I path and Q path of a transceiver, and estimating a value of an IQ mismatch coefficient based on the three gain mismatches; and applying a measurement adjustment to the I path or the Q path based on the value of the IQ mismatch coefficient, the image distortion is reduced.

Abstract: A system, computer readable medium, and method are provided for calibrating a wireless transmitter. A transceiver that includes a radio frequency transmitter, a measurement receiver, and a local oscillator unit may be calibrated by adjusting the duty cycle of the radio frequency signals generated by the local oscillator unit. The method for calibrating the wireless transmitter includes the steps of collecting measurement data corresponding to a number of pre-defined duty ratio correction factors, calculating estimated optimum duty ratio correction factors based on the measurement data, and determining a final optimum duty ratio correction factor from the estimated optimum duty ratio correction factors. The pre-defined duty ratio correction factors may be selected to simplify the calculations for choosing the final optimum duty ratio correction factor. The wireless transmitter can be calibrated by configuring the local oscillator unit based on the final optimum duty ratio correction factor.

Abstract: A system, computer readable medium, and method are provided for calibrating a wireless transmitter. A transceiver that includes a radio frequency transmitter, a measurement receiver, and a local oscillator unit may be calibrated by adjusting the duty cycle of the radio frequency signals generated by the local oscillator unit. The method for calibrating the wireless transmitter includes the steps of collecting measurement data corresponding to a number of pre-defined duty ratio correction factors, calculating estimated optimum duty ratio correction factors based on the measurement data, and determining a final optimum duty ratio correction factor from the estimated optimum duty ratio correction factors. The pre-defined duty ratio correction factors may be selected to simplify the calculations for choosing the final optimum duty ratio correction factor. The wireless transmitter can be calibrated by configuring the local oscillator unit based on the final optimum duty ratio correction factor.

Abstract: IP2 calibration efficiency can be improved by passing the calibration signal through the transceiver's duplexer instead of inserting the calibration signal directly onto transceivers receive circuit. Passing the calibration signal through the duplexer may reduce IP2 calibration periods for transceivers having less-permeable duplexers, or duplexers that provide better than average separation between the RX and TX circuits. IP2 calibration inefficiencies can also be reduced by using a binary-like search when computing the in-phase and quadrature-phase path correction coefficients of the IP2 correction code.

Abstract: A method and terminal device for reducing an image distortion are provided. The terminal device generates a radio frequency signal from a first path that includes first and second low pass filters of in-phase and quadrature phase paths, produces a decomposed signal having in-phase and quadrature phase components in digital form based on the radio frequency signal, and determines a phase mismatch between the in-phase and quadrature phase components. Then the terminal device generates a bandwidth adjustment value based on the determined phase mismatch, further generates, based on the bandwidth adjustment value, first and second bandwidth control signals; and adjusts a bandwidth of first and second low pass filters based on the first and second bandwidth control signals to reduce the phase mismatch.

Abstract: A low noise amplifier comprising an adjustable gain and a variable impedance controller is provided. The low noise amplifier is configured to sink current and to adjust a shunt resistance substantially simultaneously.

Abstract: An apparatus comprises: radio frequency (RF) transceiver circuitry for electrical coupling to an antenna and including: a local oscillator (LO) circuit configured to generate a LO signal, and a mixer circuit configured to mix a CW tone signal with the LO signal; a measurement receiver path configured to measure an antenna signal, wherein the antenna signal includes the CW tone signal mixed with the LO signal; and baseband processing circuitry electrically coupled to the measurement receiver path and configured to adjust a clock duty ratio of the LO signal to reduce one or more counter intermodulation (CIM) signals in the antenna signal.

Abstract: A mobile device comprising an antenna, a receiver coupled to the antenna, and a transmitter coupled to the antenna, wherein the receiver, the transmitter, or both comprise a low noise amplifier comprising an adjustable gain and a variable impedance controller, and wherein the low noise amplifier is configured to sink current and to adjust a shunt resistance substantially simultaneously. Included is a method comprising receiving an electrical signal, substantially simultaneously adjusting an input impedance and a gain factor, amplifying the electrical signal, thereby producing an amplified signal, and outputting the amplified signal.

Abstract: An apparatus comprises: radio frequency (RF) transceiver circuitry for electrical coupling to an antenna and including: a local oscillator (LO) circuit configured to generate a LO signal, and a mixer circuit configured to mix a CW tone signal with the LO signal; a measurement receiver path configured to measure an antenna signal, wherein the antenna signal includes the CW tone signal mixed with the LO signal; and baseband processing circuitry electrically coupled to the measurement receiver path and configured to adjust a clock duty ratio of the LO signal to reduce one or more counter intermodulation (CIM) signals in the antenna signal.

Abstract: An embodiment method includes measuring, by a calibration device, a first output voltage of a variable gain amplifier (VGA) when the VGA is set at a first gain setting and measuring, by a calibration device, a second output voltage of the VGA when the VGA is set at a second gain setting different from the first gain setting. The method further includes calculating, by the calibration device, an offset voltage of a signal path including the VGA using the first output voltage and the second output voltage and calculating, by the calibration device, an internal offset voltage of the VGA using the first output voltage and the second output voltage.

Abstract: An embodiment method includes measuring, by a calibration device, a first output voltage of a variable gain amplifier (VGA) when the VGA is set at a first gain setting and measuring, by a calibration device, a second output voltage of the VGA when the VGA is set at a second gain setting different from the first gain setting. The method further includes calculating, by the calibration device, an offset voltage of a signal path including the VGA using the first output voltage and the second output voltage and calculating, by the calibration device, an internal offset voltage of the VGA using the first output voltage and the second output voltage.

Abstract: A system, apparatus and method is described for dynamically boosting (increasing) the power supply voltage to an envelope tracking (ET) modulator within a transmitter system when the target/desired power amplifier voltage supply is above a predetermined threshold (e.g., equal to the available power supply of the system, such as a battery). By boosting the power input supply to the ET modulator, the modulated power supply provided to the power amplifier (PA) is also increased. This reduces or eliminates clipping that normally occurs when the target/desired PA supply voltage is greater than the available power supply voltage and reduces distortion in the transmitted signal.

Abstract: IP2 calibration efficiency can be improved by passing the calibration signal through the transceiver's duplexer instead of inserting the calibration signal directly onto transceivers receive circuit. Passing the calibration signal through the duplexer may reduce IP2 calibration periods for transceivers having less-permeable duplexers, or duplexers that provide better than average separation between the RX and TX circuits. IP2 calibration inefficiencies can also be reduced by using a binary-like search when computing the in-phase and quadrature-phase path correction coefficients of the IP2 correction code.

Abstract: A system, apparatus and method is described for dynamically boosting (increasing) the power supply voltage to an envelope tracking (ET) modulator within a transmitter system when the target/desired power amplifier voltage supply is above a predetermined threshold (e.g., equal to the available power supply of the system, such as a battery). By boosting the power input supply to the ET modulator, the modulated power supply provided to the power amplifier (PA) is also increased. This reduces or eliminates clipping that normally occurs when the target/desired PA supply voltage is greater than the available power supply voltage and reduces distortion in the transmitted signal.

Abstract: IP2 calibration efficiency can be improved by passing the calibration signal through the transceiver's duplexer instead of inserting the calibration signal directly onto transceivers receive circuit. Passing the calibration signal through the duplexer may reduce IP2 calibration periods for transceivers having less-permeable duplexers, or duplexers that provide better than average separation between the RX and TX circuits. IP2 calibration inefficiencies can also be reduced by using a binary-like search when computing the in-phase and quadrature-phase path correction coefficients of the IP2 correction code.