Abstract: A charge pump circuit for generating a negative voltage has a switched capacitor voltage inverter circuit arranged to receive at least one clock signal and generate a negative voltage therefrom; a regulation control loop providing a feedback path from the output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, wherein the regulation control loop has a filter arranged to filter the generated negative voltage; and an output arranged to output the filtered generated negative voltage.

Abstract: A signal transmitting apparatus includes: a first converting device arranged to generate an up-converted in-phase signal according to an in-phase digital signal and a first pre-distortion signal; a second converting device arranged to generate an up-converted quadrature signal according to a quadrature digital signal and a second pre-distortion signal; an amplifying device arranged to generate an amplified signal according to the up-converted in-phase signal and the up-converted quadrature signal; and a processing device arranged to generate the first pre-distortion signal according to a first combination signal combined by a cube of the in-phase digital signal and a multiplication of the in-phase digital signal and a square of the quadrature digital signal, and to generate the second pre-distortion signal according to a second combination signal combined by a cube of the quadrature digital signal and a multiplication of the quadrature digital signal and a square of the in-phase digital signal.

Abstract: A signal transmitting apparatus includes: a first converting device arranged to generate an up-converted in-phase signal according to an in-phase digital signal and a first pre-distortion signal; a second converting device arranged to generate an up-converted quadrature signal according to a quadrature digital signal and a second pre-distortion signal; an amplifying device arranged to generate an amplified signal according to the up-converted in-phase signal and the up-converted quadrature signal; and a processing device arranged to generate the first pre-distortion signal according to a first combination signal combined by a cube of the in-phase digital signal and a multiplication of the in-phase digital signal and a square of the quadrature digital signal, and to generate the second pre-distortion signal according to a second combination signal combined by a cube of the quadrature digital signal and a multiplication of the quadrature digital signal and a square of the in-phase digital signal.

Abstract: A charge pump circuit for generating a negative voltage has a switched capacitor voltage inverter circuit arranged to receive at least one clock signal and generate a negative voltage therefrom; a regulation control loop providing a feedback path from the output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, wherein the regulation control loop has a filter arranged to filter the generated negative voltage; and an output arranged to output the filtered generated negative voltage.

Abstract: A charge pump circuit for generating a negative voltage has a switched capacitor voltage inverter circuit arranged to receive at least one clock signal and generate a negative voltage therefrom; a regulation control loop providing a feedback path from the output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, wherein the regulation control loop has a filter arranged to filter the generated negative voltage; and an output arranged to output the filtered generated negative voltage.

Abstract: A charge pump circuit for generating a negative voltage has: a clock generator arranged to output at least one clock signal; a switched capacitor voltage inverter circuit including capacitive elements wherein the switched capacitor voltage inverter circuit receives the at least one clock signal and generates a negative voltage therefrom. The charge pump circuit further has a regulation control loop providing a feedback path from an output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, and an output arranged to output a generated negative voltage. The feedback path has an operational amplifier configured to generate a maximum charging supply voltage from a fed back level-shifted negative voltage and apply the maximum charging supply voltage to the input supply of the switched capacitor voltage inverter to charge at least one of the capacitive elements during a loop start up.

Abstract: A charge pump circuit for generating a negative voltage has a switched capacitor voltage inverter circuit arranged to receive at least one clock signal and generate a negative voltage therefrom; a regulation control loop providing a feedback path from the output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, wherein the regulation control loop has a filter arranged to filter the generated negative voltage; and an output arranged to output the filtered generated negative voltage.

Abstract: A charge pump circuit for generating a negative voltage has: a clock generator arranged to output at least one clock signal; a switched capacitor voltage inverter circuit including capacitive elements wherein the switched capacitor voltage inverter circuit receives the at least one clock signal and generates a negative voltage therefrom. The charge pump circuit further has a regulation control loop providing a feedback path from an output of the switched capacitor voltage inverter circuit to a supply input of the switched capacitor voltage inverter circuit, and an output arranged to output a generated negative voltage. The feedback path has an operational amplifier configured to generate a maximum charging supply voltage from a fed back level-shifted negative voltage and apply the maximum charging supply voltage to the input supply of the switched capacitor voltage inverter to charge at least one of the capacitive elements during a loop start up.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, applying a training signal having an envelope that varies with time to an input of the RF transmitter module, receiving at least an indication of instantaneous output signal values for the power amplifier module in response to the training signal, calculating instantaneous gain values based at least partly on the received output power values, and adjusting a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit: applying training signal having time-variant envelope to input of the RF transmitter module; receiving indication of instantaneous output signal value(s) for the power amplifier module in response to the training signal; and adjusting timing alignment between envelope tracking path of the envelope tracking system and transmit path of the RF transmitter module to align envelope tracking power amplifier module supply voltage to instantaneous envelope(s) of a waveform signal to be amplified by the power amplifier module, based at least partly on the received indication of the instantaneous output signal value(s) for the power amplifier module in response to the training signal.

Abstract: A predistortion circuit is for providing distortion correction in a presence of harmonics. The predistortion circuit includes an input for receiving a digital input signal; an output for providing a digital output signal to an up-conversion element that produces harmonic terms operably coupled to a non-linear device; and a processor operably coupled to an output of the non-linear device for receiving an output radio frequency signal therefrom and arranged to determine a digital correction to be applied to the digital input signal. The processor is further arranged to determine the digital correction that includes a plurality of in-phase and quadrature cross-terms of the digital input signal where terms of a same order have different co-efficients.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, determining combinations of the power amplifier supply voltage and power amplifier input power that provide a power amplifier output power equal to a target output power, obtaining battery current indications for the determined combinations of the power amplifier supply voltage and power amplifier input power, selecting a combination of the power amplifier supply voltage and power amplifier input power that provide a power amplifier output power equal to a target output power based at least partly on the obtained battery current indications therefore, and calibrating the envelope tracking system using the selected combination of the power amplifier supply voltage and power amplifier input power.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module. The method includes deriving a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain based on a gain compression factor, setting an envelope tracking path of the transmitter module into an envelope tracking mode in which mapping between the instantaneous envelope of the waveform signal and the power amplifier module supply voltage is performed using the derived mapping function, applying a training signal comprising an envelope that varies with time to the RF transmitter module, measuring a battery current, modifying the gain compression factor based on the measured battery current, and re-deriving the mapping function based on the modified gain compression factor.

Abstract: The present invention relates to a polar signal generator and method of deriving phase and amplitude components from in-phase (I) and quadrature-phase (Q) components of an input signal, wherein the I and Q components are generated at a first sampling frequency based on the input signal, and are then up-sampled in accordance with a predetermined first interpolation factor (N), to generate up-sampled I and Q components at a second sampling frequency higher than the first sampling frequency. The up-sampled I and Q components are converted into the phase and amplitude components, wherein the converting step is operated at the second sampling frequency. Moreover, the phase and amplitude components can be further up-sampled, optionally by different sampling frequencies, to a third and a fourth sampling frequency. Thereby, I-Q generation and cartesian-to-polar transformation can be performed at lower frequencies, which reduces power consumption.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module. The method includes deriving a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain based on a gain compression factor, setting an envelope tracking path of the transmitter module into an envelope tracking mode in which mapping between the instantaneous envelope of the waveform signal and the power amplifier module supply voltage is performed using the derived mapping function, applying a training signal comprising an envelope that varies with time to the RF transmitter module, measuring a battery current, modifying the gain compression factor based on the measured battery current, and re-deriving the mapping function based on the modified gain compression factor.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, determining combinations of the power amplifier supply voltage and power amplifier input power that provide a power amplifier output power equal to a target output power, obtaining battery current indications for the determined combinations of the power amplifier supply voltage and power amplifier input power, selecting a combination of the power amplifier supply voltage and power amplifier input power that provide a power amplifier output power equal to a target output power based at least partly on the obtained battery current indications therefore, and calibrating the envelope tracking system using the selected combination of the power amplifier supply voltage and power amplifier input power.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit, applying a training signal having an envelope that varies with time to an input of the RF transmitter module, receiving at least an indication of instantaneous output signal values for the power amplifier module in response to the training signal, calculating instantaneous gain values based at least partly on the received output power values, and adjusting a mapping function between an instantaneous envelope of a waveform signal to be amplified by the power amplifier module and the power amplifier module supply voltage to achieve a constant power amplifier module gain.

Abstract: A method of calibrating an envelope tracking system for a supply voltage for a power amplifier module within a radio frequency (RF) transmitter module of a wireless communication unit. The method includes, within at least one signal processing module of the wireless communication unit: applying training signal having time-variant envelope to input of the RF transmitter module; receiving indication of instantaneous output signal value(s) for the power amplifier module in response to the training signal; and adjusting timing alignment between envelope tracking path of the envelope tracking system and transmit path of the RF transmitter module to align envelope tracking power amplifier module supply voltage to instantaneous envelope(s) of a waveform signal to be amplified by the power amplifier module, based at least partly on the received indication of the instantaneous output signal value(s) for the power amplifier module in response to the training signal.

Abstract: The present invention relates to a transmission apparatus having at least two transmission branches for transmitting respective transmission signals at substantially same frequencies, and to a method of controlling such a transmission apparatus. A first oscillator circuit (62) is provided for generating a first signal at a first frequency to be used in a first transmission branch. Additionally, a second oscillator circuit (64) is provided for generating a second signal at a second frequency to be used in a second transmission branch, the second frequency being different from the first frequency. To enable transmission of the transmission signals at said substantially same frequencies, at least one frequency divider or multiplier (72, 74) is provided for dividing or respectively multiplying at least one of said first and second frequencies by a respective predetermined factor. Thereby, the first and second oscillator circuits can be operated at different frequencies, so that mutual coupling can be reduced.

Abstract: A predistortion circuit is for providing distortion correction in a presence of harmonics. The predistortion circuit includes an input for receiving a digital input signal; an output for providing a digital output signal to an up-conversion element that produces harmonic terms operably coupled to a non-linear device; and a processor operably coupled to an output of the non-linear device for receiving an output radio frequency signal therefrom and arranged to determine a digital correction to be applied to the digital input signal. The processor is further arranged to determine the digital correction that includes a plurality of in-phase and quadrature cross-terms of the digital input signal where terms of a same order have different co-efficients.