There is provided a technique for calibrating the envelope tracking circuitry of the wireless interface of an electronic device to compensate for any delay mismatch between the IQ signal path and the envelope path. Thee desired levels of input test signals are determined to assure that they are sensitive to any delay mismatch which may be in the system. The propagation delay from the signal generator to the signal analyzer of the envelope tracking system is estimated and delay compensation is performed. To reduce the noise of the measurement, distortion in the received signal may also be determined and noise compensation may also be performed. Based on these determinations, the envelope tracking circuitry may be calibrated by introducing an appropriate delay in either the envelop path or the IQ signal path.

A digital quadrature modulator holds local oscillator circuitry configured to provide local oscillator signals, and local oscillator polarity logic circuitry configured to select an In-phase and a Quadrature local oscillator signal according to a sign bit of an In-phase control word and a sign bit of a Quadrature control word, respectively. The modulator holds a number of local oscillator control logic circuits, each configured to generate a conditioned signal by gating one or both of the selected local oscillator signals according to values of the In-phase control word and/or values of the Quadrature control word. The modulator has one or more sets of switched-capacitor units, where each unit has an output provided by an output capacitor, and where a signal at the input side of the output capacitor is controlled by a conditioned signal. The outputs of at least two of the switched-capacitor units are combined in a common node.

A circuit includes a first transistor comprising a gate, a source, and a drain, and an inductor coupled between the gate and the source of the first transistor, wherein the source is further coupled to a current source and the gate is further coupled to an amplifier.

A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

Methods and systems for a pseudo-differential low-noise amplifier at Ku-band may comprise a low-noise amplifier (LNA) integrated on a semiconductor die, where the LNA comprises differential pair transistors with an embedded inductor tail integrated on the semiconductor die. The embedded inductor tail may comprise: a first inductor with a first terminal capacitively-coupled to a gate terminal of a first transistor of the differential pair transistors and a second terminal of the first inductor coupled to second, third, and fourth inductors. The second inductor may be coupled to a source terminal of the first transistor of the differential pair transistors, the fourth inductor may be coupled to a source terminal of the second transistor of the differential pair transistors, and the third inductor may be capacitively-coupled to a gate terminal of the second transistor of the differential pair transistors and also to ground. The second inductor may be embedded within the first inductor.

An apparatus for providing a supply control signal for a supply unit, the supply unit being configured to provide a variable controlled power supply to the power amplifier. The apparatus includes a determination module configured to determine a deviation of a signal from at least one nominal value; and an adjustment module configured to provide the supply control signal after an adjustment based on the determined deviation.

A radio frequency (RF) transmitter includes a power amplifier comprising a plurality of power amplifier cells. At least one digital signal processing module of the RF transmitter is operably coupled to the power amplifier and comprises at least one digital pre-distortion component arranged to apply at least one digital pre-distortion codeword to the plurality of power amplifier cells, wherein the at least one digital pre-distortion codeword is applied to at least one of the plurality of power amplifier cells via a digital filter. A combiner is arranged to combine outputs of the plurality of power amplifier cells thereby generating an analogue RF signal for transmission over an RF interface based at least partly on the digitally filtered at least one digital pre-distortion codeword.

Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

In order to realize a power-saving power amplifier compatible with Carrier Aggregation technology using a plurality of bands, with a small size and low cost, while improving the amplitude accuracy and power efficiency, a transmission device of the present invention comprises: a modulation means that generates, from a baseband signal corresponding to each of the plurality of bands, a first and a second constant-envelope signals having different phases; a power amplification means that amplifies respective ones of the first and second constant-envelope signals generated by the modulation means; and a combining means that combines together the first and second constant-envelope signals amplified by the power amplification means and thereby generating an RF signal in which amplitude information contained in each of the baseband signals corresponding to respective ones of the plurality of bands is restored.

Apparatus (1) comprises envelope signal amplification circuitry (11) configured to receive an input envelope signal (ENV_in) indicative of an envelope of an input radio frequency signal (RF_in) and to output an amplified envelope signal (ENV_amp); and a radio frequency power amplifier (12) configured to receive a radio frequency control signal which is dependent on the input radio frequency signal(RF_in) and the input envelope signal (ENV_in), using the amplified envelope signal (ENV_amp) as its supply voltage, to output an amplified radio frequency signal (RF_amp). A method for amplification the radio frequency signal is also provided.