Future Wei Technologies, Inc.

Huawei Technologies Co., Limited

Mstar Semiconductor, Inc.

Rf Micro Devices, Inc.

St-ericsson Sa

Wael Al-Qaq

Hong Jiang

Zhihang Zhang

Dennis Mahoney

Jamil Mark Forrester

Min Yi

Matthew M Kostelnik

Paul Brey

Xiaobao Yu

Nadim Khlat

Nikolaus Klemmer

Pallab Midya

Ryan Lee Bunch

Brian Baxter

Robert Irvine

Eric Sung

Robert Grant Irvine

Matthew Martin Kostelnik

Matthew Kostelnik

A circuit includes a polar transmitter to generate a radio frequency output from amplitude and phase signal components. The polar transmitter includes an amplifier to combine amplitude and phase signal components. A processor is coupled to the polar transmitter to provide the amplitude and phase signal components. The processor includes: a digital modulation circuit to generate a modulated digital signal including in-phase and quadrature signal components and a correction circuit to calculate and apply a complex digital offset for local oscillator feedthrough of the amplifier. The complex digital offset includes an in-phase offset correction factor and a quadrature offset correction factor.

Polar transmitter with feedthrough compensation

A method includes producing a plurality of TX LO signals by a first LO generator comprising a first frequency doubler and a first frequency divider, the first frequency doubler configured to receive a VCO signal having a first frequency and generate a first signal fed into the first frequency divider, the first signal having a second frequency that is twice the first frequency, producing a plurality of MRX LO signals by a second LO generator comprising a second frequency doubler and a second frequency divider, the second frequency doubler configured to receive the VCO signal and generate a second signal fed into the second frequency divider, the second signal having the second frequency, configuring the TX to operate at a first LO frequency equal to the second frequency, and configuring the MRX to operate at a second LO frequency equal to the first frequency through disabling the second frequency doubler.

Spur compensation method and system

Techniques are presented to improve the accuracy of and reduce the time required for calibration of an in-phase/quadrature (I/Q) transmission circuit. A measurement receiver measures the I/Q mismatch, where an RF phase shift is introduced to distinguish between the transmitter and measurement receiver I/Q mismatches. Rather than assuming an amount of introduced phase shift, a measurement is used to estimate the phase shift. This phase estimate is then used to determine and correct the I/Q mismatch in the transmitter and measurement receiver. An iterative process can be used to improve the I/Q correction factors. Using simple signal processing to measure the phase shift during calibration and to perform the image calibration calculations, the phase shifter requirements can be significantly relaxed, resulting in faster design time and reduced design area/cost. This approach results in reduced calibration time, thus contributing to reduced factory production time and enabling faster live mode image calibration.

Transmitter image calibration using phase shift estimation

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.

System and method for hybrid transmitter

A system and method for transmitting and for detecting a transmission power level of a carrier of aggregated carrier signals is configured to generate a plurality of carrier signals as a carrier aggregated signal and to generate an outgoing radio frequency (RF) signal based on the carrier aggregated signal and to produce a feedback signal based the outgoing RF signal. The system process the feedback signal by down converting a first carrier signal within the feedback signal from RF, canceling a down converted harmonically-related signal or an ADC Fs related signal of a second carrier of the carrier aggregated signal and producing a signal representative of the output power of the first carrier of the carrier aggregated signal within the feedback signal.

CA power measurement

An apparatus and method are provided for setting a local oscillator duty ratio based on an image distortion level. A first signal is transmitted utilizing a first X-phase path of a transmitter. Further, an image distortion level is measured in connection with the first signal. Based on the measurement, a duty ratio of a local oscillator is set, for reducing a distortion in connection with a transmission of a second signal utilizing a second Y-phase path of the transmitter.

Apparatus and method for setting a local oscillator duty ratio based on an image distortion level

Techniques are presented to improve the accuracy of and reduce the time required for calibration of an in-phase/quadrature (I/Q) transmission circuit. A measurement receiver measures the I/Q mismatch, where an RF phase shift is introduced to help distinguish between the transmitter and measurement receiver I/Q mismatches. Rather than assuming an amount of introduced phase shift, a measurement is used to estimate the phase shift. This phase estimate is then used to determine and correct the I/Q mismatch in the transmitter and measurement receiver. An iterative process can be used to improve the I/Q correction factors. Using simple signal processing to measure the phase shift during calibration and using it to carry out the image calibration calculations, the phase shifter requirements can be significantly relaxed, resulting in faster design time and reduced design area/cost. This approach results in reduced calibration time, thus contributing to reduced factory production time and enabling faster live mode image calibration.

An apparatus for testing a circuit includes a source signal input configured to receive a source signal, an evaluation signal input configured to receive an evaluation signal, and a coefficient extractor configured to extract a plurality of coefficients of a preselected polynomial representing the evaluation signal and the source signal. A weight factor storage contains a plurality of weight factors corresponding to frequency filters. An Adjacent Channel Power Ratio (ACPR) calculator is configured to calculate an ACPR value from the evaluation signal and the source signal by applying the plurality of weight factors from the weight factor storage to the plurality of coefficients the plurality of weight factors selected according to a main channel frequency range and an adjacent channel frequency range, and determining whether the ACPR value is within an acceptable range and generating a corresponding indication.

Transmitter linearity built-in-self-test

A wireless communication device includes one or more transmitter (TX)-receiver (RX) pairs, one or more RX distortion estimators, and a combiner. A first RX distortion estimator receives a first TX signal corresponding to a first TX of the first TX-RX pair and a second TX signal corresponding to a second TX of a second TX-RX pair. The first RX distortion estimator processes the first TX signal and the second TX signal based on a first base function set including at least one base function to generate a first distortion signal set including at least one distortion signal. Then, the first RX distortion estimator processes the first distortion signal set to generate a first RX correction signal. The wireless communication device's combiner generates a first distortion compensated RX signal by compensating for distortion in a first RX signal of the first TX-RX pair based on the first RX correction signal.

Inter-band distortion and interference mitigation within communication systems

A transmitter includes a power amplifier coupled to amplify an input signal and provide an output signal. A radio frequency coupler is coupled to receive the output signal and provide a measured signal on a coupler output. A measurement receiver multiplexor is coupled to receive the measured signal on the coupler output to produce either a non-phase adjusted signal or a phase adjusted signal on one of a plurality of multiplexor outputs. Multiple receiver paths are coupled to the plurality of multiplexor outputs to receive either the non-phase adjusted signal or the phase adjusted signal. Receive path processing circuitry is configured to produce in-phase and quadrature phase digital signals based on the plurality of multiplexor outputs to digital processing circuitry to cancel 3or 3and 5order measurement receiver distortions.

Measurement receiver harmonic distortion cancellation

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.

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Oak Ridge, NC, United States of America

Wael Al-Qaq