Broadcom Corporation

Meng-An Pan

Ahmadreza Rofougaran

Stephen Wu

Brima Babatunde Ibrahim

Maryam Rofougaran

Hung-Ming Chien

Jacob Jude Rael

Shahla Khorram

Shervin Moloudi

William T Colleran

Masood Syed

Arya Behzad

Hooman Darabi

Ali Afsahi

Vikram Magoon

Syed Masood

Ed Chien

Mohyee Mikhemar

Ahmad Mirzaei

Rahul Magoon

Bojko F Marholev

Yuyu Chang

Hung-Ming Chien (Ed Chien)

Jacob Rael

A transmitter circuit with a passive mixer network includes a first outbound signal path configured to carry a first outbound signal. The transmitter circuit includes a second outbound signal path configured to carry a second outbound signal. The transmitter circuit includes N passive mixers coupled to the first and second outbound signal paths and configured to up-convert the first and second outbound signals from a first frequency to a second frequency based on a clock cycle, where N is a positive even integer. The first and second outbound signals are passed through the N passive mixers during each phase of 2*N phases in the clock cycle. The transmitter circuit also includes N radio frequency signal paths coupled to an output of respective ones of the N passive mixers and configured to receive the first and second outbound signals in the second frequency during each phase of the clock cycle.

Transmitter diversity with a passive mixer network

Disclosed are various embodiments for transmitting radio frequency signals. A radio frequency transmitter may be configured to generate an analog signal comprising an in-phase component and a quadrature-phase component. The in-phase component and the quadrature-phase component of the analog signal may be provided to multiple radio frequency processing chains. One of the radio frequency processing chains may generate an output radio frequency signal based on the in-phase component and the quadrature-phase component.

Method and system for a linearized transmitter including a power amplifier

A transmitter RF front-end integrated on a single substrate is enabled to determine whether associated IF amplification stage provides a required transmission gain for transmitting an output signal of an application. A dedicated power amplifier driver within the transmitter RF front-end is configured to provide additional gain, when needed based on the determination, to meet the required transmission gain for transmitting the output signal. The associated IF amplification stage comprises an upconversion mixer and a lowpass filter (LPF). The upconversion mixer may be implemented as an active mixer or a passive mixer. The upconversion mixer and the dedicated power amplifier driver are enabled to operate in 2.44 gigahertz. A maximum gain provided by the associated intermediate frequency (IF) amplification stage for transmitting the output signal is determined to decide the additional gain provided by the dedicated power amplifier driver by comparing with the required transmission gain.

Method and system for a dynamic transmission gain control using a dedicated power amplifier driver in a radio frequency transmitter

A center frequency of an adjustable filter is controlled to achieve a compromise between DC offset rejection and image rejection.

Programmable if frequency filter for enabling a compromise between DC offset rejection and image rejection

According to one exemplary embodiment, a method of preventing harmonics from causing distortion in a communications system includes feeding a test signal through a pre-distortion circuit in the communications system to a transmitter in the communications system. The method continues by transmitting a distorted output signal produced by the transmitter to an analyzer, analyzing the distorted output signal to identify one or more undesired harmonics, and generating and sending calibration data from the analyzer to calibrate the pre-distortion circuit, thereby preventing the one or more undesired harmonics from causing distortion in the communications system. In one embodiment, a system to prevent harmonics from causing distortion in a communications system includes a pre-distortion circuit, a transmitter, and an analyzer configured to identify one or more undesired harmonics and to generate and send calibration data to prevent the undesired harmonics from causing distortion.

Method and system to prevent harmonics from causing distortion in a communications system

A method and apparatus is disclosed to optimize one or more operational parameters of a communications transmitter to reduce undesirable noise and/or interference embedded within a transmitted communications signal resulting from one or more imperfections. A baseband processor selects one or more calibration signals to allow for optimization of one or more statistical parameters. A calibration module determines the one or more statistical parameters of the transmitted communications signal in response to the one or more calibration signals. The calibration module provides one or more compensation parameters indicative of the one or more statistical parameters to the baseband processor module. The baseband processor adjusts the one or more operational parameters of the communications transmitter in response to the one or more compensation parameters. The calibration module and the baseband processor continue to determine the one or more statistical parameters and to adjust the one or more operational parameters in a similar manner until the one or more statistical parameters are optimized.

Calibration of a communications transmitter to optimize DC offset rejection and image rejection

Aspects of compensating for transmitter output power may comprise sampling an on-chip transmitter circuit temperature at various time instants and determining a feedback temperature compensation value. At least one digital-to-analog converter may be adjusted by utilizing the feedback temperature compensation value, which may correspond to the sampled temperature. The digital-to-analog converter may be an I-component digital-to-analog converter and/or a Q-component digital-to-analog converter. At least a portion of the on-chip transmitter circuit may be characterized to determine power output dependence of the on-chip transmitter circuit on temperature variation of the on-chip transmitter circuit. Based on this characterization, a feedback temperature compensation value that may correspond to the sampled temperature may be used to adjust the digital-to-analog converter. The feedback temperature compensation value may be, for example, from a lookup table or an algorithm.

Method and system for transmitter output power compensation

A method and system for output common mode control for reducing DC offset for an IF mixer that downconverts a received signal to DC without introducing additional offset is provided. Aspects of the method may comprise averaging signals having an output common mode DC level, which are generated from an output of the mixer. This determined average may then be compared to a reference voltage. The reference voltage may be an output common mode DC level required for baseband processing. The output common mode DC level may be corrected at an input of the mixer for signals that may subsequently be generated from an output of the mixer by utilizing results from the comparison. The corrected common mode DC offset level may be fed back to an input of the mixer.

Method and system for output common mode control for reducing DC offset for an IF mixer that downconverts a received signal to DC without introducing additional offset

Aspects of a method and system for an integrated LC resonant current gain boosting amplifier may include amplifying within a chip, via an on-chip LC current gain circuit, an alternating current (AC) generated by an on-chip voltage-to-current converter, and converting within the chip, via an on-chip current-to-voltage circuit; the amplified alternating current to an output voltage. The on-chip LC current gain circuit comprises only passive components, which may include one or more resistors, one or more capacitors, and one or more inductors.

Method and system for an LC resonant current gain boosting amplifier

A method and system for wireless communication is provided and may include generating a single analog quadrature signal in a chip including RF transmitters and receivers using a baseband processor, and generating output RF signals based on the quadrature signal in corresponding RF transmitters. The output RF signals may be communicated to the RF receivers via a feedback path including circuitry external to the RF receivers. The dedicated circuitry may include a transmit/receive switch and/or an on-chip or off-chip balun. The quadrature signal may include in-phase and quadrature-phase components. The output RF signal communicated via the feedback path may be down-converted utilizing mixers in the RF receivers and communicated to the baseband processor. Distortion in the quadrature signal may be estimated utilizing the communicated down-converted output RF signals and subsequently generated quadrature signals may be predistorted based on the distortion estimation.

Linearized transmitter including a power amplifier

Methods and systems for a transmitter LOFT cancellation scheme that maintains IQ balance are disclosed. Aspects of one method may include providing current compensation to both differential inputs of a mixer for each of I and Q channels. An initial current compensation of X units may be provided, followed by subsequent compensation as needed. The initial compensation may be provided to each differential input of the mixers used for I and Q channels. The subsequent current compensation for the I channel may be independent of the subsequent current compensation for the Q channel. Subsequent current compensation to a first differential input for a mixer may be increased by Y units while decreasing current compensation to the second differential input of the mixer by Y units. In this manner, the DC common mode level for the mixer may remain the same at the initial DC compensation current of X units for both mixers.

Method and system for a transmitter loft cancellation scheme that maintains IQ balance

A transmitter includes a dual mode modulator and an amplifier coupled to the dual mode modulator. The dual mode modulator implements a linear modulation scheme during a first mode of the modulator to produce a variable envelope modulated signal. The dual mode modulator implements a non-linear modulation scheme during a second mode of the modulator to produce a constant envelope modulated signal. The amplifier is biased as a linear amplifier during the first mode of the modulator and is biased as a non-linear amplifier during the second mode of the modulator. A feed-forward connection between the dual mode modulator and the amplifier is used to indicate a change in modulation mode and to adjust the bias of the amplifier. A power of the constant envelope modulated signal is increased such that an operating point of the amplifier remains substantially constant during the first and second modes of the modulator.

Linear and non-linear dual mode transmitter

A RF transmitter is operable to transmit a signal at a frequency specified by the Bluetooth protocol. A passive upconversion mixer, which comprises a pair of MOSFET switches, is utilized inside the RF transmitter. The passive upconversion mixer is operable to receive analog local oscillator (LO) signals to be utilized for controlling operation of each of the pair of MOSFET switches to transmit signals with maximum gain. A MOS threshold voltage Vand a DC component of a received baseband signal, V, are determined for each of the pair of MOSFET switches. The determined Vand the determined Vof the received baseband signal are combined such as V+Vand compared with a DC component of the received LO signals, V. The Vis set equal to V+V, accordingly, to provide maximum gain from the passive upconversion mixer for signal transmission.

Method and system for obtaining maximum gain of a passive upconversion mixer utilized in a transmitter

An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

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Irvine, CA, United States of America

Meng-An Pan