Abstract: The described devices, systems and methods include an integrator circuit having two separate operational modes to control a power output level delivered by the power amplifier to an antenna during start of a transmission burst. The first operational mode utilizes a wide bandwidth control loop to pre-charge a capacitor of the integrator circuit, which generates a pedestal voltage delivered to the power amplifier control input. The second operational mode utilizes a lower bandwidth control loop to ensure stable operation of the control loop during normal operation of the power amplifier.

Abstract: A method for power amplifier (PA) calibration for an envelope tracking system of a wireless device is disclosed. The method involves measuring an output power of a PA that is a part under test (PUT) at a predetermined input power. Another step includes calculating a gain equal to the output power of the PA divided by the predetermined input power. A next step involves calculating a gain correction by subtracting the calculated gain from a desired gain. Other steps include determining an expected supply voltage for the PA at the desired gain using the gain correction applied to a nominal curve of gain versus PA supply voltage, and then storing the expected supply voltage for the PA versus input power in memory.

Abstract: A front end radio architecture (FERA) with power management is disclosed. The FERA includes a first power amplifier (PA) block having a first-first PA and a first-second PA, and a second PA block having a second-first PA and a second-second PA. First and second modulated switchers are adapted to selectively supply power to the first-first PA and the second-first PA, and to supply power to the first-second PA and the second-second PA, respectively. The first and second modulated switchers have a modulation bandwidth of at least 20 MHz and are both suitable for envelope tracking modulation. A control system is adapted to selectively enable and disable the first-first PA, first-second PA, the second-first PA, and the second-second PA. First and second switches are responsive to control signals to route carriers and received signals between first and second antennas depending upon a selectable mode of operation such as intra-band or inter-band operation.

Abstract: The present disclosure relates to IQ modulation circuitry that during a data burst mode, modulates an RF carrier signal to provide a modulated RF signal, which is used for transmission of a transmit slot. During the data burst mode, a maximum energy spectrum peak of the modulated RF signal is about coincident with an RF carrier frequency of the RF carrier signal to comply with communications protocols. Further, during an energy-shifted ramp-down mode, which is coincident with ramp-down of the modulated RF signal, the IQ modulation circuitry modulates the RF carrier signal to provide the modulated RF signal. During the energy-shifted ramp-down mode, the maximum energy spectrum peak of the modulated RF signal is shifted away from the RF carrier frequency of the RF carrier signal to mitigate the effects of preparing for receiving an RF receive signal.

Abstract: The exemplary embodiments include a radio frequency antenna switch configured to reject harmonic frequencies. In addition, the harmonic-rejected radio frequencies of the radio frequency antenna switch may be tuned by use of a capacitor array. The capacitor array may be configured with fuse elements or by control logic.

Abstract: The present invention relates to a dual radio frequency (RF) receiver circuit that includes a first RF mixer and a second RF mixer. The first and second RF mixers may be fed from a common local oscillator or from two separate local oscillators. When fed from two separate local oscillators and when the first and second RF mixers are receiving the same or nearly the same RF channel, the frequency of the RF channel is less than the frequency of one local oscillator and is greater than the frequency of the other local oscillator. This arrangement separates the frequencies of the local oscillators, thereby reducing noise, instability, or both, which may otherwise de-sensitize the dual RF receiver circuit.

Abstract: A dual FET detector having a common RF input and a common detector output for two detector circuits is provided. The first detector circuit is optimized for detecting lower RF signal levels while the second detector circuit is optimized for detecting higher RF signal levels. A detector output voltage output from the common detector output is a composite signal made up of the individual contributions of the two detector circuits. A control circuit receives a feedback signal derived from the detector output voltage, and uses the feedback signal to control a transition between urging a predominance of the contribution to the detector output voltage from one of the detector circuits to the other. The control of the transition between the detector circuits ensures that whichever of the two detector circuits is best optimized for a particular RF signal level will contribute the most to the detector output voltage.

Abstract: The present invention is a radio frequency (RF) receiver that uses an RF mixer for tuning to desired frequency bands. The RF receiver down converts a received RF signal into a very low intermediate frequency (VLIF) signal. When receiving a desired RF signal, the frequency of the resulting VLIF signal is called the desired VLIF frequency, and is based on the signal strength of the received RF signal. In one embodiment of the present invention, the desired VLIF frequency is selected to be one of two VLIF frequencies, and is inversely related to the signal strength of the received RF signal. For example, a higher desired VLIF frequency is selected when receiving lower signal strength RF signals to increase effective receiver sensitivity. A lower desired VLIF frequency is selected when receiving higher signal strength RF signals to improve image rejection.

Abstract: The exemplary embodiments include methods, computer readable media, and devices for calibrating a non-linear power detector of a radio frequency device based upon measurements of the non-linear power detector output and the associated power amplifier output level, and a set of data points that characterize a nominal non-linear power detector. The set of data points that characterize the nominal non-linear power detector is stored in a calibration system memory as nominal power detector output data. The measured non-linear power detector outputs, power amplifier output levels, and the nominal power detector output data is used to determine a power detector error function that characterizes the difference between the response of the non-linear power detector and the nominal non-linear power detector. The power detector error function and the nominal power detector output data are used to develop a calibrated power detector output data set that is stored in the non-linear power detector.

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The battery resistance is thereafter updated as desired and used as an indicator of remaining battery-life or power of the battery of the mobile terminal.

Abstract: A front end radio architecture (FERA) is disclosed that includes a transmitter block coupled to a power amplifier (PA) via first and second input terminals. A first split-band duplexer is coupled to a first output terminal of the PA and a second split-band duplexer is coupled to a second output terminal of the PA. The PA includes a first amplifier cell and a second amplifier cell that when coupled to the first and second split-band duplexers makes up first and second transmitter chains. Only one of the first and the second transmitter chains is active when a first carrier and a second carrier have a frequency offset that is less than an associated half duplex frequency within a same split-band duplex band, thus preventing third order inter-modulation (IMD) products from falling within an associated receive channel. Otherwise, the first and the second transmitter chains are both active.

Abstract: A transmitter includes a polar modulator that creates phase and amplitude signals which in turn drive a power amplifier. To compensate for AM to PM conversion of the amplitude signal into the amplified signal, a compensation signal is generated from the amplitude signal and combined with the phase signal such that when amplified, the compensation signal cancels the AM to PM conversion. The compensation signal may have an offset term, a linear term, a quadratic term, and a cubic term. A second embodiment comprises a technique by which AM to AM conversion may concurrently be addressed using a second compensation signal.

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The resistance of the battery is thereafter used to compensate for battery droop during over-voltage detection and correction for one or more subsequent transmit bursts.

Abstract: A system and method for calibrating Amplitude Modulation to Phase Modulation (AM/PM) compensation circuitry in a mobile terminal operating according to a polar modulation scheme are provided. In general, during ramp-up for a transmit burst, measurements of a phase error between an input and output of power amplifier circuitry in the transmit chain are obtained. Using the phase error measurements, the AM/PM compensation circuitry is calibrated and used to provide AM/PM compensation for the same transmit burst. By calibrating the AM/PM compensation circuitry using the phase error measurements obtained during ramp-up, the AM/PM compensation circuitry is calibrated for the desired frequency band, sub-band, and power control level setting as well as for the current load conditions at the antenna and ambient temperature.

Abstract: A system and method for detecting and correcting over-current and/or over-voltage conditions in power amplifier circuitry in a transmit chain of a mobile terminal are provided. In general, over-current detection and correction circuitry combines a current detection signal indicative of a current provided to or drained by the power amplifier circuitry during ramp-up for a transmit burst and a substantially inverse current ramping profile to provide a first constant value. The first constant value is compared to a current threshold or limit value to determine whether an over-current condition exists. If an over-current condition exists, the over-current detection and correction circuitry operates to reduce the output power of the power amplifier circuitry during ramp-up for the transmit burst to correct for the over-current condition. In a similar manner, over-voltage detection circuitry operates to detect and correct over-voltage conditions during ramp-up for the transmit burst.

Abstract: An over-voltage detection and correction system for a transmitter of a mobile terminal that accounts for battery droop during a transmit burst is provided. In general, prior to ramp-up for a first transmit burst, a voltage of the battery of the mobile terminal at a no-load condition is measured. After ramp-up for the transmit burst, the voltage of the battery is measured at full-load, and a current provided to a power amplifier of the transmitter at full-load is detected. Based on the measured voltage of the battery at no-load, the measured voltage of the battery at full-load, and the detected current provided to the power amplifier at full-load, a resistance of the battery is determined. The battery resistance is thereafter updated as desired and used as an indicator of remaining battery-life or power of the battery of the mobile terminal.

Abstract: A transmitter includes a polar modulator that creates phase and amplitude signals which in turn drive a power amplifier. To compensate for AM to PM conversion of the amplitude signal into the amplified signal, a compensation signal is generated from the amplitude signal and combined with the phase signal such that when amplified, the compensation signal cancels the AM to PM conversion. The compensation signal may have an offset term, a linear term, a quadratic term, and a cubic term. A second embodiment comprises a technique by which AM to AM conversion may concurrently be addressed using a second compensation signal.

Abstract: A transmitter includes a polar converter to generate an amplitude signal and a phase signal, which in turn is converted to a frequency signal. The amplitude signal is directed to a compensator and a compensation signal is generated. The compensation signal is combined with the amplitude signal and the combined signal is presented to the power amplifier. The AM to AM conversion is reduced such that the output signal of the power amplifier contains substantially no spurious components.

Abstract: A fractional-N based Automatic Frequency Control (AFC) system for a mobile terminal is provided. In general, automatic frequency control is implemented in a frequency synthesizer to correct or compensate for a frequency error of an associated reference oscillator. The frequency synthesizer includes a first fractional-N phase-locked loop (FN-PLL) generating a baseband clock signal used by a baseband processor of the mobile terminal, a second FN-PLL generating a receiver local oscillator signal used by a receiver of the mobile terminal to downconvert a received radio frequency signal to a desired frequency, and a translational PLL generating a transmitter local oscillator signal used by a transmitter of the mobile terminal to provide a radio frequency transmit signal. The automatic frequency control is performed by applying a digital correction value, which is preferably multiplicative, to fractional-N dividers of the first and second FN-PLLs.

Abstract: A polar transmitter that is configurable as either a closed loop polar transmitter or an open loop polar transmitter is provided. In general, the polar transmitter is configured as an open loop polar transmitter when operating at an output power level less than a predetermined threshold and as a closed loop polar transmitter when operating at an output power greater than the predetermined threshold.