摘要:
The present disclosure relates to RF circuitry having delay locked loop (DLL) circuitry that may be used to measure amplitude modulation-to-phase modulation (AMPM) distortion of an RF power amplifier during factory calibration or during real time operation of the RF circuitry. During a calibration mode, the DLL circuitry may be calibrated using a reference clock signal. During a phase measurement mode, the DLL circuitry may use the reference clock signal, which is representative of an RF input signal to the RF power amplifier, and a feedback signal, which is representative of an RF output signal from the RF power amplifier, to measure a phase difference between the RF input signal and the RF output signal. By measuring the phase difference at different amplitudes of the RF output signal, the AMPM distortion of the RF power amplifier may be determined and used to correct for the AMPM distortion.
摘要:
The present disclosure relates to multi-mode RF circuitry using a single IQ modulator topology that may support different communication standards, including enhanced data rates for global system for mobile communications evolution (EDGE) and EDGE evolution by dividing certain modulation functions between a frequency synthesizer and an IQ modulator. Specifically, during a standard modulation mode, which may be used to support many communications standards, the frequency synthesizer provides an un-modulated RF carrier signal to the IQ modulator, which either phase modulates or phase and amplitude modulates the un-modulated RF carrier signal to provide a standard modulated RF signal. During a small signal polar modulation mode, which may be used to support the EDGE and EDGE evolution protocols, the frequency synthesizer provides a phase-modulated RF carrier signal to the IQ modulator, which may or may not amplitude modulate the phase-modulated RF carrier signal to provide a small signal polar modulated RF signal.
摘要:
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.
摘要:
The present invention provides a receiver frontend that eliminates static and dynamic DC errors and has improved second order intermodulation distortion (IMD2) performance. The receiver frontend includes a first mixer that multiplies a received signal and a first local oscillator (LO) signal to produce an intermediate frequency (IF) signal. A second mixer multiplies the IF signal and a second LO signal to produce an output signal. A first divider circuit divides a reference signal from a reference oscillator by a first divisor N to produce the first LO signal, and a second divider circuit divides the reference signal by a second divisor M to produce the second LO signal. Preferably, the first and second divisors N and M are each integers greater than one (1), and the second divisor M is not an integer multiple of the first divisor N.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.