摘要:
A fractional-N offset phase locked loop (FN-OPLL) is provided. The FN-OPLL includes a fractional divider, a phase detector, a loop filter, a voltage controlled oscillator (VCO), and feedback circuitry. Combiner circuitry combines an initial fractional divide value and a modulation signal to provide a combined fractional divide value. Based on the combined fractional divide value, the fractional-N divider divides a reference frequency and provides a divided reference frequency to the phase detector. The phase detector compares a phase of the divided reference frequency to a phase of a feedback signal to provide a comparison signal. The comparison signal is filtered by the loop filter to provide a control signal to the VCO, where the control signal controls a frequency of an output signal of the VCO. The output signal is processed by the feedback circuitry to provide the feedback signal to the phase detector.
摘要:
A polar modulator creates an amplitude signal and a frequency signal and digitally adjusts the signals so that the frequency and amplitude signals arrive at the power amplifier at the appropriate times. A digital predistortion filter is applied to the frequency signal. The frequency signal is then provided to a single port of a fractional N divider in a phase locked loop. The output of the phase locked loop drives an input of the power amplifier while the amplitude signal is converted to an analog signal and controls the power supply input of the power amplifier.
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:
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.
摘要:
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.
摘要:
A system and method are provided for transitioning between modulation formats in adjacent transmit bursts. The system includes a modulation system having a data interface, first modulation circuitry operating according to a first modulation format, and second modulation circuitry operating according to a second modulation format. During a transition between a first transmit burst in the first modulation format and a second transmit burst in the second modulation format, the data interface receives a timing signal signifying a start of data for the second transmit burst. In response to the timing signal, the second modulation circuitry resets, and the data interface delays the data for the second transmit burst by a modulator delay time. By delaying the data for the second transmit burst, a glitch caused by resetting the second modulation circuitry arrives at the output of the second modulation circuitry prior to the data for the second transmit burst.
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 dual mode wireless device in which a coefficient generator (42) generates parameter values for a GSM waveform, based on transmitted sequences of digital data values from a GSM unit (34), using a multiplierless operation, and a waveform generator 44 generating the GSM waveform using the generated parameter values. The coefficient generator includes adder sections (132, 134, 136), each having corresponding adders (142, 144, 146) and multipliers (148, 150, 152), register sections (154, 156, 158), each containing parameters corresponding to a modulator (48), and transmit data registers (TXDATA[5]-TXDATA[0]) sequentially receiving the digital data values from the GSM unit. The coefficient generator generates the parameter values for the GSM waveform by multiplying each of the parameters in the register sections by a one or a negative one, responsive to the digital data values in the transmit data registers, and adding the resulting products to form corresponding coefficient generator output values.
摘要:
A system (100 or 200) includes a first AGC stage (102) having a programming input and a gain input. A second AGC stage (104 or 210 and 234) is coupled in a common path with the first AGC stage, the second AGC stage having a programming input and a gain input. The first and second AGC stages are programmed by respective programming signals to produce independent gain characteristics responsive to a common gain signal at their respective gain inputs.