Abstract: In one form, a signal generator system such as a power amplifier system includes an amplification stage, a lowpass filter, and a controller. The amplification stage includes a first amplifier having an input for receiving an input signal, a control input for receiving a first control signal, and an output. The lowpass filter has a first input coupled to the output of the first amplifier, and an output. The controller has a first input coupled to the output of the lowpass filter, and a first output coupled to the control input of the first amplifier, wherein the controller varies the first control signal to reduce a difference between the output of the lowpass filter and a first target voltage level.

Abstract: In one form, a power amplifier system includes first and second amplification path, and a combination element. The first amplification path has an input for receiving a drive signal, and an output. The second amplification path has an input coupled to the input of the first amplification path, and an output. The second amplification path has a delay element that inserts a signal path delay with respect to the first amplification path, wherein the delay element has a delay corresponding to a harmonic that is desired to be reduced. The combination element is coupled to the output of the first amplification path and an output of the second amplification path, and provides an output signal as a sum of outputs of the first amplification path and the second amplification path.

Abstract: In one form, a power amplifier system includes first and second amplification path, and a combination element. The first amplification path has an input for receiving a drive signal, and an output. The second amplification path has an input coupled to the input of the first amplification path, and an output. The second amplification path has a delay element that inserts a signal path delay with respect to the first amplification path, wherein the delay element has a delay corresponding to a harmonic that is desired to be reduced. The combination element is coupled to the output of the first amplification path and an output of the second amplification path, and provides an output signal as a sum of outputs of the first amplification path and the second amplification path.

Abstract: In one form, a signal generator system such as a power amplifier system includes an amplification stage, a lowpass filter, and a controller. The amplification stage includes a first amplifier having an input for receiving an input signal, a control input for receiving a first control signal, and an output. The lowpass filter has a first input coupled to the output of the first amplifier, and an output. The controller has a first input coupled to the output of the lowpass filter, and a first output coupled to the control input of the first amplifier, wherein the controller varies the first control signal to reduce a difference between the output of the lowpass filter and a first target voltage level.

Abstract: A radio frequency (RF) receiver with frequency planning includes an analog receiver, a digital processor, and a clock synthesizer. The analog receiver has an input for receiving an RF input signal, and an output for providing a digital intermediate frequency (IF) signal. The digital processor has a first input for receiving the digital IF signal, a second input for receiving a clock signal, a signal output for providing an IF output signal, and a control output for providing a clock control signal. The clock synthesizer has an input for receiving the clock control signal, and an output for providing the clock signal, and is controllable to adjust a frequency of the clock signal to a selected one of a predetermined number of frequencies within a predetermined frequency range in response to the clock control signal.

Abstract: A frequency synthesizer includes a controlled oscillator configured to extend a temperature range and phase noise of the synthesizer without compromising the frequency coverage of the synthesizer. The frequency synthesizer also includes bias generation circuitry that sets a bias current of a charge pump to reduce bandwidth variations of the synthesizer. The frequency synthesizer further includes switching circuitry to dynamically turn a charge pump on and off to reduce effects of current leakage in the charge pump.

Abstract: A shielded differential inductor forms a high quality factor (high-Q) inductor that is configured to attenuate frequency spurs and/or noise from magnetic coupling generated by electrical structures on or off of a substrate as well as interference received by other components from magnetic coupling generated by the inductor. The shielded differential inductor includes a differential inductor and a shield that substantially isolates the electrical field between the inductor and the substrate to reduce substrate current loss. The shield includes sets of finger structures that extend beyond the width of the inductor and a hub and spoke configuration of ground conductors that connect the sets of finger structures to ground.

Abstract: A frequency synthesizer includes a controlled oscillator configured to extend a temperature range and phase noise of the synthesizer without compromising the frequency coverage of the synthesizer. The frequency synthesizer also includes bias generation circuitry that sets a bias current of a charge pump to reduce bandwidth variations of the synthesizer. The frequency synthesizer further includes switching circuitry to dynamically turn a charge pump on and off to reduce effects of current leakage in the charge pump.

Abstract: A radio frequency (RF) receiver with frequency planning includes an analog receiver, a digital processor, and a clock synthesizer. The analog receiver has an input for receiving an RF input signal, and an output for providing a digital intermediate frequency (IF) signal. The digital processor has a first input for receiving the digital IF signal, a second input for receiving a clock signal, a signal output for providing an IF output signal, and a control output for providing a clock control signal. The clock synthesizer has an input for receiving the clock control signal, and an output for providing the clock signal, and is controllable to adjust a frequency of the clock signal to a selected one of a predetermined number of frequencies within a predetermined frequency range in response to the clock control signal.

Abstract: A shielded differential inductor forms a high quality factor (high-Q) inductor that is configured to attenuate frequency spurs and/or noise from magnetic coupling generated by electrical structures on or off of a substrate as well as interference received by other components from magnetic coupling generated by the inductor. The shielded differential inductor includes a differential inductor and a shield that substantially isolates the electrical field between the inductor and the substrate to reduce substrate current loss. The shield includes sets of finger structures that extend beyond the width of the inductor and a hub and spoke configuration of ground conductors that connect the sets of finger structures to ground.