Abstract: Radio frequency communication systems with a combined antenna impedance tuning and antenna multiplexing functionality are provided. In certain embodiments, a packaged radio frequency module includes an antenna multiplexer and an antenna impedance tuner. The module can be configured to provide impedance matching between one or more radio frequency front end modules and an antenna. The antenna impedance tuner can supplement antenna tuning provided by an antenna aperture separately connected to the antenna.

Abstract: Envelope tracking systems with modeling for power amplifier supply voltage filtering are provided herein. In certain embodiments, an envelope tracking system includes a supply voltage filter, a power amplifier that receives a power amplifier supply voltage through the supply voltage filter, and an envelope tracker that generates the power amplifier supply voltage. The power amplifier provides amplification to a radio frequency (RF) signal that is generated based on digital signal data, and the envelope tracker generates the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the RF signal. The envelope tracking system further includes digital modeling circuitry that models the supply voltage filter and operates to digitally compensate the digital signal data for effects of the supply voltage filter, such as distortion.

Abstract: The described devices, systems and methods include a voltage controlled oscillator. The voltage controlled oscillator includes a fine-tuning varactor network, a switch capacitor array having a first plurality of binary capacitor array elements and a second plurality of thermometer code capacitor array elements, and a tank inductor network including a first inductor in parallel with a second inductor.

Abstract: A system includes an interleaved analog-to-digital converter (ADC) comprising a plurality of sub-ADCs, where each of the plurality of sub-ADCs has an adjustable timing. The system includes a data analyzer that analyzes an output of the interleaved ADC, that estimates timing mismatches of the plurality of sub-ADCs, and that corrects the timing mismatches by adjusting the adjustable timing of one or more of the plurality of sub-ADCs based on the estimated timing mismatches.

Abstract: Methods and apparatus for blind detection and correction of interleaving errors using all-digital processing of data output by multiple sub-ADCs of a time-interleaved ADC are disclosed. The methods and apparatus detect and correct frequency-dependent timing and gain mismatches of the sub-ADCs of the time-interleaved ADC using a novel multiple-input multiple-output (MIMO) filter structure. Additionally, a novel adaptive sampling frequency hopping scheme is proposed to achieve uninterrupted data conversion by the time-interleaved ADC during transient time of ADC clock frequency switching.

Abstract: A phase locked loop and power amplifier are integrated on a single chip. To eliminate cross-talk between the components, a frequency translation block is introduced to change the output frequency of the PLL. To isolate the components from unwanted feedback, a high isolation buffer is introduced between the components. To further isolate the components, the voltage supply domains for each component are physically separated. Each separate voltage supply domain can include a separate high isolation ring, separate voltage regulator, and separate bandgap reference.

Abstract: The present invention relates to a digitally-controlled crystal oscillator (DCXO) circuit having control circuitry, an active core, and a pair of thermometer-coded switched-capacitor circuits (TCSCCs), each of which is coupled to the active core and to a crystal. The active core, the crystal, and the pair of TCSCCs form a DCXO, which provides an output signal having an output frequency. Each TCSCC includes multiple capacitive elements, which are selected by a respective control signal from the control circuitry to control the output frequency. The DCXO circuit may be integrated into a digital integrated circuit (IC) without need for a digital-to-analog converter (DAC), and may be used with a wide range of crystal types. By using thermometer-coding, the pair of TCSCCs provides monotonic frequency tuning behavior. Further, by utilizing different types of tuning steps, the DCXO may have a wide tuning range with high resolution.