Abstract: Circuits, devices and methods related to impedance tuners. In some embodiments, a capless impedance tuner can include first node and second nodes, a first series path, a second series path, and an inductance path, each between the first node and the second node and including a switch to allow the path to couple or uncouple the first and second nodes. Each series path can be configured to allow a substantially continuous flow of a direct current between the first node and the second node when coupled. The tuner can further include a shunt path with a switch to allow coupling or uncoupling of the second node and ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

Abstract: In one example, a remote tuner module includes: a first tuner to receive, process and demodulate a first radio frequency (RF) signal to output an analog audio signal, and to receive and process a second RF signal to output a first downconverted modulated signal; a second tuner to receive and process the second RF signal to output a second downconverted modulated signal; a demodulator circuit coupled to the first and second tuners to demodulate and link the first and second modulated signals, to output a linked demodulated signal. The remote tuner module may further include a gateway circuit coupled to at least the demodulator circuit to output the analog audio signal and the linked demodulated signal.

Abstract: A piezoelectric microelectromechanical system microphone comprises a frame, a film of piezoelectric material including slits defining a plurality of independently displaceable piezoelectric elements within an area defined by a perimeter of the frame, bases of the plurality of piezoelectric elements mechanically secured to the frame, tips of the plurality of piezoelectric elements being free to be displaced in a direction perpendicular to a plane defined by the frame responsive to impingement of sound waves on the plurality of piezoelectric elements, and edge extensions extending from edges of the plurality of piezoelectric elements in the direction perpendicular to the plane defined by the frame to reduce a 3 dB roll-off frequency of the piezoelectric microelectromechanical system microphone.

Abstract: A fuse circuit that permits a fuse to be selected and programmed using a single fuse pad. The fuse circuit includes a fuse pad to receive a first voltage, a fuse coupled in series with a voltage controlled switch between the fuse pad and a reference node, and a switch control circuit coupled in series between the fuse pad and the reference node and in parallel with the fuse and the voltage controlled switch, the switch control circuit being configured to select and program the fuse responsive to the first voltage received at the fuse pad. The fuse pad may subsequently be grounded and a sense circuit may be coupled to the fuse to measure a voltage dropped across the fuse to determine whether the fuse has been programmed.

Abstract: A controller enumerates a plurality of devices while operating in a daisy-chain mode of operation and then causes the devices to operate in a parallel mode of operation in which the devices are individually addressed.

Abstract: Radio frequency front end modules are provided. In one aspect, a front end system includes at least one power amplifier configured to amplify a transmit radio frequency signal, at least one low noise amplifier configured to receive a receive radio frequency signal, an output node coupled to an antenna. The front end system further includes at least one switch configured to selectively couple the output node to the at least one power amplifier during a transmit period and to the at least one low noise amplifier during a receive period, at least one transmit filter coupled between the power amplifier and the at least one switch, and at least one receive filter coupled between the low noise amplifier and the at least one switch.

Abstract: Multi-level envelope trackers with an analog interface are provided herein. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, and an MLS modulator that controls selection of the regulated voltages over time based on an analog envelope signal corresponding to an envelope of the RF signal amplified by the power amplifier.

Abstract: Aspects of this disclosure relate to a front end architecture for selectively adding an external carrier aggregation band. A switch element can connect a radio frequency signal path to an antenna path through a frequency domain multiplexer, such as a diplexer, in a first mode. The switch element can connect the radio frequency path to the antenna path and bypass the frequency domain multiplexer in a second mode. The frequency domain multiplexer can be external to a front end module that include the radio frequency signal path. In the first mode, a front end system can support carrier aggregation with a band associated with circuitry implemented external to the front end module.

Abstract: Devices and methods for switch body connections to achieve soft breakdown. In some embodiments, a method of implementing a radio-frequency switching device can include providing an assembly of source, gate, and drain implemented on an active region; providing a first body contact implemented at a first end of the assembly; and providing a second body contact implemented at a second end of the assembly, the second end distal from the first end along a width of the radio-frequency switching device.

Abstract: Aspects of this disclosure relate to a surface acoustic wave filter with an integrated temperature sensor. The integrated temperature sensor can be a resistive thermal device configured as a reflective grating for a surface acoustic wave resonator, for example. A radio frequency system can provide over temperature protection by reducing a power level of a radio frequency signal provided to the surface acoustic wave filter responsive to an indication of temperature provided by the integrated temperature sensor satisfying a threshold.

Abstract: Reconfigurable antenna systems with ground tuning pads are provided herein. In certain configurations, an antenna system includes an antenna element, a first tuning conductor spaced apart from the antenna element on a first side of the antenna element, a second tuning conductor spaced apart from the antenna element on a second side of the antenna element, a first ground tuning pad configured to receive a ground voltage, and a first switch electrically connected between the first tuning conductor and the first ground tuning pad. The first switch is operable to selectively connect the first tuning conductor to the first ground tuning pad to thereby tune the antenna element.

Abstract: Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker supplies power to a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit that generates an output current based on an envelope signal indicating an envelope of the RF signal. The envelope tracker further includes a combiner that combines a DC voltage with the output current of the multi-level switching circuit to generate a power amplifier supply voltage for the power amplifier. Accordingly, the output current of the multi-level switching circuit and a DC voltage are combined to generate the power amplifier supply voltage. Implementing the envelope tracking system in this manner can provide enhanced efficiency and/or higher bandwidth relative to an envelope tracking system in which a multi-level switching circuit directly outputs a power amplifier supply voltage.

Abstract: A flip-chip semiconductor-on-insulator die includes a substrate layer, an active layer, an insulator layer between the substrate layer and the active layer, a first metal layer, and a first via layer between the active layer and the first metal layer. The die at least first and second contact pads and a transistor including a first terminal formed within the active layer. A first portion of the first terminal falls within a footprint of the first contact pad and a second portion of the first terminal falls within a footprint of the second contact pad.

Abstract: Beamforming communication systems with modular front-ends are provided herein. In certain embodiments, a beamforming communication system includes an antenna array partitioned into a plurality of sub-arrays, and a plurality of front-end modules each operatively associated with one of the sub-arrays. Each of the front-end modules includes at least two radio frequency (RF) transmit channels and at least two RF receive channels. Thus, the signals transmitted and received on the antenna array are processed using a multiple front-end modules servicing sub-arrays.

Abstract: Apparatus and methods for true power detection are provided herein. In certain embodiments, a power amplifier system includes an antenna, a directional coupler, and a power amplifier electrically connected to the antenna by way of a through line of the directional coupler. The power amplifier system further includes a first switch, a second switch, and a combiner that combines a first coupled signal received from a first end of the directional coupler's coupled line through the first switch and a second coupled signal received from a second end of the directional coupler's coupled line through the second switch.

Abstract: A delay circuit provides a programmable delay and includes an input selector circuit to select between a loop delay output signal and an input signal. A loop delay circuit provides a loop delay to the input signal and supplies the loop delay output signal. The input signal can be recirculated through the loop delay circuit to extend the range of the delay. The input selector circuit selects the feedback signal during recirculation. A variable delay circuit provides a variable delay to the loop delay output signal after the recirculation is complete and supplies a variable delay output signal. An output selector circuit selects the output of the output selector circuit during the recirculation and selects the variable delay output signal after the recirculation is complete to thereby provide a delayed signal with the delay based on the loop delay, the number of loops of recirculation, and the variable delay.

Abstract: A packaging substrate can include a first surface and a second opposing surface, the first surface including a first mounting region of a first electronic module region and the second opposing surface including a first electrical contacts region of the first electronic module region. The packaging substrate can include a saw street region with at least a portion that surrounds the first electronic module region, and a saw street feature formed on the second opposing surface within at least a portion of the saw street region, the saw street feature being a solder mask layer over a metal layer.

Abstract: A diversity receiver module comprising a multiple pole multiple throw switch, one throw being connected to a signal path configured to support both ultra-high band transmit signals and high-band transmit signals, and another throw being connected to an ultra-high band signal path configured to output an ultra-high band receive signal; an ultra-high band filter configured to filter ultra-high band signals, the ultra-high band filter being connected to a pole of the switch via a signal path; a high band filter configured to filter high band receive signals, the high band filter being diplexed with the ultra-high band filter; and a high band signal path configured to output a high-band receive signal, the high band signal path being connected to the high band filter.

Abstract: Charging and discharging circuits for assisting charge pumps are disclosed. In certain embodiments, a radio frequency (RF) switch system includes an RF switch that receives an RF signal and is controlled by a switch control signal received at an input, a first charge pump configured to generate a first charge pump voltage, a level shifter powered by the first charge pump voltage and that generates the switch control signal based on a switch enable signal, and a charge pump assistance switch coupled to the input of the radio frequency switch and that activates to assist the first charge pump in response to a transition of the switch enable signal from a first state to a second state.

Abstract: A printed circuit board can include a substrate layer, a first metal layer disposed over the substrate layer, a core layer disposed over the first metal layer, and a second metal layer disposed over the core layer, where the core layer defines a closed cavity between the first and second metal layers. Optionally, the cavity is filled with air and operates as an antenna.