Abstract: An ultra-high coupling factor transformer has a plurality of conductive layers, a primary winding inductor, and a secondary winding inductor. The primary winding inductor is defined by a plurality of turns and disposed on a first one of the plurality of conductive layers and extends to a second one of the plurality of conductive layers. The secondary winding inductor is defined by a plurality of turns and disposed on the first one of the plurality of conductive layers and extends to the second one of the plurality of conductive layers. The primary winding is vertically and horizontally cross coupled with the secondary winding inductor, and defines a mutual coupling inductance from surrounding directions.

Abstract: A method includes generating a first current through a first node based on a differential pair of signals received by a differential pair of input nodes of a differential circuit of a first integrated circuit die of an isolator product. The method includes generating a second current through a second node. The second current matches the first current through the first node and is based on an attenuated version of an output measurement signal. The method includes generating the output measurement signal having a level corresponding to an average amplitude of the differential pair of signals based on the first current and the second current.

Abstract: Devices and methods related to wideband multiplexer for radio-frequency (RF) applications. In some embodiments, a method for multiplexing radio-frequency (RF) signals can include providing a common path to receive a plurality of RF signals. The method can also include processing a first RF signal through a first path such that the processed first RF signal is routed to the common path, the processing of the first RF signal including band-passing the first RF signal for a frequency band BX. The method can further include processing a second RF signal through a second path such that the processed second signal is routed to the common path, the processing of the second RF signal including band-stopping the second RF signal for the frequency band BX such that the common path includes a wideband response that includes the frequency band BX and one or more other frequency bands.

Abstract: A wireless device comprising a first antenna and second antenna, a transceiver and a radio frequency front end system electrically coupled between the transceiver and the antennas. The RF front end system includes a first module operable to provide a high band transmit signal to the first antenna, receive a first high band receive signal and a first mid band receive signal from the first antenna. The first high band receive signal has a frequency range greater than that of the first mid band receive signal. The RF front end system further includes a second module operable to provide a mid band transmit signal to the second antenna, receive a second mid band receive signal and a second high band receive signal from the second antenna. The second high band receive signal has a frequency range greater than that of the second mid band receive signal.

Abstract: A piezoelectric microelectromechanical systems microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can include a single piezoelectric film layer disposed over the top end of the substrate and defining a diaphragm structure, the single piezoelectric film layer being substantially flat with substantially zero residual stress and formed from a piezoelectric wafer. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when subjected to sound pressure via the opening in the substrate.

Abstract: Architectures and techniques relate to ganged and switch combined systems for satellite-navigation-band filters. For example, a system can include a multiplexer configured to receive an input signal from an antenna and provide an output signal, and a combined-filter circuit coupled to the multiplexer and including a mid-range-band filter and a satellite-navigation-band filter. The combined-filter circuit can be configured to receive the output signal from the multiplexer and route the output signal to the mid-range-band filter and the satellite-navigation-band filter. The mid-range-band filter and the satellite-navigation-band filter can be implemented in at least one of a ganged configuration or a switch-combined configuration.

Abstract: A method for establishing a powered link over a transmission line includes enabling a current source to provide a constant, predetermined current to a terminal. The method includes sensing a voltage on the terminal to generate a sensed voltage level. The method includes comparing the sensed voltage level on the terminal to a predetermined voltage level. The method includes disabling the current source in response to the sensed voltage level equaling or exceeding the predetermined voltage level. The method may include, while the current source is enabled, a power transistor coupled to the terminal is disabled and only conducts current in a subthreshold region of transistor operation.

Abstract: Aspects of this disclosure relate to a band pass filter that includes LC resonant circuits coupled to each other by a capacitor. A bridge capacitor can be in parallel with series capacitors, in which the series capacitors include the capacitor coupled between the LC resonant circuits. The bridge capacitor can create a transmission zero at a frequency below the passband of the band pass filter. The LC resonant circuits can each include a surface mount capacitor and a conductive trace of the substrate, and an integrated passive device die can include the capacitor. Band pass filters disclosed herein can be relatively compact, provide relatively good out-of-band rejection, and relatively low loss.

Abstract: Noise-cancellation techniques based on differential filtering, and front-end modules and wireless devices incorporating same. An example of a front-end module includes a transmit contact, a receive contact, and an antenna contact, a duplexer including a transmit filter connected in a transmit path between the transmit and antenna contacts, and a receive filter connected in a receive path between the antenna and receive contacts, the transmit filter having an input and the receive filter having an output, differential signal lines connected to one of the input of the transmit filter or the output of the receive filter, and configured to provide a differential transmit signal to the input of the transmit filter or provide a differential receive signal from the output of the receive filter, and a bandpass filter connected between the differential signal lines and configured to provide a frequency-specific short between the differential signal lines.

Abstract: A method of fabricating an electronics package includes forming a cavity in a first surface of a semiconductor substrate, forming one or more passive devices on the semiconductor substrate, forming a microelectromechanical device on a piezoelectric substrate, and bonding the semiconductor substrate to the piezoelectric substrate with the microelectromechanical device disposed within the cavity.

Abstract: Examples provide methods and apparatus for controlling a DC bias current in an RF amplifier. In one example where the RF amplifier is implemented on an amplifier die, a reference voltage is produced across a reference resistor implemented on the amplifier die, the DC bias current is measured, and a current controller, which is implemented on a controller die that is separate from the amplifier die, operates a feedback loop using the reference voltage to control a level of the DC bias current.

Abstract: Circuits and devices related to switch controller. In some embodiments, a radio-frequency module can include a packaging substrate configured to receive a plurality of components, and a switching circuit implemented on the packaging substrate. The radio-frequency module can further include a control circuit configured to control operation of the switching circuit. The control circuit can include a regulator configured to generate a plurality of reference voltage levels for the operation of the switching circuit, or to be in a sleep mode, based on a control signal received through a common input node. The control circuit can further include a mode detector in communication with the regulator and configured to provide a first form of the control signal to the common input node to allow the plurality of reference levels to be generated by the regulator, or a second form of the control signal to the common input node to put the regulator in the sleep mode.

Abstract: Described herein are variable gain amplifiers and multiplexers that embed programmable attenuators into switchable paths to provide variable gain for individual amplifier inputs. The variable gain for an individual input is provided using an amplification stage that is common for each input of the amplifier. A variable attenuation is provided for individual inputs through a combination of a band selection switch and an attenuation selection branch. Individual inputs can be configured to bypass the variable attenuation in a high gain mode.

Abstract: Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

Abstract: Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.

Abstract: Front-end for processing 2G signal using 3G/4G paths. In some embodiments, a front-end architecture can include a first amplification path and a second amplification path, with each being configured to amplify a 3G/4G signal, and the first amplification path including a phase shifting circuit. The front-end architecture can further include a splitter configured to receive a 2G signal and split the 2G signal into the first and second amplification paths, and a combiner configured to combine amplified 2G signals from the first and second amplification paths into a common output path. The front-end architecture can further include an impedance transformer implemented along the common output path to provide a desired impedance for the combined 2G signal.

Abstract: Apparatus and methods for beamforming communication systems with power control based on antenna pattern configuration are provided. In certain embodiments, a beamforming communication system includes an antenna array including a plurality of antenna elements. The beamforming communication system further includes a plurality of signal conditioning circuits operatively associated with the antenna elements, and an antenna array management circuit that generates a plurality of control signals that individually control the signal conditioning circuits. The antenna array management circuit achieves a desired level of power control based on generating the control signals to select an antenna pattern configuration associated with a desired power control level.

Abstract: A method for modelling a power amplifier, including memory effect modelling, for general input waveforms and power levels involves generating an extraction waveform having a plurality of tones each having a different frequency, a difference between the frequencies of two adjacent tones of the plurality of tones not being an integer multiple of a difference in frequency between any two other adjacent tones of the plurality of tones. The method further involves providing the extraction waveform to the power amplifier, receiving output from the power amplifier generated in response to the extraction waveform, and generating a model of the power amplifier based on the output.

Abstract: Low noise serial interfaces with gated clock are provided herein. In certain configurations herein, a slave device of a serial interface includes a shift register for serially shifting in an interface data signal based on timing of an interface clock signal, a control circuit (for instance, a finite-state machine) for controlling the slave device, and a register bank for storing data programmed to the slave device via the serial interface. The control circuit cuts off or gates the interface clock signal in response to determining that an interface command received over the serial interface is not intended for the slave device.

Abstract: Cascode power amplifier bias circuits suitable for operating across multiple power supply domains are provided. In certain embodiments, a power amplifier system includes a cascode power amplifier and a multi-domain bias circuit that generates at least a first cascode bias voltage for the cascode power amplifier. The multi-domain bias circuit includes a coarse regulator that generates a regulated voltage based on a power supply voltage that is operable with multiple voltage levels associated with different power supply domains, a bandgap reference circuit that is powered by the regulated voltage and outputs a bandgap reference voltage, a bias voltage generator that generates multiple selectable bias voltages based on the bandgap reference voltage, and a bias voltage selector that chooses the first cascode bias voltage from amongst the selectable bias voltages.