Abstract: Diversity modules for processing radio frequency (RF) signals are provided herein. In certain implementations a diversity module includes a first terminal, a second terminal, a low band processing circuit that generates a low band signal based on one or more diversity signals, a mid band processing circuit that generates a mid band signal based on the one or more diversity signals and that provides the mid band signal to the second terminal, a high band processing circuit that generates a high band signal based on the one or more diversity signals, and a multi-throw switch that provides the low band signal to the first terminal in a first state and that provides the high band signal to the first terminal in a second state.

Abstract: Devices and method for bypassing voltage regulation in voltage regulators. A voltage regulator may include a duty cycle component configured to determine whether a duty cycle of the voltage regulator is greater than a threshold duty cycle. The voltage regulator may also include a first sensing component configured to determine whether an output voltage of the voltage regulator is less than a first threshold voltage. The voltage regulator may further include a regulating component, coupled to the duty cycle component and the first sensing component, the regulating component configured to pass an input voltage to the output of the voltage regulator based on a first determination that the duty cycle is greater than the threshold duty cycle and a second determination that the output voltage of the voltage regulator is less than the first threshold voltage.

Abstract: Antenna impedance prediction via power amplifier parameter. In some embodiments, a power amplification system can include a splitter circuit and a combiner circuit, and first and second Doherty power amplifiers implemented in a quadrature configuration between the splitter circuit and the combiner circuit, with each Doherty power amplifier including a carrier amplifier and a peaking amplifier. The power amplification system can further include a monitoring circuit configured to measure at least some of base currents associated with the carrier and peaking amplifiers of the first and second Doherty power amplifiers, and generate a signal capable of adjusting a load impedance presented to an output of the combiner circuit.

Abstract: Aspects of this disclosure relate to a multiplexer, such as a duplexer, a quadplexer, a hexaplexer, or the like. The multiplexer includes acoustic wave filters coupled to a common node. A first acoustic wave filter of the acoustic wave filters includes acoustic wave resonators of a first type and a series acoustic wave resonator of a second type coupled between the acoustic wave resonators of the first type and the common node.

Abstract: Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material, such as Y-phase hexagonal ferrite material, and methods of manufacturing. In some embodiments, sodium or potassium can be added into the crystal structure of the hexagonal ferrite material in order to achieve improved resonant frequencies in the range of 500 MHz to 1 GHz useful for radiofrequency applications.

Abstract: The fabrication of field-effect transistor (FET) devices is described herein where the FET devices include one or more body contacts implemented between source, gate, drain (S/G/D) assemblies to improve the influence of a voltage applied at the body contact on the S/G/D assemblies. The FET devices can include source fingers and drain fingers interleaved with gate fingers. The source and drain fingers of a first S/G/D assembly can be electrically connected to the source and drain fingers of a second S/G/D assembly.

Abstract: Methods and systems are provided for generating an oscillating signal for use as a clock in digital logic timing. The oscillating signal is generated via a differential RC relaxation oscillator including an oscillator core and biasing circuitry. The oscillator core may be configured such that the oscillating signal it generates is substantially sinusoidal or pseudo-sinusoidal and contains less harmonic content relative to a square wave signal. The biasing circuitry may be configured to have a reduced dependence on temperature so that the biasing values it provides vary less with temperature.

Abstract: Disclosed herein are embodiments of composite hexagonal ferrite materials formed from a combination of Y phase and Z phase hexagonal ferrite materials. Advantageously, embodiments of the material can have a high resonant frequency as well as a high permeability. In some embodiments, the materials can be useful for magnetodielectric antennas.

Abstract: A semiconductor device includes a transistor implemented over an oxide layer, one or more electrical connections to the transistor, one or more dielectric layers formed over at least a portion of the electrical connections, an electrical element disposed over the one or more dielectric layers, the electrical element being in electrical communication with the transistor via the one or more electrical connections, a patterned form of sacrificial material covering at least a portion of the electrical element, and an interface layer covering at least a portion of the one or more dielectric layers and the sacrificial material.

Abstract: A method for fabricating a semiconductor device involves providing a transistor device formed over an oxide layer formed on a semiconductor substrate, removing at least part of the semiconductor substrate, applying an interface material below to at least a portion of the oxide layer, removing a portion of the interface material to form a trench, and at least partially covering the interface material and the trench with a substrate layer to form a cavity.

Abstract: A signal switch includes a first transistor coupled between first and second nodes, a plurality of second transistors coupled in series between the first and second nodes and in parallel with the first transistor, and a first shunt path including a first shunt transistor and a first inductor connected in series between a reference node and a first connection point between two of the plurality of second transistors.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Abstract: Disclosed herein are methods for amplifying a signals. The methods include receiving signals at a plurality of input nodes. The methods also include configuring a gain stage to be in a selected one of a plurality of gain settings, at least some of the gain settings resulting in different impedances presented to the signal. The methods also include adjusting the resistance presented to the signal by the gain stage for the selected gain setting, the adjusted resistance being configured to provide a targeted constant value of the impedance at the input across the plurality of gain settings. The methods also include amplifying at least a portion of the received signals. Adjusting the resistance compensates for changes to the input impedance to improve return loss and mismatch over gain modes.

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 transmit, receive, and antenna contacts, and a duplexer including a first transmit filter connected in a transmit path between the transmit contact and the antenna contact, and a first receive filter connected in a receive path between the antenna contact and the receive contact, the first transmit filter having a differential input. In one example, the front-end module includes a power amplifier module connected in the transmit path and configured to supply a differential transmit output on first and second differential signal lines connected to the differential input of the first transmit filter, and a first bandpass filter connected between the first and second differential signal lines and configured to provide a first frequency-specific short between the first and second differential signal lines.

Abstract: In some embodiments, a front-end architecture can include a quadplexer configured to support uplink carrier aggregation with a first antenna. The quadplexer can include a low-band filter, a mid-band filter, a first high-band filter, and a second high-band filter, with each filter having a respective input node, and the quadplexer including a common output node associated with the first antenna. The front-end architecture can further include a triplexer configured to support uplink carrier aggregation with a second antenna. The triplexer can include a mid-band filter, a first high-band filter, and a second high-band filter, with each filter having a respective input node, and the triplexer including a common output node associated with the second antenna.

Abstract: High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

Abstract: Radio-frequency core circuitry includes a first switch arm associated with a first signal band and coupled to a common node, a second switch arm associated with a second signal band and coupled to the common node, a first shunt arm connected to a first shunt node in the first switch arm, and a first transmission line disposed in the first switch arm between the common node and the shunt node and having a length configured present an open circuit at a fundamental frequency associated with the second signal band and to present a short circuit at a harmonic of the fundamental frequency associated with the second signal band.

Abstract: A method of making a printed circuit board structure including a closed cavity is provided. The method can include the steps of forming a cavity in a core structure of a core layer, laminating each of a top surface and a bottom surface of the core structure with an adhesive layer and a metal layer to prepare a laminate structure and cover the cavity to define a closed cavity. The method also includes forming vias through the laminate structure, and patterning the metal layers in the laminate structure.

Abstract: Methods to improve front-side process uniformity by back-side metallization are disclosed. In some implementations, a metal layer is deposited on the back-side of a wafer prior to performing a plasma-based process on the front side of the wafer. Presence of the back-side metal layer reduces variations in, for example, thickness of a deposited and/or etched layer resulting from the plasma-based process.

Abstract: Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase strontium hexagonal ferrite material. In some embodiments, sodium can be added into the crystal structure of the hexagonal ferrite material in order to achieve high resonance frequencies while maintaining high permeability.