Abstract: A method for fabricating a semiconductor device involves providing a transistor device, forming one or more electrical connections to the transistor device, forming one or more dielectric layers over at least a portion of the electrical connections, applying an interface material over at least a portion of the one or more dielectric layers, removing at least a portion of the interface material to form a trench, and covering at least a portion of the interface material and the trench with a substrate layer to form a cavity.

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

Abstract: A radio-frequency switch includes a first field-effect transistor having drain and source fingers separated by a first drain-to-source distance and a second field-effect transistor in a series connection with the first field-effect transistor, the second field-effect transistor having drain and source fingers separated by a second drain-to-source distance that is different than the first drain-to-source distance.

Abstract: Stack device having voltage compensation. In some embodiments, a switching device can include switching elements connected in series between a first terminal and a second terminal, with a first end switching element being connected to the first terminal and a second end switching element being connected to the second terminal. Each switching element can have a parameter such that the switching elements have a distribution of parameter values that decreases from the first end switching element for at least half of the switching elements to a minimum parameter value corresponding to a switching element between the first end switching element and the second end switching element. The minimum parameter value can be less than the parameter value of the second end switching element, and the parameter value of the first end switching element can be greater than or equal to the parameter value of the second end switching element.

Abstract: A transistor device includes a plurality of drain fingers that are elongate in a first dimension, a plurality of source fingers that are elongate in the first dimension and interleaved with the plurality of drain fingers, one or more drain contact bars extending over a first set of the plurality of drain fingers and a first set of the plurality of source fingers in a second dimension that is orthogonal to the first dimension, and one or more source contact bars extending over a second set of the plurality of drain fingers and a second set of the plurality of source fingers in the second dimension.

Abstract: Fabricating of radio-frequency (RF) devices involves providing a field-effect transistor formed over an oxide layer formed on a semiconductor substrate and converting at least a portion of the semiconductor substrate to porous silicon.

Abstract: A radio-frequency (RF) device includes a semiconductor substrate, a first field-effect transistor (FET) disposed on the substrate, the first FET having a first plurality of drain fingers, and a second FET connected in series with the first FET along a first dimension, the second FET having a second plurality of drain fingers that extent in a second dimension that is orthogonal with respect to the first dimension.

Abstract: MEMS devices having discharge circuits. In some embodiments, a MEMS device can include a substrate and an electromechanical assembly implemented on the substrate. The MEMS device can further include a discharge circuit implemented relative to the electromechanical assembly. The discharge circuit can be configured to provide a preferred arcing path during a discharge condition affecting the electromechanical assembly. The MEMS device can be, for example, a switching device, a capacitance device, a gyroscope sensor device, an accelerometer device, a surface acoustic wave (SAW) device, or a bulk acoustic wave (BAW) device. The discharge circuit can include a spark gap assembly having one or more spark gap elements configured to facilitate the preferred arcing path.

Abstract: A method for fabricating a transistor device involves providing a substrate, forming an oxide layer over at least a portion of the substrate, forming a transistor over at least a portion of the oxide layer, and removing at least a portion of a backside of the substrate to form an opening providing radio-frequency isolation for the transistor.

Abstract: A power amplifier can include a carrier amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a carrier transformer, and a peaking amplifier having first and second differential amplification cells with outputs coupled by a primary loop of a peaking transformer. The power amplifier can further include a combiner having a quarter-wave circuit implemented between the secondary loop of the carrier transformer and a secondary loop of the peaking transformer. The quarter-wave circuit can be configured to provide a characteristic impedance, such that the carrier and peaking amplifiers are presented with an impedance that is approximately the same as the characteristic impedance when both of the carrier and peaking amplifiers are turned on, and the carrier amplifier is presented with an impedance that is approximately twice the characteristic impedance when the carrier amplifier is turned on and the peaking amplifier is turned off.

Abstract: A component of an electronic device comprises a semiconductor die flip-chip mounted on a printed circuit board and a barrier mechanically coupled to a portion of the die and the printed circuit board, the barrier defining a cavity between a surface of the die and the printed circuit board.

Abstract: Radio-frequency (RF) devices are fabricated by providing a field-effect transistor (FET) formed over a an oxide layer formed on a substrate layer and removing at least a portion of the substrate layer to form an opening exposing at least a portion of a backside of the oxide layer, the opening being positioned to enhance RF performance for one or more components of the RF device.

Abstract: Disclosed herein are power amplification (PA) systems configured to amplify a signal, such as a radio-frequency signal. The PA system includes a plurality of power amplifiers that are configured to amplify a signal received at a signal input and to output the amplified signal at a signal output. The power amplifiers are configured to receive a supply voltage that is a combination of a battery voltage and an envelope tracking signal. The PA system includes a PA controller configured to control the power amplifiers based at least in part on the battery voltage or a power output of the power amplifiers. The PA controller can be configured to alter impedance matching components of the PA system to reconfigure a load line of the power amplifiers.

Abstract: Systems, methods, and devices for communicating with a serial/parallel interface are described herein. In an aspect, a wireless device includes a transceiver configured to output a plurality of transmission paths, and an antenna configured to output a signal corresponding to at least one of the transmission paths. The wireless device further includes a wireless switching component including a radio-frequency switch configured to selectively connect the antenna to one of the transmission paths, a plurality of signal pins, a serial interface including a plurality of serial inputs electrically coupled to at least one pin of the plurality of signal pins, a parallel interface including a plurality of parallel inputs electrically coupled to at least one pin of the plurality of signal pins, a decoder, and a level shifter configured to control the radio-frequency switch, the at least one pin electrically coupled to both a serial input and a parallel input.

Abstract: Disclosed are systems, circuits and methods related to low-loss bypass of a radio-frequency (RF) filter or diplexer. In some embodiments, a switching network circuitry can include a first switch that has an input pole configured to receive a radio-frequency (RF) signal, a pass-through throw configured to be connectable to the input pole to allow routing of the RF signal to an RF component, and at least one dedicated bypass throw configured to be connectable to the input pole and at least one bypass conduction path. The switching network circuitry can further include a second switch that has a pole and a throw, and is connectable between an output of the RF component and the bypass conduction path. Use of the dedicated bypass throw(s) in the first switch allows implementation of low-loss bypass of the filter or diplexer.

Abstract: Integrated filter and electromagnetic coupler assemblies. In certain examples, an integrated filter and electromagnetic coupler assembly includes a filter having a capacitance and a series inductance, the series inductance being connected between an input port and an output port of the integrated filter and electromagnetic coupler assembly, and combination of the capacitance and the series inductance being selected to provide the filter with a passband and a stopband. The integrated filter and electromagnetic coupler assembly further includes a coupling element positioned physically proximate the series inductance and extending between a coupled port and an isolation port of the integrated filter and electromagnetic coupler assembly, the integrated filter and electromagnetic coupler assembly being configured to provide at the coupled port a coupled signal via inductive coupling between the series inductance and the coupling element responsive to receiving an input signal at the input port.

Abstract: Provided herein are apparatus and methods for reconfigurable directional couplers in an RF transceiver. Reconfigurable directional couplers can be reconfigured and designed to provide high directivity using configurable capacitors to effect a mutual coupling and using lumped components or delay lines to effect a phase shift. Depending on the embodiment, the reconfigurable directional coupler can include capacitors, inductors, and switching components. The coupler can be designed for multi-band operation with an adjustable coupling factor conducive to semiconductor process integration. The coupler can have variable phase shifters to achieve a desired level of directivity in the coupler.

Abstract: A filtered electromagnetic coupler includes a main transmission line extending between an input port and an output port, and a coupled line section extending between a coupled port and an isolation port. The coupler is configured to couple signal power from the main transmission line to provide coupled signals at the coupled port, and a filter subsystem is connected to the coupled port to filter the coupled signals. The filter subsystem includes filters configured to pass or reject coupled signals by frequency, and the filter subsystem provides the filtered output signal to a measurement node.

Abstract: An electromagnetic coupler assembly includes a handle wafer having an oxide layer disposed on a first surface thereof. A layer of active semiconductor is disposed on the oxide layer and includes a voltage terminal to receive a supply voltage. A layer of dielectric material is disposed on the layer of active semiconductor. A main transmission line is disposed on the layer of dielectric material. A coupled transmission line is disposed on the layer of active semiconductor and is one of inductively coupled to the main transmission line and capacitively coupled to the main transmission line. At least a portion of one of the main transmission line and the coupled transmission line is disposed directly above at least a portion of the layer of active semiconductor.

Abstract: A semiconductor device includes a transistor device implemented over an oxide layer, an interface layer applied below at least a portion of the oxide layer, the interface layer having a trench formed therein, and a substrate layer covering at least a portion of the interface layer and the trench to form a cavity.