Abstract: Segmented power amplifier (PA) arrangements are disclosed. An example PA arrangement includes at least first and second PA segments, each having a respective combination of a PA and a feedforward adaptive bias circuit, configured to generate a bias signal for the corresponding PA. Each bias signal has a first DC component, at least one tone component, and at least one harmonic of the at least one tone component. The PA arrangement further includes a power splitting circuit, configured to split an input signal for the PA arrangement into a first PA input signal for the first PA segment and a second PA input signal for the second PA segment, where a power of the first PA input signal is greater than a power of the second PA input signal.

Abstract: Systems and methods for use in aiding an inertial navigation system during a GNSS signal outage. An ultrasonic transceiver is positioned adjacent a wheel of a vehicle and reflections of the emitted signal are used to determine changes of direction and/or to determine a distance traveled by the vehicle. For changes of direction, the transceiver is adjacent to a front wheel such that left or right turns cause the wheel to interrupt a signal path from the transceiver to a reflector. For distance estimates, the transceiver is adjacent a back wheel of the vehicle. The ultrasonic signal is reflected off of solid sections of the wheel or passes through void sections of the wheel. The measurements obtained can be processed in various ways to estimate number of rotations of the wheel and, accordingly, the distance traveled by the vehicle.

Abstract: Systems, methods, and apparatuses for improving reliability and/or reducing the likelihood of breakdown of an amplifier or a component thereof. A system can include a sensing circuit electrically coupled to a transistor of the amplifier and configured to sense an AC voltage associated with the transistor. A protection circuit can be electrically coupled to the sensing circuit and the amplifier and can be configured to supply a DC voltage to the transistor of the amplifier based on the AC voltage sensed by the sensing circuit.

Abstract: Bias arrangements for amplifiers are disclosed. An example arrangement includes a bias circuit, configured to produce a bias signal for the amplifier, and a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal based on an RF signal indicative of an RF input signal to be amplified by the amplifier. The linearization circuit includes a bias signal input for receiving the bias signal, an RF signal input for receiving the RF signal, and an output for providing a modified bias signal. The linearization circuit further includes at least a first linearization transistor, having a first terminal, a second terminal, and a third terminal, where each of the bias signal input and the RF signal input of the linearization circuit is coupled to the first terminal of the first linearization transistor, and the output of the linearization circuit is coupled to the third terminal of the first linearization transistor.

Abstract: Segmented power amplifier (PA) arrangements are disclosed. An example PA arrangement includes at least first and second PA segments, each having a respective combination of a PA and a feedforward adaptive bias circuit, configured to generate a bias signal for the corresponding PA. Each bias signal has a first DC component, at least one tone component, and at least one harmonic of the at least one tone component. The PA arrangement further includes a power splitting circuit, configured to split an input signal for the PA arrangement into a first PA input signal for the first PA segment and a second PA input signal for the second PA segment, where a power of the first PA input signal is greater than a power of the second PA input signal.

Abstract: Bias arrangements for amplifiers are disclosed. An example bias arrangement for an amplifier includes a bias circuit, configured to produce a bias signal for the amplifier; a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal produced by the bias circuit to produce a modified bias signal to be provided to the amplifier; and a coupling circuit, configured to couple the bias circuit and the linearization circuit. Providing separate bias and linearization circuits coupled to one another by a coupling circuit allows separating a linearization operation from a biasing loop to overcome some drawbacks of prior art bias arrangements that utilize a single biasing loop.

Abstract: Bias arrangements for amplifiers are disclosed. An example arrangement includes a bias circuit, configured to produce a bias signal for the amplifier, and a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal based on an RF signal indicative of an RF input signal to be amplified by the amplifier. The linearization circuit includes a bias signal input for receiving the bias signal, an RF signal input for receiving the RF signal, and an output for providing a modified bias signal. The linearization circuit further includes at least a first linearization transistor, having a first terminal, a second terminal, and a third terminal, where each of the bias signal input and the RF signal input of the linearization circuit is coupled to the first terminal of the first linearization transistor, and the output of the linearization circuit is coupled to the third terminal of the first linearization transistor.

Abstract: Bias arrangements for amplifiers are disclosed. An example bias arrangement for an amplifier includes a bias circuit, configured to produce a bias signal for the amplifier; a linearization circuit, configured to improve linearity of the amplifier by modifying the bias signal produced by the bias circuit to produce a modified bias signal to be provided to the amplifier; and a coupling circuit, configured to couple the bias circuit and the linearization circuit. Providing separate bias and linearization circuits coupled to one another by a coupling circuit allows separating a linearization operation from a biasing loop to overcome some drawbacks of prior art bias arrangements that utilize a single biasing loop.

Abstract: Systems, methods, and apparatuses for improving reliability and/or reducing the likelihood of breakdown of an amplifier or a component thereof. A system can include a sensing circuit electrically coupled to a transistor of the amplifier and configured to sense an AC voltage associated with the transistor. A protection circuit can be electrically coupled to the sensing circuit and the amplifier and can be configured to supply a DC voltage to the transistor of the amplifier based on the AC voltage sensed by the sensing circuit.

Abstract: Systems, methods, and apparatuses for improving reliability and/or reducing or preventing breakdown of an amplifier, specifically breakdown of a transistor of an amplifier, are disclosed. A protection circuit can be electrically coupled to the amplifier, and can be configured to reduce a voltage swing at the amplifier. The amplifier can include a first transistor, and the protection circuit can include a second transistor electrically coupled to a control terminal of the first transistor of the amplifier. When a power at a control terminal of the second transistor of the protection circuit satisfies a threshold power, the protection circuit can be configured to reduce a power at a power terminal of the first transistor the amplifier. By reducing the voltage at the power terminal of the first transistor the amplifier, the protection circuit can allow the amplifier to operate safely, without breakdown.

Abstract: Systems and methods for use in aiding an inertial navigation system during a GNSS signal outage. An ultrasonic transceiver is positioned adjacent a wheel of a vehicle and reflections of the emitted signal are used to determine changes of direction and/or to determine a distance traveled by the vehicle. For changes of direction, the transceiver is adjacent to a front wheel such that left or right turns cause the wheel to interrupt a signal path from the transceiver to a reflector. For distance estimates, the transceiver is adjacent a back wheel of the vehicle. The ultrasonic signal is reflected off of solid sections of the wheel or passes through void sections of the wheel. The measurements obtained can be processed in various ways to estimate number of rotations of the wheel and, accordingly, the distance traveled by the vehicle.

Abstract: Aspects of this disclosure relate to an adaptive biasing circuit for a power amplifier. The adaptive biasing circuit can include a shunt resistor arrangement and/or a floating gate linearizer arrangement.

Abstract: Systems, methods, and apparatuses for improving reliability and/or reducing or preventing breakdown of an amplifier, specifically breakdown of a transistor of an amplifier, are disclosed. A protection circuit can be electrically coupled to the amplifier, and can be configured to reduce a voltage swing at the amplifier. The amplifier can include a first transistor, and the protection circuit can include a second transistor electrically coupled to a control terminal of the first transistor of the amplifier. When a power at a control terminal of the second transistor of the protection circuit satisfies a threshold power, the protection circuit can be configured to reduce a power at a power terminal of the first transistor the amplifier. By reducing the voltage at the power terminal of the first transistor the amplifier, the protection circuit can allow the amplifier to operate safely, without breakdown.

Abstract: Aspects of this disclosure relate to an adaptive biasing circuit for a power amplifier. The adaptive biasing circuit can include a shunt resistor arrangement and/or a floating gate linearizer arrangement.

Abstract: The present disclosure provides a voltage variable attenuator (VVA) with a controllable matching network. The output of the attenuation portion of the VVA is couple to a matching network. The matching network includes a resistive element, which may be a Field Effect Transistor (FET), whose resistance may be controlled as a function of attenuation. In particular, a control voltage used to control the resistance of the attenuation portion of the VVA is also used to control the resistive element of the matching network. In this manner, the output impedance of the VVA may be maintained at a desired level.

Abstract: The present disclosure provides a voltage variable attenuator (VVA) with a controllable matching network. The output of the attenuation portion of the VVA is couple to a matching network. The matching network includes a resistive element, which may be a Field Effect Transistor (FET), whose resistance may be controlled as a function of attenuation. In particular, a control voltage used to control the resistance of the attenuation portion of the VVA is also used to control the resistive element of the matching network. In this manner, the output impedance of the VVA may be maintained at a desired level.

Abstract: Mixers with improved linearity are disclosed. A diode or FET ring mixer is implemented with at least one parallel shunt element coupled with the ring mixer, the shunt element providing shunt to a diode or FET, for example, to reduce the effect of nonlinear or off resistance and/or capacitance. Linearity, isolation, symmetry, even order harmonics of the ring mixer, or any combination thereof can be improved as a result. The linearity of the ring mixer with parallel shunt resistors can be further improved by adding series resistors in the ring according to certain embodiments.

Abstract: Mixers with improved linearity are disclosed. A diode or FET ring mixer is implemented with at least one parallel shunt element coupled with the ring mixer, the shunt element providing shunt to a diode or FET, for example, to reduce the effect of nonlinear or off resistance and/or capacitance. Linearity, isolation, symmetry, even order harmonics of the ring mixer, or any combination thereof can be improved as a result. The linearity of the ring mixer with parallel shunt resistors can be further improved by adding series resistors in the ring according to certain embodiments.

Abstract: A three-axis load sensor utilizing four piezoresistive devices on a flexible silicon membrane is provided. The load sensor further includes a mesa disposed on the membrane substantially equidistant from the piezoresistive devices. A six-axis load cell is provided by placing a plurality of load sensors disposed on a substrate, the substrate configured to attach to an object wherein forces applied to the object can be measured and/or determined. The load sensors can be manufactured using bulk microfabrication techniques on a single crystal silicon wafer, and can detect normal and shear loading applied to the membrane.

Abstract: An apparatus and method is provided for characterizing adhesive bonding using an acoustic wave MEMS sensor. The sensor can consist of a silicon substrate, a thin aluminum nitride film on top of the substrate and a thin gold film above the aluminum nitride layer. An adhesive layer is added on top of the sensor and the dispersion property of acoustic waves in the layered configuration can be utilized for bonding integrity characterization. A wave dispersion model is developed to study the effect of changing the interface stiffness on the wave dispersion profile and to investigate the sensitivity of different sensor configurations. The results of the model illustrate that the dispersion profile shifts in the direction of decreasing wave velocity as the interface stiffness decreases.