Abstract: Methods and devices for tuning a configurable amplifier of a multi-band RF front-end stage based on a setting of a band switch are described. A lookup table provided with the configurable amplifier is used to map configuration control data of the band switch to configuration control data of the configurable amplifier. The configurable amplifier can be part of a transmit path or a receive path of the multi-band RF front-end stage.

Abstract: Systems, methods and apparatus for efficient power control of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift in output power of the RF amplifier.

Abstract: Methods and apparatuses for use in tuning reactance are described. Open loop and closed loop control for tuning of reactances are also described. Tunable inductors and/or tunable capacitors may be used in filters, resonant circuits, matching networks, and phase shifters. Ability to control inductance and/or capacitance in a circuit leads to flexibility in operation of the circuit, since the circuit may be tuned to operate under a range of different operating frequencies.

Abstract: Devices and methods for tuning a tunable circuit based on a frequency of operation of the tunable circuit using a clockless frequency detector circuit are described. The clockless frequency detector uses a filter having a slope in its frequency response curve that includes a frequency range of operation of the tunable circuit. Frequency-based attenuation through the filter of an RF signal provided to the tunable circuit is used to provide an indication of the frequency of operation. The tunable circuit, including the clockless frequency detector, can be integrated within a same chip that is autonomously configurable based on the frequency of operation.

Abstract: Systems, methods and apparatus for efficient power control and/or compensation with respect to a varying supply voltage of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control and/or compensation is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift/variation in output power of the RF amplifier.

Abstract: Systems, methods and apparatus for efficient power control of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift in output power of the RF amplifier.

Abstract: A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

Abstract: Systems, methods and apparatus for efficient power control of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift in output power of the RF amplifier.

Abstract: Methods and apparatuses for use in tuning reactance are described. Open loop and closed loop control for tuning of reactances are also described. Tunable inductors and/or tunable capacitors may be used in filters, resonant circuits, matching networks, and phase shifters. Ability to control inductance and/or capacitance in a circuit leads to flexibility in operation of the circuit, since the circuit may be tuned to operate under a range of different operating frequencies.

Abstract: Bias circuits and methods for silicon-based amplifier architectures that are tolerant of supply and bias voltage variations, bias current variations, and transistor stack height, and compensate for poor output resistance characteristics. Embodiments include power amplifiers and low-noise amplifiers that utilize a cascode reference circuit to bias the final stages of a cascode amplifier under the control of a closed loop bias control circuit. The closed loop bias control circuit ensures that the current in the cascode reference circuit is approximately equal to a selected multiple of a known current value by adjusting the gate bias voltage to the final stage of the cascode amplifier. The final current through the cascode amplifier is a multiple of the current in the cascode reference circuit, based on a device scaling factor representing the relative sizes of the transistor devices in the cascode amplifier and in the cascode reference circuit.

Abstract: Systems, methods and apparatus for efficient control and biasing of pass devices that include at least one thin pass device and a remaining of thick pass devices. When operated at extreme high and low voltages, the at least one thin pass device maintains operation in its saturation region of operation while the remaining pass devices may be driven into their triode regions of operation. The thin and thick pass devices are arranged in a cascode configuration that includes a plurality of stacked devices. Biasing of the thin and thick cascode devices can be according to a voltage division scheme which protects the devices when the voltage across the stack is high, and provides a skewed voltage division across the stacked devices that promotes a higher gate-to-source voltage of the thick pass devices for a lower RON. In one exemplary case, gate length of the at least one thin pass device may be reduced to provide a lower gate-to-source voltage of the thin pass device during operation in the saturation region.

Abstract: Systems, methods and apparatus for efficient power control of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift in output power of the RF amplifier.

Abstract: A restraint system for restraining a lower body portion of an individual within a seat including a rigid member configured to selectively restrain the lower body portion such that the lower body portion of the individual is movable only within a predefined area of movement. The rigid member is mounted to the seat and is capable of movement between a stowed position and a deployed position. The lower body portion is restrained by the rigid member when in the deployed position. A locking mechanism locks the rigid member in the stowed position and the deployed position. A release mechanism is associated with the locking mechanism. The release mechanism is located at a predetermined distance from the locking mechanism such that the release mechanism is located outside of the area of movement.

Abstract: A suction dampening device comprises a housing with an inlet port formed therein and a valve case disposed adjacent the inlet port. The valve case includes at least one opening formed therein. A valve core is slidably disposed within the valve case. A lever having an axis of rotation fixed to a portion of the valve case includes a first lever arm disposed to a first side of the axis of rotation and a second lever arm disposed to a second side of the axis of rotation. The second lever arm abuts an outer circumferential surface of the valve core. A spring element is disposed between the first lever arm and the valve core. The spring element is configured to apply a force to the first lever arm to cause the second lever arm to apply a lateral force to the valve core to dampen vibrations of the spring element.

Abstract: A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

Abstract: Methods and apparatuses for use in tuning reactance are described. Open loop and closed loop control for tuning of reactances are also described. Tunable inductors and/or tunable capacitors may be used in filters, resonant circuits, matching networks, and phase shifters. Ability to control inductance and/or capacitance in a circuit leads to flexibility in operation of the circuit, since the circuit may be tuned to operate under a range of different operating frequencies.

Abstract: Methods and devices are described for compensating an effect of aging due to, for example, hot carrier injection, or other device degradation mechanisms affecting a current flow, in an RF amplifier. In one case a replica circuit is used to sense the aging of the RF amplifier and adjust a biasing of the RF amplifier accordingly.

Abstract: Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are presented, where the amplifier can be an envelope tracking amplifier. Circuital arrangements to generate reference gate-to-source voltages for biasing of the gates of the transistors of the stack are also presented. Particular biasing for a case of an input transistor of the stack is also presented.

Abstract: Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are presented, where the amplifier can have a varying supply voltage that varies according to a control voltage. The control voltage can be related to a desired output power of the amplifier and/or to an envelope signal of an input signal to the amplifier. Particular biasing for selectively controlling the stacked transistors to operate in either a saturation region or a triode region is also presented. Benefits of such controlling, including increased linear response of an output power of the amplifier, are also discussed.

Abstract: Methods and devices are described for compensating an effect of aging due to, for example, hot carrier injection, or other device degradation mechanisms affecting a current flow, in an RF amplifier. In one case a replica circuit is used to sense the aging of the RF amplifier and adjust a biasing of the RF amplifier accordingly.