A radio frequency (RF) system including: a modem configured to generate a first set of digital bits and to create an analog RF signal from those digital bits; a power amplifier configured to receive the analog RF signal and to amplify the analog RF signal, the power amplifier including an input for a biasing voltage; a feedback loop configured to sample an output of the power amplifier, generate a second set of digital bits corresponding to the first set of digital bits, digitally process the second set of digital bits to determine a linearity characteristic of the power amplifier, and to adjust the biasing voltage in response to determining the linearity characteristic.

According to one embodiment, a correction device is used for an apparatus including a coil and a conductor in a vicinity of the coil. The correction device corrects an influence of a magnetic field generated by the conductor when a current flows through the coil. The correction device includes a first measuring device, a second measuring device, and a control device. The first measuring device measures a first signal of the coil. The second measuring device measures a second signal of the coil, which is different from the first signal. The control device estimates the influence acting on the coil, based on a difference between the first signal filtered by a first filter and the second signal filtered by a second filter. Furthermore, the control device controls a command signal for flowing the current to the coil, based on an estimation result of the influence.

A wideband power amplifier module includes a plurality of switch mode amplifiers and a plurality of impedance amplifier modules. Each switch mode amplifier includes an input to receive an input signal, and an RF output to output an RF power signal. The switch mode amplifier includes at least one semiconductor switch formed from gallium nitride (GaN). Each impedance amplifier module includes an output electrically connected to the RF output of a respective switch mode amplifier. The impedance amplifier module is configured to inject at least one impedance control signal to each RF output.

A power module comprises a high frequency switching electronic power conditioner including stacked rectifier/filters, the stacked rectifier/filters generating stacked DC output voltages; and a vacuum electronic device coupled to the high frequency switching electronic power conditioner, the vacuum electronic device including components, each component receiving a respective DC output voltage of the stacked DC output voltages.

Systems and methods for implementing Soft-duplex functionality in an amplifier in a HFC network.

Systems and methods for implementing Soft-duplex functionality in an amplifier in a HFC network.

Circuits and methods related to power amplifiers. In some implementations, a bias circuit includes a reference device connectable to receive a first electrical supply level, the reference device arranged to produce an electrical bias condition using the first electrical supply level, and the reference device connectable to provide the electrical bias condition to an amplifier device connectable to a second electrical supply level. The bias circuit also includes a power density translating circuit connectable between the reference device and the amplifier device, the power density matching circuit provided to substantially set a first power density associated with the reference device and a second power density associated with the amplifier device relative to one another, the first power density being a function of the first electrical supply level and the second power density being a function of the second electrical supply level.

RF amplification system includes a power cavity and a coupling loop operably positioned within the power cavity between an inner conductor and an outer conductor. The coupling loop includes a secured segment that is coupled to the grounding deck and a movable segment that is coupled to the secured segment. The secured segment extends between the grounding deck and the movable segment. The coupling loop defines a loop region that correlates to an amount of inductive coupling between the coupling loop and magnetic field within the power cavity. The movable segment is movable relative to the secured segment while the secured segment is stationary to change a size of the loop region and thereby change the amount of inductive coupling.

A charge pump circuit having first and second input nodes to be coupled to a first power source, and top and bottom output nodes and an intermediate node. The charge pump circuit produces i) a voltage at the top output node that is higher than a voltage of the intermediate node, and ii) a voltage at the bottom output node that is lower than the voltage of the intermediate node. A bias voltage source has i) an input that is to be coupled to a second power source and ii) an output that produces an output voltage, which is a predetermined proportion of an input voltage at the input and that follows the input voltage downward and upward as the input voltage sags and recovers, respectively. The output of the bias voltage source is directly connected to the intermediate node of the output stage. Other embodiments are also described.

A novel and useful radio frequency (RF) front end module (FEM) circuit that provides high linearity and power efficiency and meets the requirements of modern wireless communication standards such as 802.11 WLAN, 3G and 4G cellular standards, Bluetooth, ZigBee, etc. The configuration of the FEM circuit permits the use of common, relatively low cost semiconductor fabrication techniques such as standard CMOS processes. The FEM circuit includes a power amplifier made up of one or more sub-amplifiers having high and low power circuits and whose outputs are combined to yield the total desired power gain. An integrated multi-tap transformer having primary and secondary windings arranged in a novel configuration provide efficient power combining and transfer to the antenna of the power generated by the individual sub-amplifiers.