A mismatch detector including a directional device adapted to couple signals across the device and a detector coupled to a port on the directional device and configured to measure a reflected power a second detector coupled to a port on the directional device and configured to measure a transmit power. The mismatch detector may be used in wireless communication devices, including, but not limited to mobile wireless devices, base stations, and communication systems.

Systems and methods for controlling output power in a communication device

RF power transmission, modulation, and amplification embodiments

A RF power amplifier circuit has at least one power transistor and a protection circuit protecting the power transistor against high voltages that lead to a destructive breakdown of the transistor. The circuit comprises a power transistor (2), a biasing circuit (6) biasing the power transistor; a peak detector (8) measuring the output voltage of the power transistor; and a comparator circuit (12) connected to the peak detector (8) and designed to reduce the base current of the power transistor (2) when controlled by the peak detector (8).

Rf power amplifier circuit

Systems and methods of RF power transmission, modulation, and amplification, including embodiments for compensating for waveform distortion

An apparatus, system, and method are provided for energy conversion. For example, the apparatus can include a trans-impedance node, a reactive element, and a trans-impedance circuit. The reactive element can be configured to transfer energy to the trans-impedance node. The trans-impedance circuit can be configured to receive one or more control signals and to dynamically adjust an impedance of the trans-impedance node. The trans-impedance node, as a result, can operate as an RF power switching supply based on the one or more control signals.

Systems and Methods of RF Power Transmission, Modulation, and Amplification

A mismatch protection circuit to protect power output transistors of a communications transmitter from damaging excessive reflected power, as might occur when the antenna is disconnected or broken, which circuit continuously monitors and compares parameters indicative of forward and reflected power or VSWR and when there is excessive mismatch, instantaneously cuts back the dc power delivered to the output transistors to a safe low level, but a level sufficient for continued cutback operation of the protection circuit, when and for so long as the excessive mismatch continues.

D Bowman

Papers

Circuit to protect rf output amplifier against mismatch damage