98results about How to "Reduce Impedance Mismatch" patented technology

A method for tuning a transmitter in order to improve impedance matching to an antenna or to intermediate radio frequency stages uses an error detector that senses a deviation of the amplitude or phase angle of a load current of a power amplifier driver or of a power amplifier. A controller calculates a correction and dynamically adjusts tunable transmitter parameters, which may include values of components in matching networks or bias voltages in the power amplifier or the power amplifier driver, so as to reduce the deviation and thereby improve the impedance matching. The load current of the power amplifier may alternatively be sensed by measuring the duty cycle of its switching mode power supply. A transmitter having a power amplifier and one or more tunable circuit elements incorporates an error detector that senses the amplitude or phase of a load current and a controller that adjusts one or more tunable parameters to reduce impedance mismatch. An integrated circuit device suitable for use in a transmitter includes a power amplifier driver circuit and a detector circuit capable of sensing a load current, and a controller circuit that can adjust tunable parameters either within or external to the integrated circuit. By eliminating directional couplers and integrating the detectors and power amplifier drivers, the size, complexity, and cost of wireless transceivers can be reduced, while efficiency and power consumption are improved through the dynamic adjustment of operating points and impedance matching.

A power amplifier includes: an amplifying transistor; a bias circuit; a first diode; a second diode; a matching attenuating circuit; a first current mirror circuit; a serial resonant circuit, and a switch. In an amplification mode, the bias circuit supplies a bias current to the amplifying transistor, and the first current mirror circuit turns off the first and second diodes, and the switch. In an attenuation mode, the bias circuit supplies no bias current to the amplifying transistor, and the first current mirror circuit turns on the first and second diodes and the switch.

The invention discloses a RF coaxial connector, which includes a socket and an adapter. The socket includes an outer conductor and a center conductor. The adapter includes a plug capable of being inserted into the socket. The adapter also includes an outer conductor and a center conductor that can be in contact with the outer conductor and the center conductor of the socket, respectively. A dumbbell-shaped first insulating body is disposed inside the plug of the adapter and filled between the outer conductor and the center conductor of the adapter. The first insulating body has a middle portion narrower than two end portions thereof such that an annular gap is formed between the middle portion of the first insulating body and the outer conductor of the adapter, thereby forming different impedance regions at the connection regions of the plug and the socket. Therefore, a high impedance region and a low impedance region can compensate each other so as to decrease the adverse effect of the high impedance region on the connector performance and improve electrical and RF performance of the product. Compared with the prior art, the connector of the present invention allows a larger axial offset.