Abstract: Most semiconductor devices manufactured today, have uniform dopant concentration, either in the lateral or vertical device active (and isolation) regions. By grading the dopant concentration, the performance in various semiconductor devices can be significantly improved. Performance improvements can be obtained in application specific areas like increase in frequency of operation for digital logic, various power MOSFET and IGBT ICS, improvement in refresh time for DRAM's, decrease in programming time for nonvolatile memory, better visual quality including pixel resolution and color sensitivity for imaging ICs, better sensitivity for varactors in tunable filters, higher drive capabilities for JFET's, and a host of other applications.
Abstract: The present disclosure relates to transmission circuitry of a wireless communication device. The transmission circuitry includes power amplifier circuitry, an output matching network, and impedance control circuitry. The power amplifier circuitry amplifies a radio frequency (RF) input signal to provide an amplified RF output signal, which is passed through the output matching network and transmitted via one or more antennas. As the center frequency of the RF input signal and conditions of operating parameters change, the impedance control circuitry adjusts the values of one or more variable impedance elements of the output matching network in a desired fashion. The values of the variable impedance elements are adjusted such that the output matching network concurrently and dynamically presents the desired load impedances at the center frequency and at one or more harmonics of the RF input signal to achieve a given performance specification.
November 1, 2010
May 3, 2012
Christopher Harris, Raymond Sydney Pengelly
Abstract: Amplifier systems and methods are provided which closely approximate a constant output impedance and a constant quiescent output signal during forward and reverse modes of operation. The systems can be realized with small, inexpensive components that are compatible with integrated-circuit fabrication processes. A system embodiment includes a signal amplifier, a feedback path that is coupled across at least part of the signal amplifier to reduce its impedance, a reverse amplifier which is coupled to drive at least a feedback portion of the feedback path and a signal generator which controls operational timing of the signal amplifier and reverse amplifier. Another system embodiment includes an error-current canceler that cancels error currents of the signal amplifier with substantially equal and opposite correction currents.
Abstract: The invention relates to a trench bipolar transistor structure, having a base 7, emitter 9 and collector 4, the latter being divided into a higher doped region 3 and a lower doped drift region 5. An insulated gate 11 is provided to deplete the drift region 5 when the transistor is switched off. The gate 11 and/or doping levels in the drift region 5 are arranged to provide a substantially uniform electric field in the drift region in this state, to minimise breakdown. In particular, the gate 11 may be seminsulating and a voltage applied along the gate between connections 21,23.
July 25, 2002
February 13, 2003
KONINKLIJKE PHILIPS ELECTRONICS N.V.
Raymond J.E. Hueting, Jan W. Slotboom, Petrus H.C. Magnee
Abstract: A voltage controlled oscillator includes N (N is an integer equal to or more than 2) inversion-type differential amplifiers and a level converter. The N (N is an integer equal to or more than 2) inversion-type differential amplifiers are connected in a loop such that each of output signals outputted from one of the N inversion-type differential amplifiers has an opposite polarity to a corresponding one of output signals outputted from the next one of the N inversion-type differential amplifiers. The level converter is connected to one of the N inversion-type differential amplifiers as a last inversion-type differential amplifier to generate an oscillation signal from the output signals outputted from the last inversion-type differential amplifier. Each of the N inversion-type differential amplifiers operates in response to a predetermined voltage and a control voltage.
Abstract: The amplifier is intended for use in situations where a considerable distance separates the instrument (for example a piezo-electric transducer) to be monitored and the control room. The amplifier comprises a charge/current converter for converting the charge output of the instrument into a current signal, the charge/current converter being connected to operate as a high impedance current source, a current/voltage converter and a connecting cable connecting the current output of the charge current converter to the input of the current/voltage converter.
Abstract: The invention utilizes a four-port hybrid junction in which a signal to be amplified or a low level stable reference signal is coupled to a first port in which a pair of similar or matched amplifiers or oscillators are coupled to the respective second and third ports of the hybrid, and in which the resulting amplified or coherent stabilized power of the two amplifiers or oscillators is provided at the fourth port of the hybrid junction.