FET amplifier

About: FET amplifier is a research topic. Over the lifetime, 7048 publications have been published within this topic receiving 77549 citations.

Field effect transistor cable television line amplifier

Abstract: An amplifier circuit for a cable access television line amplifier includes a first cascode amplifier (Q1, Q3) and a second cascode amplifier (Q2, Q4) coupled in a push-pull arrangement. An alternative amplifier circuit includes a first transimpedance amplifier (Q1) and a second transimpedance amplifier (Q2) coupled in a push-pull arrangement. The first transimpedance amplifier further includes a field effect transistor (Q3) as an active load so as to provide feedback and the second transimpedance amplifier further includes a field effect transistor (Q4) as an active load so as to provide feedback.

Linearity optimization of a high power Doherty amplifier based on post-distortion compensation

Abstract: The linearity of a 30-W high-power Doherty amplifier is optimized using post-distortion compensation. A balanced high-power Doherty amplifier using two push-pull laterally-diffused metal-oxide semiconductor (LDMOS) field-effect transistors (FETs) is linearized by optimum adjustment of the peaking compensation line, shunt capacitors, and gate biases. The measured results of an optimized Doherty amplifier for a four-carrier wideband code division multiple access (W-CDMA) signal, achieved -43 dBc adjacent channel leakage ratio (ACLR) at a /spl plusmn/5 MHz offset frequency. This is an ACLR improvement of 12.2dB and 6.5dB in comparison to the Doherty amplifier before optimization and a ClassAB amplifier, respectively.

Traveling wave semiconductor laser amplifier detectors

Abstract: Near-traveling-wave semiconductor laser amplifiers for amplification and detection of optical signals are discussed. Measurements of gain, responsivity, and bandwidth are presented and compared with theory. The system performance of the laser amplifier detector is evaluated by a digital transmission experiment. The importance of using low-reflectivity amplifiers with high-responsivity and weakly wavelength-dependent devices is revealed by computer simulations. The various noise contributions of the laser amplifier detector are analyzed. Expected sensitivity values are given, and it is shown that there exists an optimum amplifier gain with respect to sensitivity. >

High gain wideband driver amplifier

Abstract: Methods and circuitry for implementing monolithic high gain wideband amplifiers. The invention implements an amplifier with a limiter that also performs a signal dividing function. In a specific embodiment, the limiter is designed to make available two in-phase outputs that are then used to drive two gate input lines of a combiner distributed amplifier.

HEMT-HBT doherty microwave amplifier

Abstract: A microwave amplifier and more particularly to a microwave amplifier configured as a Doherty amplifier. The amplifier includes a carrier amplifier, a peak amplifier, a Lange coupler at the input of the amplifiers and quarter wave amplifier at the output of the amplifiers. In order to further increase the efficiency, the Doherty amplifier is formed from HEMT/HBT technology to take advantage of the low-noise performance of HEMTs and the high-linearity of HBTs to form a relatively efficient amplifier that functions as a low-noise amplifier at low power levels and automatically switches to high-power amplification for relatively high-impact RF power levels.