We present the results of the experimental study and comparison of Yb-free, Erdoped, all-fiber, alignment free, single frequency (SF) fiber amplifiers operating under 980-, 1470and 1530-nm pumping for the coreand clad-pumping architectures. In the single-mode core-pumped configuration Er-doped fiber amplifiers demonstrated 52% and 60% pump to output efficiencies for 980 and 1480 nm pump wavelen...

This paper presents the design of high gain and low power fully differential Operational Transconductance Amplifier(OTA). Both the main conventional OTA and the boosting amplifiers are fully differential folded cascode.To increase the open-loop gain of the main OTA two auxiliary operational amplifiers(op-amps) are used . These auxiliary op-amps are fully differential folded cascode op-amps with...

In this paper, a new amplification scheme for adaptive MIMO systems is proposed and tested. In this “hybrid amplification” configuration, different amplifiers with different peak powers are used. In this way, each transmitter RF chain has a different DC-power consumption behavior. The adaptation algorithm, which chooses power and rate for each transmitter, uses these different amplifier behavio...

In this paper, we present new results in the development of a broad-band spatial power-combining system implemented in a standard X-band waveguide environment. Using 24 off-the-shelf GaAs monolithic-microwave integrated-circuit (MMIC) power amplifiers integrated with tapered-slot antenna arrays, the new combining circuit produced up to 126-W maximum power output with a gain variation of 1.9 dB ...

Due to the high increase in and demand for a wide assortment of applications that require low-cost, high-efficiency, and compact systems, RF power amplifiers are considered the most critical design blocks and power consuming components in wireless communication, TV transmission, radar, and RF heating. Therefore, much research has been carried out in order to improve the performance of power amp...

GaN high electron mobility transistors (HEMTs) have shown the potential to be extremely tolerant of the space radiation environment. AlGaN/GaN HEMT structures on three different substrates were exposed to proton irradiation at fluences up to 6x10 14 cm -2 , which resulted in a 30% reduction in mobility and saturation current density. Dynamic ON-resistance measurements demonstrated increased deg...

The main objective of this paper is to present a position control design DC-motor, where the set-point externally supplied. controller conceived by using vibrational theory and implemented just processing time derivative Hall-effect sensor signal. Vibrational robust against model uncertainties. Hence, for design, simple mathematical DC-Motor invoked. Then, realized utilizing analog electronics ...

There is a need among scientists and clinicians for low-noise low-power biosignal amplifiers capable of amplifying signals in the millihertz-to-kilohertz range while rejecting large dc offsets generated at the electrode–tissue interface. The advent of fully implantable multielectrode arrays has created the need for fully integrated micropower amplifiers. We designed and tested a novel bioamplif...

Multistage amplifiers have become appropriate choices for high-speed electronics and data conversion. Because of the large number high-impedance nodes, frequency compensation has biggest challenge in design multistage amplifiers. The new technique this study uses two differential stages to organize feedforward feedback paths. Five Miller loops a 500-pF load capacitor are driven by just tiny com...

In this paper, we investigate the parameters affecting Total Harmonic Distortion (THD) and Power Supply Rejection Ratio (PSRR) in PWM Class D Amplifiers (CDAs) on the basis of linear models with feedback. From our mathematical analysis, we show that the THD of a PWM Class D amplifier with feedback can be improved by increasing the gain of the integrator through adding another amplifier at the o...