Now-a-days the new family of dc-dc converters based on three state switching cell and voltage multiplier cells. It present a demonstrate of some advantages and limitations of a several topologies were typically use in voltage step-up applications. The operating principle of this family has chosen the boost converter and discussed in detail. The analysis of converter can applicable in uninterrup...

Visible light communication (VLC) takes advantage of the widespread use light-emitting diodes (LEDs), and by modifying driver stage, LEDs are capable lighting transmitting information. One main drawbacks is low power efficiency due to modification LED stage in order add capability. Most research work related VLC toward task, whereas there a limited about improvement on efficiency. This article ...

DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirel...

Baseband front-end amplifiers operating from DC to several GHz are required from high speed optical transmission systems. Classical direct-coupled baseband transimpedance amplifiers have high gain but their high frequency performance is limited by the parasitic capacitances of the transistors. Their upper frequency limit is empirically known to achieve only a 30% of the transition frequency (fT...

With the introduction of commercially available amplifiers using the current feedback topology by Comlinear Corporation in the early 1980’s, previously unattainable gain and bandwidths in a DC coupled amplifier became easily available to any design engineer. The basic achievement realized by the current feedback topology is to de-couple the signal gain from the loop gain part of the overall tra...

In this paper, we compare two X-band highefficiency switched-mode amplifiers designed around two commercially available packaged MESFET’s, one having a four times larger gate periphery than the other. The amplifiers using the larger and smaller devices are designed to operate in classes E and F, respectively. The smaller device gives 685-mW output power with 7.4-dB gain and 64% overall efficien...

The energy efficiency of battery-operated portable applications can be improved by increasing the efficiency of power amplifiers (PAs). By dynamically changing the supply voltage from the fixed battery supply using a DC-DC converter, the PA can be operated with high efficiency during power back-off. This paper presents the system level requirements for a buck converter and other blocks in a dyn...

With the increasing importance of spectral efficiency in mobile communications, linearity of the RF PA has become a critical design issue for non-constant-envelope digital modulation schemes.1 This issue is particularly significant in spread spectrum applications such as CDMA and wideband CDMA (W-CDMA) base stations, where the peak-to-average ratio of modulated RF signals can vary over a range ...