Sensitivity to carrier frequency offset (CFO) is one of the biggest drawbacks of orthogonal frequency division multiplexing (OFDM) system. A lot of CFO estimation algorithms had been studied for compensation of CFO in OFDM system. However, with the adoption of direct-conversion architecture (DCA), which introduces additional impairments such as dc offset (DCO) and in-phase/quadrature (I/Q) imba...

This paper presents a step up DC-to-DC converter with hybrid switch capacitor technique having high voltage conversion ratio with small switch voltage stress . The converter is suitable for the applications where high voltage conversion is required. The proposed DC-DC converter has low voltage ratted MOSFET switch and is connected to PV array to get high output voltage at small duty ratios. Hen...

We show that a finite Josephson Junction (JJ) chain, ending with two bulk superconductors, and with a weak link at its center, may be regarded as a condensed matter realization of a two-boundary Sine-Gordon model. Computing the partition function yields a remarkable analytic expression for the DC Josephson current as a function of the phase difference across the chain. We show that, in a suitab...

If the lines which connect the output terminal of DC-DC converter and the load are long, the voltage actually across load will be changed largely to produce the voltage drops by the impedances of the lines. Then, the terminal which senses the voltage across load is prepared apart from the output terminal of DC-DC converter, and it leads to the load, and the voltage across load is adjusted so th...

A novel current controlled CMOS ring oscillator is presented in this paper. Specially circuit structure and transistor parameters design is used to obtain good temperature coefficient. The designed ring oscillator circuit has been used in a CMOS step-up switching regulator controller which has been implemented using a 0.5μm double poly double metal CMOS technology. The test result shows that th...

Submitted: Jun 8, 2013; Accepted: Jul 17, 2013; Published: Jul 25, 2013 Abstract: In this paper different types of converters based on different types of switching cells have been studied and designed. The analysis of each converter has been carried out. The main objective of analysis is to find out the advantages and disadvantages of each converter and to find the converter suitable for the gi...

This paper describes the analysis and design of a low cost three phase inverter brushless dc motor (BLDC) drive.For effective utilization of the developed system, a novel direct current controlled pwm scheme (DPC)is designed and implemented.. The operational principle of the four-switch BLDC motor drive and the developed control scheme are theoretically analyzed and the performance is demonstra...

A new auxiliary circuit that can be implemented in DC-DC and AC-DC ZVS-PWM converters is proposed in the paper. The circuit is for ZVS-PWM converters used in applications where high-frequency operation is needed and the load current is higher than that of typical ZVS-PWM converters. In the paper, the operation of a new ZVS-PWM converter is described, its steady-state operation is analyzed, and ...

In this paper, the dynamics of a DC-DC boost power converter under variable structure control is studied applying bifurcation analysis techniques. The switching hyperplane coefficients are considered as bifurcation parameters. The dynamic phenomena detected in this work suggest new types of sliding bifurcations. This analysis is relevant in the context of sliding mode control with auxiliary ada...

A protocol is described which allows to send and receive messages anonymously using an arbitrary communication network, and it is proved to be unconditionally secure. This improves a result by DAVID CHAUM: The DC-net guarantees the same, but on the assumption of a reliable broadcast network. Since unconditionally secure Byzantine Agreement cannot be achieved, such a reliable broadcast network c...