In current WDM networks, it is possible to support hundreds of WDM channels on a single fiber. Therefore, the cost of the transmitters and the receivers, and hence the number of light paths, is becoming the main factor in determining the cost of a WDM network. Researchers tried to keep the number of light paths required to implement a topology as low as possible. This paper presents a restorabl...

This paper presents the electromagnetic (EM) 3-D modeling, hardware measurement, and optimization of hybrid packaged electro-optical transmitters. The initial application is targeted for 10 Gb/s Ethernet and SONET fiber optic communication links. The hybrid package includes a micromachined silicon optical bench, a InP laser and monitor photodiode, a hermetically-sealed lid, integrated impedance...

UMTS transmitters in handsets, based on WCDMA, have to fulfill contradicting requirements. On the one hand, they should operate in a highly power efficient way because battery lifetime is a major consideration for handsets. For this purpose, the application of switchedmode RF power amplifiers seems to be advantageous. On the other hand, the spectral efficiency of the transmitted signal has to b...

A sliding k-transmitter in an orthogonal polygon P is a mobile guard that travels back and forth along an orthogonal line segment s inside P . It can see a point p ∈ P if the perpendicular from p onto s intersects the boundary of P at most k times. We show that guarding an orthogonal polygon P with the minimum number of k-transmitters is NP-hard, for any fixed k > 0, even if P is simple and mon...

Nowadays the main driving parameters for the radio transmitter research are: energy efficiency, frequency re-configurability and integration. Pulsed transmitter architectures have attracted large interest in the recent years due to their potential to meet these demands. In pulsed transmitters, a highly efficient switch mode power amplifier (SMPA) is used in conjunction with a pulse modulator to...

The integration of widely-tunable sampled-grating lasers with semiconductor optical amplifiers and either electroabsorption or Mach-Zehender modulators has been successful in creating high-performance optical transmitters. Details of this performance as well as recent advances in this technology will be reviewed in this paper. Introduction The desire to reduce operational costs with a universal...

A long-term aim of current research into the frequency assignment problem is to identify features that would enable us to classify instances of the problem in terms of certain easily-computed parameters. Although there are good mathematical reasons why this may be impossible in full generality, experimental evidence is emerging which suggests that instances which occur in practice may be amenab...

BACKGROUND There is public concern regarding potential health effects of radiofrequency electromagnetic fields (RF-EMF) emitted by fixed site transmitters. We therefore investigated whether self-reported general well-being in adolescents is affected by RF-EMF exposure from mobile phone base stations (downlink) and broadcast transmitters (TV and radio). METHODS In a prospective cohort study, 4...

LCC compensation network is a commonly used primary compensated topology for wireless power transmission. In this paper, we investigate the utilizing switches two transmitters with strong inter-coupling. First, drawbacks of current are analyzed in aspects over-voltage, loss, and reactive power. Then, an modified switch location proposed to provide no extra loss additional idle coil. After that,...