Airborne capacitive micromachined ultrasonic transducers (CMUTs) have predominantly large input reactance with small series radiation resistance. To maximize the acoustic power at resonance we employ low cost LC matching networks between output impedance driving source and CMUT transducer. Conventional networks, including pi T-network topologies are employed to provide a high-Q match. An import...

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...

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...

We study spillovers between REITs and stock markets in a global context. compute both directional net spillover indexes dynamic setting. use LASSO methods to include many our analysis. Our findings indicate that connectedness these is high. On average three REIT one market are volatility transmitters. Considerable time variation observed. Spillovers substantially higher during crises. While wer...

This paper proposes and verifies a SAR measurement procedure for a multi-antenna transmitter that requires the measurement of two-dimensional electric field distributions for the number of antennas and the calculation for obtaining the three-dimensional SAR distributions for arbitrary weighting coefficients of the antennas prior to determining the average SAR. The proposed procedure is verified...

A k-transmitter in a simple orthogonal polygon P is a mobile guard that travels back and forth along an orthogonal line segment s inside P . The k-transmitter can see a point p ∈ P if there exists a point q ∈ s such that the line segment pq is normal to s and pq intersects the boundary of P in at most k points. In this paper, we give a 2-approximation algorithm for the problem of guarding a mon...

We develop and analyze a multiaccess communi-In this paper we present an analysis of a system with just cation model over the additive Gaussian noise channel. The enough complexity to exhibit both aspects of a multiaccess framework is information-theoretic; nonetheless it also incorpo-problem. In the analysis we use tools borrowed from both rates some queuteing-theoretic aspects of the problem....