Note on B-splines, wavelet scaling functions, and Gabor frames

Let g be a continuous, compactly supported function on such that the integer translates of g constitute a partition of unity. We show that the Gabor system (g,a,b), with window g and time-shift and frequency-shift parameters a,b>0 has no lower frame bound larger than 0 if b=2,3,... and a>0. In particular, (g,a,b) is not a Gabor frame if g is a continuous, compactly supported wavelet scaling function and if b=2,3,... and a>0. We give an example for our result for the case that g=B/sub 1/, the triangle function supported by [-1,1], by showing pictures of the canonical dual corresponding to (g,a,b) where ab=1/4 and b crosses the lines N=2,3,.     

<Emphasis Type="Italic">FCC/BCC</Emphasis> competition and enhancement of saturation magnetization in nanocrystalline Co-Ni-Fe films

The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films were investigated using a number of techniques. A high saturation magnetic induction up to B _s = 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed, which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of the composition. The text was submitted by the authors in English.     

Modellierungs- und Simulationsverfahren für die optische Verbindungstechnik auf elektrischen Leiterplatten

Optical interconnection technology on the printed circuit board level is a key technology for future microelectronic equipment. The consideration of functional, technological, and economical requirements results in a hybrid solution, where electrical and optical interconnects are integrated into one substrate called electrical optical printed circuit board. The significant part of the entire design process for electrical optical printed circuit boards is marked by the design supporting modelling and simulation of optical interconnects. Based on an abstract model for an entire optical interconnect a simulation model for optical multimode-waveguides is presented, taking into account all significant waveguide properties. Apart from that, the modeling of active components (laser- and photo-diodes) is addressed.     

A redundant multivalued logic for a 10-Gb/s CMOS demultiplexer IC

A redundant multivalued logic is proposed for high-speed communication ICs. In this logic, serial binary data are received and converted into parallel redundant multivalued data. Then they are restored into parallel binary data. Because of the multivalued data conversion, this logic makes it possible to achieve higher operating speeds than that of a conventional binary logic. Using this logic, a 1:4 demultiplexer (DEMUX, serial-parallel converter) IC was fabricated using a 0.18-/spl mu/m CMOS process. The IC achieved an operating speed of 10 Gb/s with a supply voltage of only 1.3 V and with power consumption of 38 mW. This logic may achieve CMOS communication ICs with an operating speed several times greater than 10 Gb/s.     

Lateral ion implant straggle and mask proximity effect

Lateral scattering of retrograde well implants is shown to have an effect on the threshold voltage of nearby devices. The threshold voltage of both NMOSFETs and PMOSFETs increases in magnitude for conventional retrograde wells, but for triple-well isolated NMOSFETs the threshold voltage decreases for narrow devices near the edge of the well. Electrical data, SIMS, and SUPREM4 simulations are shown that elucidate the phenomenon.     

A New Hand-Held Microsystem Architecture for Biological Analysis

This paper presents a hand-held microsystem based on new fully integrated magnetoresistive biochips for biomolecular recognition (DNA hybridization, antibody antigen interaction, etc.). Magnetoresistive chip surfaces are chemically treated, enabling the immobilization of probe biomolecules such as DNA or antibodies. Fluid handling is also integrated in the biochip. The proposed microsystem not only integrates the biochip, which is an array of 16times16 magnetoresistive sensors, but it also provides all the electronic circuitry for addressing and reading out each transducer. The proposed architecture and circuits were specifically designed for achieving a compact, programmable and portable microsystem. The microsystem also integrates a hand-held analyzer connected through a wireless channel. A prototype of the system was already developed and detection of magnetic nanoparticles was obtained. This indicates that the system may be used for magnetic label based bioassays     

The effect of photon energy and temperature on the persistent tunneling photoconductivity effect in Al/δ(Si)-GaAs structures

The phenomenon of persistent tunneling photoconductivity was studied using the tunneling spectroscopy technique at liquid-helium temperature: the separation between the unoccupied levels in a δ-doped layer at the GaAs surface decreased after illumination. This decrease was due to an increase in the width of the quantum well of the δ-doped layer. For photon energies hv exceeding the GaAs band gap E _g , this increase in the width of the quantum well was related to the accumulation of positive charge in the depth of GaAs induced by the generation of the electron-hole pairs and photoionization of deep centers. For hv < E _g (including the case of CO₂ laser), only photoionization is important. The experimental data agree with the self-consistent calculations. The critical temperature for the effect has been determined (T _c = 45 K); at higher temperatures, the effect disappears.     

Synthesis of an isotropic reradiator for suppression of TE-polarized wave scattering by a perfectly conducting cylinder

The problem of synthesis of an isotropic reradiator providing for the transparency of a circular perfectly conducting cylinder illuminated by a TE-polarized plane wave is investigated. A general solution to the problem of diffraction from the cylinder with a reradiator is obtained, and a system of nonlinear equations for the synthesis problem is derived. Numerical solution of the synthesis problem is illustrated by a number of examples.     

An optically clocked transistor array with dual serial-to-parallel and parallel-to-serial conversion capability for optical label swapping

We propose an optically clocked transistor array optoelectronic integrated circuit (OEIC) for both serial-to-parallel and parallel-to-serial conversion (demux/mux), enabling an interface between high-speed asynchronous burst optical labels and CMOS circuitry for optical label swapping. Dual functionality of the OEIC reduces size, power, and cost of the optical label swapper. The capability for greater than 20-Gb/s conversion operation is demonstrated.     

Operating Penalties in Single-Fiber Operation 10-Gb/s, 1024-Way Split, 110-km Long-Reach Optical Access Networks

We report for the first time optical signal-to-noise penalties which lead to performance degradations in single-fiber long-reach optical access networks when compared to identical dual-fiber systems. A simplified architecture, with reduced optical amplifier count compared to previous work, for single-fiber operation of a symmetrical 10-Gb/s, 1024-way split, 110-km long-reach optical access network is presented and demonstrated. In addition, a possible solution to remove the optical signal-to-noise penalty is suggested