A CMOS multichannel 10-Gb/s transceiver

We describe a CMOS multichannel transceiver that transmits and receives 10 Gb/s per channel over balanced copper media. The transceiver consists of two identical 10-Gb/s modules. Each module operates off a single 1.2-V supply and has a single 5-GHz phase-locked loop to supply a reference clock to two transmitter (Tx) channels and two receiver (Rx) channels. To track the input-signal phase, the Rx channel has a clock recovery unit (CRU), which uses a phase-interpolator-based timing generator and digital loop filter. The CRU can adjust the recovered clock phase with a resolution of 1.56 ps. Two sets of two-channel transceiver units were fabricated in 0.11-/spl mu/m CMOS on a single test chip. The transceiver unit size was 1.6 mm /spl times/ 2.6 mm. The Rx sensitivity was 120-mVp-p differential with a 70-ps phase margin for a common-mode voltage ranging from 0.6 to 1.0 V. The evaluated jitter tolerance curve met the OC-192 specification.     

Crosslinked acrylic pressure‐sensitive adhesives. II. Effect of humidity on the crosslinking reaction

The effect of humidity during storage on the crosslinking reactions of isocyanate groups was investigated with attenuated total reflectance Fourier transform infrared spectroscopy with pressure‐sensitive adhesives composed of poly[ethyl acrylate‐co‐(2‐ethylhexyl acrylate)‐co‐(2‐hydroxyethyl methacrylate)] as a base resin and polyisocyanate as a crosslinker. A peak‐resolving analysis of the amide II region revealed four bands. According to an analysis of the Fourier transform infrared spectra of the model compounds, these four bands were assigned to free urethane linkages, hydrogen‐bonded urethane linkages, free urea linkages, and hydrogen‐bonded urea linkages. As expected, storage under humid conditions led to the formation of free and hydrogen‐bonded urea linkages corresponding to the promotion of isocyanate consumption. Peak resolution of the amide II region was found to be a reasonable way of monitoring urethane and urea linkages during crosslinking reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3039–3045, 2003     

Fault section detection system for 66 kV underground branchtransmission lines using optical magnetic field sensors

A fault section detection system that uses optical magnetic field sensors and instantly detects the section in which a ground fault occurred was developed for 66 kV underground multiterminal systems having Y-branch joint boxes. The optical magnetic field sensor, which is based on the Faraday effect in Bi-doped YIG ((BiYbGd)₃Fe₅O₁₂) having a large Verdet constant, detects cable conductor currents of 0 to 2000 A with high precision with the use of a laminated magnetic ring core of silicon steel plates. Sensors and a fault section detector/indicator of a system are connected with optical fibers capable of nonrepeated transmission of over 6 km     

Photoresponsive peptide and polypeptide systems: part II. Photochromism of poly(l-ornithine) containing various azo-contents in side chains

Poly(L-ornithine)s having various azo-contents in the side chains were synthesized by the water-soluble carbodiimide procedure. The photochemical properties of the polypeptides poly[N^δ-p-(phenylazo)benzoyl-L-ornithine] (PPABLO) containing 3–77 mol% azobenzene were investigated by absorption and circular dichroism spectroscopy in hexafluoro-2-propanol (HFIP) or water, and in HFIP-water or methanol-water solvent mixtures. The photochromism of the dichroic bands of the PPABLOs containing 20–77 mol% azobenzene in the visible and ultraviolet wavelength regions was found to be mostly reversible as a function of irradiation time at different wavelengths due to the photostationary state (above 80% trans-cis photoisomerization) of the azo aromatic moieties. The PPABLO containing 3.2 mol% azobenzene in water exhibited conformational changes from random coil to helix by the addition of methanol or sodium dodecyl sulphate (SDS). The photo-induced conformational change was observed in HFIP-water-SDS solvent mixtures, while no conformational change was seen in water and HFIP-water solvent mixtures.     

Soft-decision Viterbi decoding with diversity combining formulti-beam mobile satellite communication systems

Diversity combining methods for mobile satellite communication systems employing convolutional encoding and soft-decision Viterbi decoding are evaluated. Computer simulation clarifies that the pre-Viterbi-decoding maximal ratio combining method has better performance than other methods in Rician fading channels. The simulation results agree with the Pe (bit error probability) performance derived from the numerical analysis for slow fading using the approximate Pe performance of Viterbi decoding in AWGN (additive white Gaussian noise) channels and the probability density function of Rician fading. Applying this diversity method to the multi-beam mobile satellite communication systems, a satellite beam diversity reception scheme is proposed. A computer simulation result shows that the proposed scheme decreases the packet error rate of the control signals to less than 1/100 around the satellite beam boundary     

Complexity of the color appearance of objects with nonuniform illumination

An inversion relationship is clarified between lightness and brightness, and also between chroma and colorfulness under nonuniform illumination with different illuminance levels (high and low) within the same visual field. Brightness (or colorfulness) of object color with low lightness (or chroma) under high illuminance level is perceived higher than that of another object color with high lightness (or chroma) under low illuminance level. Two color images are given for showing the inversion phenomena on brightness–lightness and colorfulness–chroma between object colors under different illuminance levels. These color images are useful for making researchers on color understand the differences in concept between brightness and lightness, and also between colorfulness and chroma. In particular, the concept of colorfulness is important, but difficult to understand. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 372–377, 2007     

Optical data storage by novel photoelectrochromic polymer

A novel elastic polymer containing 4,4′-bipyridinium salts with tetrakis[3,5-bis(trifluoromethyl)phenyl]borate as part of the main chain was synthesized. The cast film showed persistent and reversible colour changes due to photoinduced electron transfer upon excitation of an ion-pair charge-transfer band (_ex >365 nm) in vacuo. The lifetime of the coloured state markedly depended on temperature. The optically written data were stored without decay below 0°C and were erased thermally at elevated temperatures. The colour changes were reversibly repeatable for many times.     

Transient phase conjunction in a two-level system

An analytical expression for conjugate signals is developed for a case where three rectangular pulses with the same center frequency are injected into a two-level system. The Maxwell's equation is solved with the slowly varying envelope approximation and with the perturbative third-order nonlinear polarization expression of a two-level system. Numerical examples are discussed in such a way that the input pulsewidth is changed relative to the energy relaxation and dephasing times. As the optical pulsewidth becomes short, ripples appear in the signal pulse due to the beat between the optical field and the resonant oscillation of the atomic system     

Molecular beam epitaxial growth of SrO and CaO with RHEED intensity oscillation

SrO and CaO, related compounds of BSCCO superconductor, are grown onto SrTiO₃(100) substrates with molecular beam epitaxy(MBE) technique. During growth, the specular spots of RHEED patterns show intensity oscillations, indicating two dimensional growth. The periods of oscillations are utilized to calculate the atom fluxes. It is shown that sublimation processes of both Sr and Ca metals in the effusion cells are stable under the growth condition of oxide films. The periods of oscillations during the SrO growth are independent of substrate temperature, confirming that Sr atoms are oxidized immediately and stay on the substrate surface without re-evaporation. These informations are practically available for precise control of the atomic layer controlled MBE of BSCCO superconductor thin films.On leave from Superconductiivity Research Laboratory, ISTEC.