A coplanar X-band AlGaN/GaN power amplifier MMIC on s.i. SiC substrate

This work presents a two-stage high-power amplifier monolithic microwave integrated circuit (MMIC) operating between 9 GHz and 11 GHz based on a fully integrated AlGaN/GaN high electron mobility transistor (HEMT) technology on s.i. SiC substrate and is suitable for radar applications. The MMIC device with a chip size of 4.5/spl times/3 mm/sup 2/ yields a linear gain of 20 dB and a maximum pulsed saturated output power of 13.4 W at 10 GHz equivalent to 3.3 W/mm at V/sub DS/=35V, 10% duty cycle, and a gain compression level of 5 dB. Further, dc reliability data are given for the MMIC HEMT technology.     

Single‐Molecule Imaging Reveals that Small Amyloid‐β1–42 Oligomers Interact with the Cellular Prion Protein (PrPC)

Oligomers of the amyloid‐β peptide (Aβ) play a central role in the pathogenesis of Alzheimer’s disease and have been suggested to induce neurotoxicity by binding to a plethora of cell‐surface receptors. However, the heterogeneous mixtures of oligomers of varying sizes and conformations formed by Aβ42 have obscured the nature of the oligomeric species that bind to a given receptor. Here, we have used single‐molecule imaging to characterize Aβ42 oligomers (oAβ42) and to confirm the controversial interaction of oAβ42 with the cellular prion protein (PrP^C) on live neuronal cells. Our results show that, at nanomolar concentrations, oAβ42 interacts with PrP^C and that the species bound to PrP^C are predominantly small oligomers (dimers and trimers). Single‐molecule biophysical studies can thus aid in deciphering the mechanisms that underlie receptor‐mediated oAβ‐induced neurotoxicity, and ultimately facilitate the discovery of novel inhibitors of these pathways.     

Reliability of 50 nm low-noise metamorphic HEMTs and LNAs

The long-term stability of a 50 nm low-noise metamorphic HEMT technology has been investigated by biased accelerated lifetime tests on both MHEMT devices and two-stage LNAs for W-band applications. The lifetime tests were performed at three channel temperatures, a drain voltage of 1 V and a power density of 0.3 W/mm in air. Based on a -10% degradation of g/sub m max/ failure criterion an activation energy of 1.6 eV and a projected median lifetime of 2.7/spl times/10/sup 6/ h at T/sub ch/=125/spl deg/C were determined. The two-stage LNAs were stressed at a channel temperature of 185/spl deg/C for 4000 h. The S-parameters did not show any significant degradation after 4000 h of stress time if the positive threshold voltage shift was compensated for by a corresponding increase of the gate voltage. The reliability results demonstrate the stable operation of 50 nm MHEMTs and LNAs for W-band applications and beyond.     

Agenda Building, Agenda Setting, Priming, Individual Voting Intentions, and the Aggregate Results: An Analysis of Four Israeli Elections

This article reports the findings of the multistage agenda-setting process of four Israeli elections. In the first stage, agenda building, it is demonstrated that there is a close association between real-world indicators and media agenda. In the second stage, agenda setting, it was found that the level of television coverage of issues influences the proportion of surveys' respondents naming these issues as the nation's most important problems. In the third stage, priming, the analysis focused on electoral voting behavior in multiparty parliamentary elections rather than on the usual evaluations of the president's performance. At the individual level, there is evidence for a priming effect. At the aggregate level, the findings suggest that there may be a priming effect on the actual electoral success of various political parties.     

SiGe differential transimpedance amplifier with 50-GHz bandwidth

InP and SiGe technologies are both attractive for design of circuits operating at 40 GB/s and beyond. In this paper, we describe a fully differential SiGe transimpedance amplifier (TIA) suitable for differential phase-shift keying applications. The TIA exhibits 49 dB-/spl Omega/ transimpedance, greater than 50-GHz bandwidth, and input-referred current noise less than 30 pA//spl radic/Hz. For comparison, we have also developed a similar TIA in an InP double-heterostructure bipolar transistor technology. The InP TIA had 48 dB-/spl Omega/ transimpedance and 49-GHz bandwidth.