Residual Noise Identification for PIM Measurement Systems using Variable Low-PIM Termination

<p>In this letter, we describe the design for the variable low-PIM termination composed of the voltage-controlled IM-source, a fixed attenuator, and a linear attenuator.</p> <p>The design method for evaluating PIM-level of the fixed attenuator is presented in order not to limit the variable range of entire termination.</p> <p>It is possible to maintain low-PIM performance in spite of using active voltage-controlled IM-source, whose IM level is extremely high. </p> <p>This termination is used for a dynamic residual noise identification for PIM measurement systems by observing the saturation value for voltage sweep.</p> <p>The validity is confirmed by experiments in 2GHz band.</p>

Residual Noise Identification for PIM Measurement Systems using Variable Low-PIM Termination

<p>In this letter, we describe the design for the variable low-PIM termination composed of the voltage-controlled IM-source, a fixed attenuator, and a linear attenuator.</p> <p>The design method for evaluating PIM-level of the fixed attenuator is presented in order not to limit the variable range of entire termination.</p> <p>It is possible to maintain low-PIM performance in spite of using active voltage-controlled IM-source, whose IM level is extremely high. </p> <p>This termination is used for a dynamic residual noise identification for PIM measurement systems by observing the saturation value for voltage sweep.</p> <p>The validity is confirmed by experiments in 2GHz band.</p>

A large gain variable range, high linearity, lownoise, low DC offset VGAs used in BD system

In this paper, a large gain variable range, high linearity, low noise, low DC offset VGAs with a simple gain-dB variable circuit are introduced. In the VGAs chain, the last and the first VGAs employ Bipolar transistors, to improve the linearity and noise characteristics. And the middle three stages VGAs employ MOS transistors. The whole circuitry is designed in 0.35um BiCMOS process, including variable gain amplifiers (VGAs) , fixed gain amplifiers , gain control and DC offset cancellation parts. The automatic gain control loop (AGC) provides a process independent gain variable range of 60dB (including 50dB gain-dB-linearity variable range), with a 200us loop lock time, the VGAs provide a 73dB largest gain, the THD is less than 1% at a 1V(P-P) output level; the equivalent output integral noise is 0.011v/√hz@20MHz bandwidth. The whole area is 1173um*494 um, and the power is 7.1mA at 3.3V signal supply voltage.

Charge transport variation from Bloch–Grüneisen to Mott variable range hopping and transport change due to hydrogenation in Palladium thin films

We report a systematic investigation of the differences in charge transport mechanism in ultra-thin nano-island like films of palladium with thickness varying between 5 nm and 3 nm. The thicker films were found to be metallic in a large temperature range with a dominant Bloch–Grüneisen mechanism of charge transport arising due to electron-acoustic phonon scattering. These films were also found to exhibit an additional electron–magnon scattering. At temperatures below 20 K, the two films displayed a metal-insulator transition which was explained using Al’tshuler’s model of increased scattering in disordered conductors. The thinner films were insulating and were found to exhibit Mott’s variable range hopping mechanism of charge transport. The thinnest film showed a linear decrease of resistance with an increase in temperature in the entire temperature range. The island-like thin films were found to display very different response to hydrogenation at room temperature where the metallic films were found to display a decrease of resistance while the insulating films were found to have an increase of resistance. The decrease of resistance was ascribed to a hydrogen induced lattice expansion in the thin films that were at the percolation threshold while the resistance increase to an increase in work function of the films due to an increased adsorption of the hydrogen atoms at the surface sites of palladium.

Comparison of CP-PC-SAFT and SAFT-VR-Mie in Predicting Phase Equilibria of Binary Systems Comprising Gases and 1-Alkyl-3-methylimidazolium Ionic Liquids

This study compares performances of the Critical Point-based revision of Perturbed-Chain SAFT (CP-PC-SAFT) and the SAFT of Variable Range and Mie Potential (SAFT-VR-Mie) in predicting the available data on VLE, LLVE, critical loci and saturated phase densities of systems comprising CO, O2, CH4, H2S, SO2, propane, the refrigerants R22, R23, R114, R124, R125, R125, R134a, and R1234ze(E) and ionic liquids (ILs) with 1-alkyl-3-methylimidazolium ([Cnmim]+) cations and bis(trifluoromethanesulfonyl)imide ([NTf2]−), tetrafluoroborate ([BF4]−) and hexafluorophosphate ([PF6]−) anions. Both models were implemented in the entirely predictive manner with k12 = 0. The fundamental Global Phase Diagram considerations of the IL systems are discussed. It is demonstrated that despite a number of quantitative inaccuracies, both models are capable of reproducing the regularities characteristic for the considered systems, which makes them suitable for preliminary estimation of selectivity of the ILs in separating various gases.

Mapping the contours of humour: reflections on recent introductory studies

Introductions to fields of studies are almost a sub-genre in their own right, but are often resistant to direct comparison. The essay discusses four recent introductions to humour published by university presses, and what more broadly they may signify about disciplinary advertisement and consolidation. It emphasises a range of difficulties endemic to the study of humour arising from its interdisciplinarity, recent establishment, the variable range of humour and its putative universality; in which context it pays attention to Austinian performatives, puns and their translation, and to the shared propensity in these introductions to mythologise the history of humour theory. Most critical attention is paid to the studies that form almost polar opposites: Nilsen & Nilsen, The Language of Humour and Attardo, The Linguistics of Humour.

Structures, Electronic Properties and Carrier Transport Mechanisms of Si Nano-Crystalline Embedded in the Amorphous SiC Films with Various Si/C Ratios

Recent investigations of fundamental electronic properties (especially the carrier transport mechanisms) of Si nanocrystal embedded in the amorphous SiC films are highly desired in order to further develop their applications in nano-electronic and optoelectronic devices. Here, Boron-doped Si nanocrystals embedded in the amorphous SiC films were prepared by thermal annealing of Boron-doped amorphous Si-rich SiC films with various Si/C ratios. Carrier transport properties in combination with microstructural characteristics were investigated via temperature dependence Hall effect measurements. It should be pointed out that Hall mobilities, carrier concentrations as well as conductivities in films were increased with Si/C ratio, which could be reached to the maximum of 7.2 cm2/V∙s, 4.6 × 1019 cm−3 and 87.5 S∙cm−1, respectively. Notably, different kinds of carrier transport behaviors, such as Mott variable-range hopping, multiple phonon hopping, percolation hopping and thermally activation conduction that play an important role in the transport process, were identified within different temperature ranges (10 K~400 K) in the films of different Si/C ratio. The changes from Mott variable-range hopping process to thermally activation conduction process with temperature were observed and discussed in detail.