RF, DC, and Reliability Performance of MIM Capacitors Embedded in Organic Substrates by Wafer-Transfer Technology (WTT) for System-on-Package Applications

In this paper, radio frequency (RF), dc, and reliability performance have been studied on metal-insulator-metal (MIM) capacitors embedded in organic substrates. The MIM structure including ~74-nm SiN dielectric was prefabricated on Si and then transferred onto organic substrates (FR-4) by wafer-transfer technology (WTT). The RF characteristics up to 30 GHz were investigated by equivalent lumped circuit modeling, showing that the parameters associated with the MIM layers including the main capacitance, parasitic inductance, and resistance were only slightly changed by the WTT process. The substrate-related parasitics were reduced as a result of the replacement of lossy Si with insulating FR-4 substrates. Excellent capacitance linearity, low voltage coefficient (~2.2 ppm/V²), and temperature coefficient (~38 ppm/degC) were obtained for capacitors on FR-4 substrates. Current-voltage and time-dependent dielectric breakdown tests verified that, after the harsh processes of WTT, the MIM structures maintained the intrinsic reliability as those originally fabricated on Si. This paper, along with earlier reports, proved that WTT presented a new dimension to realize embedded capacitors for high-density circuit board and system-on-package applications     

Recent Advances in Electrocatalysts for Efficient Nitrate Reduction to Ammonia

Ammonia as an irreplaceable chemical has been widely demanded to keep the sustainable development of the modern society. However, its industrial production consumes huge energy and releases extraordinary green-house gases, leading to various environmental issues. To achieve the green production of ammonia is a great challenge that has been extensively pursued recently. In the review, a most promising strategy, electrochemical nitrate reduction reaction (e-NO₃RR) for the purpose is comprehensively investigated to give a full understanding of its development and mechanism and provide guidance for future directions. Particularly, the development of electrocatalysts is focused to realize the high ammonia yield rate and Faraday efficiency for industrial applications. The recent-developed catalysts, including noble metallic materials, alloys, metal compounds, single-metal-atom catalysts, and metal-free materials, are systematically discussed to review the effects of various factors on the catalytic performance in e-NO₃RR. Accordingly, the strategies, including defects engineering, coordination environment modulating, surface controlling, and hybridization, are carefully discussed to improve the catalytic performance, such as the intrinsic activity and selectivity. Finally, perspectives and challenges are given out. This review shall provide insightful guidance on the development of advanced catalytic systems for the production of green ammonia efficiently in the industry.     

Measurement Biases in the Bender Element Test

This paper reconsiders the signals that are transmitted in bender element tests and the associated transfer functions to identify the problems that bias the velocity (travel time) determination. The findings of the numerical and physical experiments show that errors appearing in the velocity estimation can be traced to (1) the near-field effect and (2) the influence caused by the transfer function of the receiver system, HR. The second factor also creates distinguishing changes between the source and receiver signals. In a two-receiver measurement system, the accurate travel time (velocity) can be identified by the cross correlation of the two receiver signals only if the near field is not pronounced and the two receivers possess very similar transfer functions. The near-field effect can be effectively avoided by placing the sensors at r1/λ ≥ 2 and r1/r2 ≥ 2, where r1 and r2=distances between the source and the first and second receivers, respectively, and λ=wavelength. In a one-receiver measurement system, the inherent time delay caused by the transfer function of the receiver system, HR, has to be quantified and corrected. The near-field effect also can be avoided by placing the receiver at least 2λ away from the source.     

Design and test of an electronic nose for monitoring the air quality in the international space station

Long-term manned space missions requires a continuous monitoring of the air quality inside the spacecraft. For this scope, among several different solutions, electronic noses have been considered. On behalf of European Space Agency an electronic nose specifically designed for air quality control in closed environment is under development. After several ground experiments concerning the monitoring of a biofilter efficiency, the instrument has been tested during the ENEIDE mission on board of the International Space Station. in this paper the instrument main concepts and its performance in ground and space experiments are illustrated.     

Assessment of MW-mile method for pricing transmission services: a negative flow-sharing approach

A negative flow-sharing approach to allocate transmission transaction charges among users of transmission services is proposed. The approach uses the properties of the MW-mile method but takes into account the economic benefits of both trading parties by analysing their shares in negative power flow or counterflow. This approach is incorporated with the justified distribution factor for power flow tracing purposes. Two case studies based on a 5-bus system and an IEEE 14-bus system are used to illustrate the proposed approach. The results show that the proposed approach has merit over the traditional MW-mile approaches in the context of revenue reconciliation of transmission services, regardless of transaction arrangements and locations. The profit-sharing concept introduced here provides a better economic signal in allocating charges for counterflows, which could benefit trading parties.     

Automatic EMI Measurement and Filter Design System for Telecom Power Supplies

Tests for compliance with conducted emission limits are usually carried out during the electrical product design process. Electromagnetic interference (EMI) filters are widely used for filtering excessive conducted emissions on a power cord. In this paper, a personal computer (PC)-based automatic EMI measurement and filter design system for telecom power supplies is proposed. The common-mode (CM) and differential-mode (DM) emissions in the live or the neutral line can be measured and recorded separately. The trial-and-error guesswork in selecting the filter components can be minimized by the proposed automatic filter design system. In other words, the EMI suppression effort is greatly reduced by the fast PC computing speed and the man-machine interface. The developed system can be an effective noise diagnosis and filter design tool for EMI engineers.     

Applicability of phase-locked loop to tracking the rhythmic activity in EEGS

Conventional methods of spectral analysis are based on mathematical or numerical algorithms applied to digitized signals. This paper discusses the applicability of the phase-locked loop (PLL) approach for tracking electroencephalogram (EEG) rhythmic bands (delta, theta, alpha, or beta). The use of the PLL for frequency tracking should also aid the development of online EEG interpretation and screening based on frequency characteristics when the PLL is realized by hardware. As a result, two factors in the applicability of the PLL are: (1) translation of the EEG spectrum to a higher-frequency band by a single-sideband (SSB) modulation scheme, and (2) the narrowband spectral feature of the EEG—a small difference between two major frequencies. The PLL output is further quantized according to the EEG rhythmic bands. Our analysis shows that the integrated system is capable of tracking the EEG rhythmic patterns.This work was supported by the National Science Council of Taiwan, Republic of China, under grant NSC87-2213-E-009-128.     

Magnetic Rotation in the A = 80 Region: M1 Bands in Heavy Rb Isotopes

We have studied the isotopes ⁸²Rb₄₅, ⁸³Rb₄₆, and ⁸⁴Rb₄₇ to search for magnetic rotation which is predicted in the tilted-axis cranking model for a certain mass region around A = 80. Excited states in these nuclei were populated via the reaction ¹¹B + ⁷⁶Ge with E = 50 MeV at the XTU tandem accelerator of the LNL Legnaro. Based on a γ-coincidence experiment using the spectrometer GASP we have found magnetic dipole bands in each studied nuclide. The regular M1 bands observed in the odd-odd nuclei ⁸²Rb and ⁸⁴Rb include B(M1)/B(E2) ratios decreasing smoothly with increasing spin in a range of 13⁻ ≤ J^π ≤ 16⁻. These bands are interpreted in the tilted-axis cranking model on the basis of four-quasiparticle configurations of the type π(fp)πg9/22νg9/2. This is the first evidence of magnetic rotation in the A ≈ 80 region. In contrast, the M1 sequences in the odd-even nucleus ⁸³Rb are not regular, and the B(M1)/B(E2) ratios show a pronounced staggering.     

Passive phase demodulation and laser-noise compensation scheme forfibre interferometers

A scheme for passive phase demodulation and laser intensity noise suppression for fibre interferometers is presented. The scheme uses a matched Ronchi grating filter to transform the interference fringe pattern formed between the reference and the signal fibres into intensity variation that can be related to the optical differential phase in the interferometer. By dividing the grating filter into four sectors with their fringe positions slightly shifted to introduce an equivalent of π/2 phase difference between the signals detected by individual sectors, one can apply cross-subtraction on diagonal sectors to remove intensity noise. In addition, the phase information due to the detected sample vibration can be recovered by taking the root-mean-square of the differential signals. The new scheme greatly reduces the complexity of practical fibre interferometers and an experimental setup has been implemented to demonstrate its expected merits     

Distributed-feedback dye-doped solgel silica lasers

Dye-doped solgel silica lasers with distributed feedback were demonstrated. Solgel silica slabs doped with Rhodamine 6G or Coumarin 460 dyes were fabricated. Periodic gain modulation in dye-doped solgel silica slabs were created by the interference pattern of the pumped laser beams diffracted by a holographic grating. Laser pulse trains with subnanosecond spikes were induced. Laser emission wavelengths were centered at 480 and 585 nm for Rhodamine 6G and Coumarin 460, respectively. It was possible for us to tune approximately 20 nm around the emission centers by varying the intersection angle. The laser linewidth was of the order of 60 pm.