Electronics and Communication Engineering

Abstrat-An analog technique for correcting baseline offset and drift in low-frequency systems is analyzed. The described method applies to periodic and nearly periodic signals, characterized by a time interval in which they may be considered at rest (electrocardiogram (ECG) signals, for instance), and is limited to linear drifts. Two different circuits have been developed and are discussed here. Signal conditioning performed on suitable input waveforms is presented. Noise effects have been theoretically considered and experimentally evaluated.

A delineation process for micrometer size lateral patterns of negative photoresist, on polished silicon surfaces carrying vertical trenches of V-shape and depth in the range of 100-200 micrometers, has been developed by integrating a compatible positive photoresist (S1813) lithography employing single photo mask. Arrays of V-groove patterns of 150 micrometer depth have been delineated with HNR120 photoresist on (100) silicon surfaces for further selective electroplating of metals. The optimized process is compatible with conventional IC process and is cost effective in realizing V-groove inductors for high frequency applications.

In this article, new feature descriptor local bit plane adjacent neighborhood dissimilarity pattern (LBPANDP) is introduced for CT image retrieval. In the proposed method, the input image is first decomposed into eight binary bit planes. Then in each of the first four most significant bit planes, for each center pixel, the dissimilarity information of its binary neighbors are encoded into a single value. The encoded values of each bit plane is then compared with the intensity of the center pixel and this relationship is finally encoded to devise the LBPANDP descriptor. The proposed descriptor is highly discriminative and considers only the first four most significant bit planes for encoding, which greatly reduces the dimension of the feature vector. Retrieval performance of LBPANDP is investigated on two CT image databases and the results show a significant improvement in retrieval efficiency by LBPANDPover many recent techniques.

Face image retrieval is considered as an active research field in computer vision. This paper describes a novel feature descriptor called elliptical local binary co-occurrence pattern (ELBCoP) for face image retrieval. This descriptor employs a combination of sparse elliptical local binary pattern (ELBP) and grey level co-occurrence matrix (GLCM). Unlike previous approaches, the sparse ELBP consider only 4 horizontal and 4 vertical neighbors from the elliptic shaped neighborhood, and uses 4 simple diagonal neighbors. Then the co-occurrence of pixel pairs, in the three local pattern maps obtained using sparse ELBP, are calculated using GLCM in two selected directions. These two directions of GLCM are selected according to the shape of the elliptic neighborhood. Through GLCM, the proposed ELBCoP extracts the frequency details and also the spatial relationship between the local pattern pairs very effectively. It is also shown that a properly selected subset of ELBCoP can still provide a robust and efficient description of face images, with significant reduction in feature vector dimensions. Experimental results on two benchmark face image databases show superior retrieval performance of ELBCoP and also subset of ELBCoP, when compared to various state of the art methods including a few very recent ones.

Reliability has been one of the major concerns for AlGaN/GaN high-electronmobility transistors (HEMTs) over the past decades owing to their high-power operation. Although significant progress has been made in recent years, to position AlGaN/GaN HEMT technology as a disruptive technology, better understanding of reliability phenomena and their enhancement is necessary. Greater strength of physical phenomena such as converse piezoelectric strain, electric field, electron temperature, and Joule heating accelerates the degradation and reduces the lifespan of such devices. A detailed numerical study has been carried out to observe the impact of gate filleting on the performance of a AlGaN/GaN HEMT. It is observed that the converse piezoelectric strain in the AlGaN barrier layer, as well as the electron and lattice temperatures are suppressed due to the filleting of the gate geometry. To understand this more deeply, a comparison is drawn between field-plate rectangular-gate HEMTs and filleted-gate HEMTs with and without a field plate. For the filleted-gate HEMTs with and without a field plate, the electric field and converse piezoelectric strain are lower by 38% and 30%, respectively, as compared with the rectangular-gate HEMT with a field plate. As the filleting radius is increased, the gate leakage current and lattice temperature at the gate/AlGaN interface are reduced and the OFF-state reliability is enhanced, together with a reduction in the converse piezoelectric strain and electron temperature. Based on the presented analysis, a filleted-gate HEMT is proposed as a potential candidate to mitigate damage induced by converse piezoelectric strain, electron temperature, and Joule heating in future AlGaN/GaN-based high-power devices.

Reliability enhancement of AlGaN / GaN HEMT is a significant thrust area due to rapidly improving material and processing technology. In this paper, a detailed analysis of gate-shaped AlGaN / GaN HEMT with field plate is presented. Although AlGaN / GaN HEMT with field-plate is well known, its blending with gate-shaping leading to a more robust and reliable behaviour is described in this paper. It is observed that the threshold voltage and transconductance invariably remain constant for various combinations of gate-shaped and field plate placements. The threshold voltage for all the devices are found to be-5.8 V. The peak transconductance for the devices without field plate and with field plate is ∼ 0.16 S/mm and ∼ 0.15 S/mm, respectively. Apart from leakage current, the electric field also gets mitigated for both gate-shaped and field-plated devices by ∼ 45% and ∼ 68%, respectively. The moderation in electric field further assists in the reduction of electron temperature for gate-shaped and field-plated structures by ∼ 12% and ∼ 85%, respectively. Additionally, breakdown voltage increases for the gate-shaped devices to 133 V as compared to 120 V of conventional devices without field plate. Significant reduction in leakage current, electric field, and electron temperature is accompanied by a minor increment in capacitance for the field-plated structure, hence, the proposed structure is expected to enhance reliability of the device. Thus, it is anticipated that the proposed devices with enhanced reliability would be a step ahead of conventional devices and would find major applications in high power domain. INDEX TERMS Capacitance voltage (CV), electron temperature, GaN HEMT, gate shape, leakage current.

The worsening energy crisis, growing environmental consciousness, and the detrimental consequences of climate change, prompted governments to reduce carbon footprints. One of the approaches involved is adopting green energy technology to charge electric vehicles (EVs). The US Department of Energy estimates that EVs may effectively use 60% of the input energy while driving, twice as much as traditional fossil fuel-based vehicles. Although EVs are tremendously efficient, the amount of greenhouse gas emissions they can reduce relies on the source of electricity needed to power them. To summarize the role of RE as a viable charging alternative, in this study, we analyze four essential elements of EV charging infrastructure, RE-enabled smart charging approaches, utility interest and associated challenges and opportunities. First, the existing RE sources employed for EV charging are discussed with their global adoption, advantages and drawbacks and the leading countries. Second, we presented a thorough investigation of energy storage technologies, charging systems, related power electronics, and smart grid integration to facilitate the adoption of RE in EVs. Third, we discussed in-depth the many industry-implemented smart charging approaches with RE in light of the most recent global trend in EV energy usage. Finally, given the inherent challenges associated with realizing the sustainable transition, we discuss the technological challenges and opportunities related to grid integration, renovation, standardization, maintenance, network security and resource optimization. The authors believe this manuscript will serve as an information cornerstone for all the involved parties and scientific communication to gain a deeper understanding and contribute.