This paper demonstrates a 10-bit low-power lowcomplexity successive approximation register analog-to- digital converter (SAR ADC) suitable for biomedical applications. The architecture of the proposed SAR ADC includes a low-distortion CMOS bootstrap sample and hold (S/H) switch, a pair of PMOS with double-tail single-ended dynamic latch comparator, a bridge binary weighted capacitor array digital to analog converter (DAC) with an efficient-energy switching scheme, and a modified successive approximation register (SAR) controller logic. The proposed converter is implemented using TSMC 65nm CMOS technology, 1.2 V supply voltage with a sampling rate of 500 KS/s. According to the post-simulation results, the proposed SAR ADC consumes 3.353 mu W and achieves a spurious-free dynamic range (SFDR) of 59.4 dB without supplementary calibration. The ADC core occupies an active area of 0.007 mm(2) with a figure of merit (FoM) of 15.8 fj/conv.step.

This study investigates the potential of Cesium−formamidinium-based (CsyFA1−yPb(IxBr1−x)3) perovskite materials as promising candidates for efficient and stable perovskite solar cells (PSCs), that can be tailored for indoor applications. These materials offer the unique advantage of simultaneously stabilizing photoactive compositional phase transitions and enhancing thermal stability, making them well-suited for indoor environments. The optical band gaps of Cesium−formamidinium, ranging from 1.5 to 1.8 eV, can be engineered to align with the spectrum of light sources commonly used indoors. Therefore, this study directs into the design and simulation of Cesium-Formamidinium-Based PSCs, with a specific emphasis on optimizing their performance under indoor LED illumination. Parameter manipulation related to the Hole Transport Layer (HTL) and Electron Transport Layer (ETL) is utilized to establish optimal band alignment in order to reduce recombination losses and boost power conversion efficiency. A co-design approach between the ETL and HTL is introduced, enabling precise engineering of interfaces, and optimizing charge transport and collection efficiency. This research presents an optimal design with a conduction band minimum (VBM) energy level of 4.05 eV for the ETL and a valence band maximum (VBM) energy level of 5.15 eV for the HTL, resulting in a power conversion efficiency (PCE) of 25.00

Double-junction solar devices featuring wide-bandgap and narrow-bandgap sub-cells are capable of boosting performance and efficiency compared to single-junction photovoltaic (PV) technologies. To achieve the best performance of a double-junction device, careful selection and optimization of each sub-cell is crucial. This work presents the investigation of an all-thin-film two-terminal (2T) monolithic homojunction perovskite (PVK)/c-Si tandem cell using Silvaco TCAD simulation. The front sub-cell utilizes homojunction PVK that has a bandgap of 1.72 eV, whereas the rear sub-cell uses thin c-Si with a bandgap of 1.12 eV. Both cells are connected via a p ++ / n ++ silicon tunnel diode. Experimental calibration of the heterojunction PVK and c-Si cells yields power conversion efficiencies (PCE) of 18.106% and 17.416%, respectively. When integrated into an initial PVK/c-Si tandem, the resulting cell achieves a PCE of 29.38%. To compare the performance, the heterojunction PVK layer is replaced with an n-p homojunction PVK layer, revealing the impact of the absence of a surplus built-in electric field in the perovskite film as a strong limiting factor. Further, a thorough investigation of four distinct structures for the n-p homojunction PVK cell is conducted. The four structures include a complete cell, electron transport layer (ETL)-free, hole transport layer (HTL)-free, and carrier transport layer (CTL)-free structures. The results show that the CTL-free structure has significant potential after applying certain optimization techniques that result in reducing surface recombination, enhancing the built-in electric field, and improving light absorption. With the current-matching condition achieved, the tandem efficiency reaches 36.37%.

Beamforming represents a pivotal technology in massive multiple-input multiple-output (MIMO) systems, as it facilitates the regulation of transmission and reception operations. Beamforming techniques’ categorization is based either on their hardware architecture or implementation strategy. This paper proposes an orthogonal beamforming technology founded on a specific implementation method that utilizes predetermined orthogonal beams to serve users. The suggested approach incorporates numerous orthogonal beams relying on a substantial number of antennas at the base station. The primary objective of this approach is to enhance the performance of massive MIMO systems by augmenting spectral efficiency and accommodating more users. The proposed beamforming approach is well suited for millimeter frequency bands. The purpose of this paper is to explore the suggested orthogonal beamforming technology. The concept of this approach is described at first and then followed by an evaluation of its efficacy for a single user through the allocation of orthogonal beams. The suggested approach is also examined in the context of multiuser systems, and the results are compared with the adaptive ZF beamforming technique. Furthermore, the paper presents solutions to the issues that may arise in multiuser systems, for example, ensuring that each orthogonal beam is assigned to only one user. The simulations conducted in this study demonstrate that the suggested approach outperforms the ZF technique in terms of both the spectral efficiency and the number of serviced users. Specifically, the suggested approach can enhance SE by approximately 40.6% over the ZF technique, and it can support up to double the number of users when compared to the ZF approach.

Multi-junction solar cells exhibit superior power conversion efficiency (PCE) in comparison with their single-junction counterparts. The tunable bandgap, low-cost, elevated short circuit current density (Jsc), and open-circuit voltage (Voc) of perovskite solar cells (PSCs) have led to their widespread adoption as top sub-cells in tandem devices. Stability remains a significant challenge for these cells. To address this issue, carbon perovskite solar cells (CPSCs) have emerged as a potential solution, offering enhanced stability without hole transport layers (HTLs). This study focuses on the simulation of HTL-free CPSCs using an improved electron transport material (ETM) instead of TiO2. The implementation of this enhancement leads to a notable increase in the PCE of the CPSCs, rising from 7.97 % to 14.38 %. Through optimizing the defect concentration and doping density of the perovskite absorber layer, a significant improvement in the PCE is achieved, reaching 16.87 %. A novel configuration incorporating a gradient doping profile in the perovskite layer is introduced, leading to a remarkable enhancement in the PCE, which reaches 22.22 %. Two absorber materials are suggested, CIGS and GeTe, as bottom sub-cells. Three tandem cell configurations, PSC/CIGS, CPSC/CIGS, and CPSC/GeTe, are rigorously explored based on the optimized sub-cells. The PCEs of the proposed configurations are found to be 30.52 %, 22.7 %, and 36.59 %, respectively. Computational analysis reveals that the PSC/CIGS tandem cell exhibits lower stability against temperature variations compared to CPSC/CIGS and CPSC/GeTe. Additionally, the proposed CPSC/GeTe tandem is highly praised as a favorable contender, offering both high efficiency and stability among the various configurations considered in this study.

This work sheds light on the potential of Cadmium Selenide (CdSe) solar cells for indoor applications. CdSe boasts a wide direct bandgap, high carrier mobility, and a high absorption coefficient, making it an attractive candidate for harnessing ambient indoor light. Our study centers around an experimental solar cell architecture composed of FTO/CdSe/PEDOT:PSS/CuI/ITO, which exhibits a power conversion efficiency (PCE) of 6.00 %. Through a meticulous analysis of the core technological aspects of this cell, we successfully replicate the measured current-voltage characteristics and other experimental data, affirming the validity of our simulation modeling approach. Moving forward, we delve into the design and optimization of CdSe-based solar cells under white LED illumination. We emphasize the pivotal role of a double-hole transport layer (HTL) configuration over a single HTL, with a focus on optimizing the alignment between the HTL/back contact and HTL/absorber interfaces. The strategic incorporation of a heavily doped p-type HTL material, boasting both a deep valence band maximum (VBM) and a shallow conduction band minimum (CBM), is identified as paramount, especially for a deep VBM absorber like CdSe. Adding double HTL materials also facilitates efficient hole collection within the CdSe thin film while mitigating undesirable electron-hole recombination at the critical interface between the hole collection layer and the electrode. The implementation of a double HTL configuration based on CuI/ZnTe:Cu or CuI/BCS significantly enhances performance, resulting in a PCE in the order of 20 % under 200 lux and 2900 K LED illumination. Moreover, we introduce the single HTL design to provide other alternatives for efficiency boosting. Upon increasing the work function of the front contact, it is found that the valence band offset between the HTL and the absorber can be engineered, resulting in a PCE above 21.5 %.

Random Access Memory (RAM) cells find extensive applications in diverse digital electronic systems. In the realm of Static Random Access Memory (SRAM) cells, minimizing power consumption presents a formidable challenge, particularly in the context of ultra-low-power applications like implanted biomedical devices. Traditionally, the reduction of power consumption in Com-plementary Metal-Oxide-Semiconductor (CMOS) SRAM cells involves scaling down the supply voltage. However, this approach necessitates a concurrent scale-down of the process technology, impacting the read and write stability of the system. This research introduces a novel and expedient SRAM cell design comprising four transistors and four memristors (4T4M). Comparative analysis against conventional 6T and 4T2M SRAM cells demonstrates that the proposed 4T4M SRAM cell exhibits superior performance in terms of both power consumption and delay. All SRAM cells were meticulously modeled and simulated using 130nm technology in Cadence Virtuoso. The results indicate that the proposed 4T4M SRAM cell boasts a noteworthy reduction of 11.56% and 62% in power consumption when juxtaposed with 4T2M and 6T SRAM cells, respectively. Additionally, it demonstrates a faster response time, outperforming 4T2M and 6T SRAM cells by 10.5% and 57.5%, respectively.

Utilizing multi-junction solar cells is one of the recent approaches to meet the energy demand. Due to the unique set of perovskite optical and electrical behavior, perovskite solar cells (PSCs) are progressively attracting the researchers' attention. This paper proposes a multi-junction cell with CIGS-GeTe as the bottom cell's twin-layered absorbers, while the top cell is comprised of a conventional PSC. The simulation results reveal that this promising tandem perovskite/CIGS-GeTe structure shows a power conversion efficiency (PCE) of 35.86%, with a high open-circuit voltage (Voc) of 2.01 V.

The coexistence of mixed numerologies with OFDM introduces significant inter-numerology interference (INI) due to high out-of-band emission (OOBE). This interference worsens with increasing offset between numerologies, negatively impacting system performance. To address this issue, this paper proposes the use of a Hybrid Waveforms (HW) technique to mitigate the effects of INI in mixed-numerology systems. Specifically, f-OFDM, UFMC, and WOLA waveforms are employed instead of OFDM to suppress OOBE for users with higher numerology. The effectiveness of the proposed technique is evaluated using the Vienna 5G link-level simulator. Simulation results demonstrate that utilizing f-OFDM, UFMC, and WOLA waveforms for higher numerology users is more efficient in reducing INI compared to OFDM. By implementing the proposed framework, user throughput increases and Bit Error Rate (BER) decreases. Among the hybrid waveforms, f-OFDM proves to be the most effective, providing the highest throughput and the lowest BER when compared to UFMC, WOLA, and OFDM. For instance, in the case of f-OFDM, when the power of the second user is ten times that of the first user, the user BER in the uplink can be reduced by 63.3%, and its throughput can be increased by 47.3%. Similarly, in the downlink, the user BER can be reduced by 60.9%, and its throughput can be increased by 43%. These improvements are observed when comparing against the traditional system (OFDM), where the first user uses a subcarrier spacing of 15 kHz and the second user uses a 60 kHz spacing with a 180 kHz guard band.

Radar systems are an interesting application of SDR due to SDR’s low cost and high configurability compared to traditional radar systems. During this research, a complete SDR system was designed and implemented targeting radar applications. The component used in this design were chosen carefully to afford a wide operating range, high speed, low power dissipation, small size, low cost, configurability, low noise, and good performance. The implemented SDR can transmit and receive signals up to 6.8 GHz with 100 MHz instantaneous bandwidth. The system’s small size and good performance suit portable UAVs, SAR, and imaging radars. This research used the implemented SDR as an FMCW radar system capable of detecting motion behind numerous barriers by employing an FPGA as a real-time signal processor. The proposed UWB FMCW radar can penetrate walls and provide exact range resolution to overcome any masking concerns that may develop during detection. With a range of 25m, a resolution of 20cm, and a transmitter power of 16 mW, the proposed radar could effectively give the range profile of a moving person around a room and behind one or two brick walls.

High-efficiency solar cells with low manufacturing costs have been recently accomplished utilizing different technologies. III-V-based tandem solar cells have exhibited performance enhancement with a recent efficiency of greater than 39% under AM1.5G and 47% under concentration. Integration of such III-V materials on a relatively cheap Silicon (Si) substrate is a potential pathway to fabricate high-efficient low-cost tandem solar cells. Besides, perovskite solar cells, as third-generation thin film photovoltaics (PV), have been meteorically developed at a reasonable cost. At present, there are still questions for cost reduction of perovskite materials and solar cell modules because of their limited commercialization. In this review, stacking Si solar cells with III-V material to form Si-based III-V tandem solar cells is presented with different integration technological routes. Also, perovskite/Si tandem solar cells have been reviewed alongside their main engineering challenges introduced through the fabrication of perovskite-based tandem solar cells. Finally, a comparison between III-V tandem solar cells, Si-based III-V tandem solar cells, and perovskite-based tandem solar cells is introduced so that the best technology for a specific application could be determined. The review provides a comprehensive study of two different technologies (III/V and Perovskite) to demonstrate the most valuable cost reduction availability for each.

Medical images rather than any other types of images need high storage space. The lack of storage facilities, especially in developing countries, encourages researchers to find solutions for this problem. Compression of medical images is a priority, although it leads to some loss in the stored images. This paper introduces a framework for medical image storage and retrieval for the purpose of diagnosis. This framework adopts decimation as a tool for image compression, while interpolation is used as a tool for further image reconstruction. The quality of the reconstructed images is evaluated with a scale-invariant feature transform (SIFT)-based technique. Another task involved in this paper is the automatic diagnosis from the reconstructed images based on deep learning. Different types of interpolation algorithms are investigated and compared in this framework for the process of medical image reconstruction.

An efficient and linear power amplifier (PA) for millimeter wave applications using a 130nm CMOS process is presented in this paper. The proposed PA uses transformer coupling for output, inter-stage, and input matching and also utilizes inter-stage inductors to boost RF achievement. The Ansoft high-frequency structure simulator (HFSS) is used to analyze and design the coupling transformers and inter-stage matching inductors to achieve a high coupling coefficient and quality factor over the frequency range of 19 to 29 GHz. The 2 harmonic termination networks are connected at each stage of the proposed power amplifier to enhance the gain and efficiency. The suggested radio frequency power amplifier consists of three stages, the input stage operates in class-B operation to increase the efficiency without an influence on the DC power consumption, while the driver and power stages work in class-AB to improve the RF output power. Also, the power stage is a parallel combination of class-B and class-AB to improve the one-dB compression point and enhance the linearity. The proposed RF power amplifier operates in the frequency range from 19 to 29 GHz. The suggested PA achieves a saturated output power of 15.1 dBm, a maximum power added efficiency (PAE) of 19.35 %, and a peak power gain of 22.72 dB. Moreover, the peak output 1-dB compression point for the proposed power amplifier is 13.1 dBm and consumes a DC power of 98.09 mW. Lastly, the die and overall areas of the suggested power amplifier are 0.4 mm and 0.67 mm , respectively.

The primary purpose of recent research on solar cells is to achieve a higher power conversion efficiency with stable characteristics. To push the developments of photovoltaic (PV) technology, tandem solar cells are being intensively researched, as they have higher power conversion efficiency (PCE) than single-junction cells. Perovskite solar cells (PSCs) are recently used as a top cell of tandem solar cells thanks to their tunable energy gap, high short circuit current, and low cost of fabrication. One of the main challenges in PSCs cells is the stability issue. Carbon perovskite solar cells (CPSCs) without a hole transport material (HTM) presented a promising solution for PSCs’ stability. The two-terminal monolithic tandem solar cells demonstrate the commercial tandem cells market. Consequently, all the proposed tandem solar cells in this paper are equivalent to two-terminal monolithic tandem devices. In this work, two two-terminal tandem solar cells are proposed and investigated using the SCAPS-1D device simulator. Carbon perovskite solar cell (CPSC) without hole transport material (HTM) is used as the top cell with a new proposed gradient doping in the perovskite layer. This proposal has led to a substantial enhancement of the stability issue known to be present in carbon perovskite cells. Moreover, a higher PCE, exceeding 22%, has been attained for the proposed CPSC. Two bottom cells are examined, Si and CIGS-GeTe solar cells. The suggested CPSC/Si and CPSC/CIGS-GeTe tandem solar cells have the advantage of having just two junctions, which reduces the complexity and cost of solar cells. The performance parameters are found to be improved. In specific, the PCEs of the two proposed cells are 19.89% and 24.69%, respectively.

Institutions have been adopting work/study-from-home programs since the pandemic began. They primarily utilise Voice over Internet Protocol (VoIP) software to perform online meetings. This research introduces a new method to enhance VoIP calls experience using deep learning. In this paper, integration between two existing techniques, Speaker Separation and Speaker Identification (SSI), is performed using deep learning methods with effective results as introduced by state-of-the-art research. This integration is applied to VoIP system application. The voice signal is introduced to the speaker separation and identification system to be separated; then, the “main speaker voice” is identified and verified rather than any other human or non-human voices around the main speaker. Then, only this main speaker voice is sent over IP to continue the call process. Currently, the online call system depends on noise cancellation and call quality enhancement. However, this does not address multiple human voices over the call. Filters used in the call process only remove the noise and the interference (de-noising speech) from the speech signal. The presented system is tested with up to four mixed human voices. This system separates only the main speaker voice and processes it prior to the transmission over VoIP call. This paper illustrates the algorithm technologies integration using DNN, and voice signal processing advantages and challenges, in addition to the importance of computing power for real-time applications.

Although most people can communicate effectively through speech, some have difficulties doing so due to physical or mental impairments. Communication is a significant obstacle for individuals with these disabilities. Methods of deep learning can aid in the elimination of communication barriers. This article proposes a model based on deep learning for detecting and recognizing words from gestures. Deep learning models such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) are used to recognize signs from Egyptian Sign Language (ESL) video frames. There are many activation functions, and every type has advantages and disadvantages. All these activation functions were applied to our dataset for ESL. To overcome the main disadvantage of the Relu activation function, we proposed a gesture recognition method for ESL using Mediapipe and modified GRU with a new activation function (Talu). The proposed model achieves approximately 94.95% accuracy across ten different signs. This method may assist people unfamiliar with Egyptian sign language in communicating with people with speech or hearing impairments.

With the aim of achieving high efficiency, cost-effectiveness, and reliability of solar cells, several technologies have been studied. Recently, emerging materials have appeared to replace Si-based cells, seeking economic fabrication of solar cells. Thin-film solar cells (TFSCs) are considered strong candidates for this mission, specifically perovskite-based solar cells, reporting competitive power convergence efficiencies reaching up to 25.7%. Substantial efforts have been invested in experimental and research work to surpass the Si-based cells performance. Simulation analysis is a major tool in achieving this target by detecting design problems and providing possible solutions. Usually, a TFSC adopts p-i-n heterojunction architecture by employing carrier transport materials along with the absorber material in order to extract the photogenerated electrons and holes by realizing a built-in electric field. Eventually, this dependency of conventional heterojunction TFSCs on carrier transport layers results in cost-ineffective cells and increases the possibility of device instability and interface problems. Thus, the design of p-n homojunction TFSCs is highly desirable as an essential direction of structural innovation to realize efficient solar cell operation. In this review, a summary of the fundamentals of TFSC materials, recent design and technology progress, and methodologies for improving the device performance using experimental research studies will be discussed. Further, simulation analysis will be provided by demonstrating the latest research work outcomes, highlighting the major achievements and the most common challenges facing thin film homojunction solar cell structures and the methods to improve them.

Recently, nanowire detectors have been attracting increasing interest thanks to their advantages of high resolution and gain. The potential of using nanowire detectors is investigated in this work by developing a physically based model for Indium Phosphide (InP) phototransistor as well as by performing TCAD simulations. The model is based on solving the basic semiconductor equations for bipolar transistors and considering the effects of charge distribution on the bulk and on the surface. The developed model also takes into consideration the impact of surface traps, which are induced by photogenerated carriers situated at the surface of the nanowire. Further, photogating phenomena and photodoping are also included. Moreover, displacement damage (DD) is also investigated; an issue arises when the detector is exposed to repeated doses. The presented analytical model can predict the current produced from the incident X-ray beam at various energies. The calculation of the gain of the presented nanowire carefully considers the different governing effects at several values of energies as well as biasing voltage and doping. The proposed model is built in MATLAB, and the validity check of the model results is achieved using SILVACO TCAD device simulation. Comparisons between the proposed model results and SILVACO TCAD device simulation are provided and show good agreement.

Accurate PV system simulators are implemented with expensive software platforms using paid irradiance data. The main purpose of this paper is to develop and validate a PV system simulator, beginning with a solar cell parameter extraction model, then test and validate long-term Irradiance data using free online source (Typical Meteorological Year TMY in (PVGIS) European website), and finally building full solar generator simulator to run in working real conditions. Comparing results with Accurate Paid PV simulators (which use the Muneer model) showed good accuracy of the proposed simulator. Work flow starts with the Irradiance model’s data processing, then solar cell 5 parameters model data processing (to extract cell parameters), and finally full system simulator. MATLAB coding programs in real working conditions are used for simulation. Results of solar cell parameter extraction show 99.6% to 99.99% matching with data sheet and cell performance under standard test conditions. System model simulation output shows 8% less yearly generated energy compared to the PVGIS 2022 long-term simulation (hourly basis (one-year time)). This is due to incident energy variations (between the years 2016 and 2022) of 4.02%. The novelty of the algorithm is the methodology, as it tests irradiance data on an hourly basis and validates results for a whole continuous year. Also, the 5-parameter solar cell model is used to be validated in long term analysis, not only STC conditions and could be applied on any PV solar cell. The algorithm and block diagram used are scalable, modular, and interchangeable with similar models to be tested. This simulator could test several methods and models in solar pv technology.

The long-term performance of traditional solar panels can be affected by various climate conditions, resulting in issues such as decreased power output, interconnector failure, and cell fracture. Unfortunately, traditional modules are not repairable, and often the entire unit must be replaced, even if the failure is due only to a single component. In this work, conventional encapsulation methods are investigated, and a novel solar panel design approach is introduced. This innovative approach enables easy and direct access to individual components, thereby enabling the convenient carrying out of repairs, upgrades, and modifications. The proposed module configuration is composed of a double-layer structure. The initial layer functions as a protective glass cover while the second layer is made up of solar cells that are attached to a printed circuit board (PCB) that can endure high temperatures. These two layers are combined within an aluminum frame that can be opened for accessibility. To test the effectiveness of this new encapsulation technique, an experimental study was conducted. It was revealed through this experimental study that the dark and illuminated current–voltage characteristics are not affected when applying the new encapsulation technique. Furthermore, a theoretical thermal analysis was conducted in order to compare the performance of the proposed module with that of a conventional module. According to the thermal analysis, the proposed encapsulation method should result in slightly higher thermal stress on the solar cells compared with conventional encapsulation. Nonetheless, the proposed methodology offers advantages in terms of reliability and reparability. Thus, implementing the presented design can help conserve natural resources and reduce production costs.