Front-end System Research Articles

A Miniaturized Multiband Antenna with Frequency Reconfiguration for 5G and IoT Applications

This research focuses on designing and testing a compact, multiband antenna that can switch between different frequency bands using a PIN diode. The demonstrated antenna is constructed on a 1.6 mm thick FR4 substrate and features a ground plane on the rear side. Because of its small dimensions (24 mm x 19 mm × 1.6 mm), it can be effortlessly incorporated into various kinds of RF front-end systems. The antenna presented is capable of achieving hexa/Triple band characteristics through the utilization of a PIN diode positioned between the metal strip and the F shaped monopole. The examined antenna is capable of operating in L and C bands across a range of six different frequencies when the PIN diode is inactive: 2.54 GHz, 2.64 GHz, 3.48 GHz, 4.3 GHz, 5.25 GHz, and 5.68 GHz supporting 5G and IOT services. Conversely, with the PIN diode activated, it functions in C-band across three specific frequencies: 4.3 GHz, 5.2 GHz, and 5.68 GHz supporting IOT services. The investigated antenna exhibits very small frequency ratios between two consecutive bands of the value of 1.04/1.3/1.23/1.22/1.08, respectively. The investigated design is fabricated and results of the design under investigation were compared, showing a strong correlation between the simulated and measured data.

High-contrast front end based on Yb: YAG solid-state laser for PW-level Ti: sapphire laser.

In this paper, we demonstrate a high-contrast front-end laser system based on Yb: YAG solid-state laser for Ti: sapphire terminal amplification. An ultrafast Yb: YAG solid-state laser is used to generate a broad-spectrum seed through white light generation (WLG), and then the signal light near 1600 nm is amplified by three-level colinear optical parametric chirped pulse amplification (OPCPA). Finally, a fs second harmonic generation (SHG) is used to obtain a laser output with a central wavelength of 795 nm, a pulse width of 40.2 fs, a contrast baseline of nearly 10-12 within 1 ns, and almost no ps pedestal. We used this laser system as a seed to amplify it to about the theoretical estimated 30 TW level, showing good dispersion properties and contrast preservation capabilities.

AI-Based Energy Management and Prediction System for Smart Cities

In recent years, there has been an increasing interest in smart city concepts in response to a growing demand for more sustainable and efficient urban spaces. In this paper, an in-depth exploration of load forecasting in an innovative city framework is carried out through the building of a software application with a graphical user interface (GUI) and prediction using long short-term memory (LSTM). To fulfill their role in enabling intelligent cities, accurate load forecasting is needed to enable energy management, reduce peak demand, and allow for well-informed decisions and energy distribution optimization. Specifically, in this work, we consider the application of LSTM to load forecasting systems within the context of a smart city. Since LSTM has a high capability in capturing complicated temporal structures, it is indeed an efficient approach to load forecasting, especially considering long-term dependencies. We focus on the strength of LSTM in comparison with the traditional statistical analysis and other machine learning techniques, most notably, LSTM’s ability to handle nonlinear and dynamic load behavior typical in innovative city energy systems. The GUI is the system's front end where the user enters the data, and at this point, we have the city officials, energy managers, and the community people and get their customized load forecast. The discussion of the outcomes of the experiment with the cross-platform GUI application and the improved LSTM forecasting model is given. Based on the evaluation of the model in terms of accuracy and performance, the research is done in an accepted manner to predict the complex load pattern in a smart city environment by proving the efficiency of the LSTM model. The effectiveness of different decisions in various cases is evaluated to consider the influence on decision-making processes and energy optimization; various cases demonstrate how the proposed GUI application is helpful in facilitating better management of energy. This research will, therefore, endeavor to create knowledge in the area of energy management to foster the development of effective intelligent cities.

Biological metasurfaces based on tailored Luria Bertani Agar growth medium formulations for photonic applications.

Biodegradablealternatives to classic solid-state components are rapidly taking place in front-end photonic systems like metamaterials, meta-surfaces and photonic crystals. From this point of view, numerous solutions have been proposed involving eco-friendly compounds. Among them, the Luria Bertani agar (LBA) growth medium has been recently proposed as a functional option with the remarkable advantage of allowing the growth of fluorescent protein expressing bacteria. Such a possibility promises to lead to development of a new generation of biological and eco-sustainable optical sources based on meta-surfaces. There is, however, still a main drawback to address, related to the highly scattering nature of these compounds. To ensure adequate nutritive elements for cell growth, LBA hosts several compounds like NaCl, yeast extracts and tryptone. The presence of these components leads to very scattering LBA films, thus hindering its performance as an optical polymer. A trade-off arises between nutritive capacity and optical performance. In this paper, we successfully address this trade-off, demonstrating that a reduction of the basic nutrients (net Agar concentration) of LBA largely enhances the optical properties of the film as a photonic polymer without compromising its cell-viability. We considered two new LBA formulations with two- (LB2A) and four-fold (LB4A) reduction of the nutrients and replicated a square-lattice meta-surface used as a benchmark architecture. We demonstrated that both the replica molding performances and the optical properties (absorption, scattering and diffraction efficiency) of LBA formulations increase with decreasing nutrient concentration, without losing their cell-growth capability. To demonstrate this fundamental aspect, we inoculated the most critical case of LB4A with green-fluorescent-protein-expressing E. coli bacteria, verifying both their vitality and good photoluminescence properties. These results overcome one of the main limitations of LBA as a functional biopolymer for optical applications, unlocking its use in a new generation of biological quantum optical frameworks for all-biological weak and strong light-matter interactions.

MRI retrospective respiratory gating and cardiac sensing by CW Doppler radar: A feasibility study.

This study investigates the feasibility of non-contact retrospective respiratory gating and cardiac sensing using continuous wave Doppler radar deployed in an MRI system. The proposed technique can complement existing sensors which are difficult to apply for certain patient populations. We leverage a software-defined radio for continuous wave radar at 2.4 GHz to detect in-vivo respiratory and cardiac timescrolled signals. In-bore radar signal demodulation is verified with full electromagnetic simulations, and its functionality is validated on a test bench and within the MR bore with four normal subjects. Radar sensing was compared against well-known references: electrocardiography on a test bench, system bellows, and pulsed plethysmography sensors with in the MRI bore. The feasibility of noncontact cardiac rate sensing, dynamic breathing sequence synchronization, and in-bore motion correction for retrospective respiratory gating applications was demonstrated. Optimal radar front-end system arrangement, along with spectral isolation and narrow bandwidth of operation, enable MRI-compatible and interference-free motion sensing. The signal-to-noise-ratio degradation by the radar integration was within 4.5% on phantom images. We confirmed that in-bore retrospective motion correction using CW Doppler radar is feasible without MRI system constraints. Non-contact motion correction sensing in MRI may provide better patient handling and through put by complementing existing system sensors and motion correction algorithms.

Analysis and optimization of whine noise in the front-end gear train

This paper focuses on the gear whine noise problem of this engine, analyses it from two aspects of excitation source and transmission path, and puts forward the corresponding optimization method in combination with the actual product, which mainly includes the enhancement of the intrinsic frequency of the engine assembly, the optimization of the gear macro-parameters and the optimization of the gear micro-parameters. The optimization scheme achieves the objectives of minimizing transmission error and optimizing gear contact surface pressure and improves the NVH performance of the gear while considering the reliability of the gear system. Finally, the feasibility of the optimization scheme is verified by engine noise bench test. The study's results offer valuable insights for the design of diesel engine front-end gear systems, providing an effective approach to address existing product issues and to guide the development of new products.

Little iLocater: paving the way for iLocater

ABSTRACT Diffraction-limited radial-velocity instruments offer a pathway towards improved precision and stability, and the exploration of new parameter spaces at high spatial and spectral resolution. However, achieving the necessary performance requires careful instrument design and considerable on-sky testing. We describe the design and construction of ‘Little iLocater’ (Lili), a compact spectrograph that has been used to validate the performance of the front-end fibre-injection system of the iLocater spectrograph. We present the design, assembly, and performance using on-sky data obtained at the Large Binocular Telescope (LBT), including extraction of spectra from standard stars, testing of the atmospheric dispersion corrector to elevations of 40°, and spatially resolved spectra from close companion systems. These results show the front-end fibre-injection system is performing as expected and is indicative of iLocater’s capabilities once installed at the LBT.

LL-VI SLAM: enhanced visual-inertial SLAM for low-light environments

Abstract In low-light environments, the scarcity of visual information makes feature extraction and matching challenging for traditional visual simultaneous localization and mapping (SLAM) systems. Changes in ambient lighting can also reduce the accuracy and recall of loop closure detection. Most existing image enhancement methods tend to introduce noise, artifacts, and color distortions when enhancing images. To address these issues, we propose an innovative low-light visual-inertial (LL-VI) SLAM system, named LL-VI SLAM, which integrates an image enhancement network into the front end of the SLAM system. This system consists of a learning-based low-light enhancement network and an improved visual-inertial odometry. Our low-light enhancement network, composed of a Retinex-based enhancer and a U-Net-based denoiser, enhances image brightness while mitigating the adverse effects of noise and artifacts. Additionally, we incorporate a robust Inertial Measurement Unit initialization process at the front end of the system to accurately estimate gyroscope biases and improve rotational estimation accuracy. Experimental results demonstrate that LL-VI SLAM outperforms existing methods on three datasets, namely LOLv1, ETH3D, and TUM VI, as well as in real-world scenarios. Our approach achieves a peak signal-to-noise ratio of 22.08 dB. Moreover, on the TUM VI dataset, our system reduces localization error by 22.05% compared to ORB-SLAM3, proving the accuracy and robustness of the proposed method in low-light environments.

Simple power-efficient preamplifier-shaper channel for readout interface of silicon detectors

Simple power-efficient preamplifier-shaper channel for readout interface of silicon detectors

Design of geostationary orbit ultrawide FOV long-wave infrared imaging spectrometer.

The geostationary orbit imaging spectrometer offers distinct advantages for diverse applications in remote sensing. To enhance swath and data richness, there is a growing trend toward spectrometers with broader fields of view (FOV) and extended slit lengths. Optical systems equipped with these features face significant challenges in aberration correction. This paper investigates the parameters of geostationary orbits and designs a spectroscopic system capable of achieving ultrawide FOV without the need for stitching spectrograph subsystems. Additionally, it also designs a front-end telescope system that matches the spectroscopic system. The spectroscopic system features a slit length of 240 mm, employing an enhanced Offner structure for a long slit spectroscopic system, incorporating a freeform surface on the third mirror. To inhibit the effects of radiation stray light, the system's exit pupil is controlled to be positioned in front of the image plane to facilitate matching with the cold shield. The analysis indicates that the spectral resolution of the long-wave infrared imaging spectrometer system is 50 nm, with a total of 90 spectral sampling channels. The system's spatial resolution is 100 m, enabling a swath width of 400 km. Furthermore, the modulation transfer function (MTF) exceeds 0.42 at the Nyquist frequency of 8.35 lp/mm. The maximum RMS radius of the system is less than 27 μm at wavelengths ranging from 8 to 12.5 μm.

An App-Assisted Frontend of Robot Gait Training System for Lower Limb Rehabilitation

An App-Assisted Frontend of Robot Gait Training System for Lower Limb Rehabilitation

Implementing an Agile-Driven Centralized System: A Key Strategy for Optimizing Stock Administration Efficiency

The stock administration program architecture involves user roles, such as managers, administrators, and staff, interacting with the system's components to access and process data. The system's development relies on hardware and application elements, including databases, front-end and back-end systems, code editing tools, and local servers. A use-case approach organizes stock administration, with diagrams showing users' interactions with the system. Administrators can manage stock by adding, modifying, or deleting items, while the system provides reports for analysis and decision-making. Staff members can view inventory, adjust stock levels, and receive alerts for low stock. Managers oversee stock requests, analyze reports, and manage staff accounts. A SUS questionnaire was administered to assess usability, revealing user perceptions based on ease of use, efficiency, and satisfaction. Comparing SUS scores across user roles helps identify usability challenges. High scores indicate that the system is user-friendly and effective, while lower scores suggest areas for improvement through training, redesign, or feature enhancements. Users reported high usability for ease of use, with support requirements scoring second highest. Staff ratings highlighted areas for improvement, such as stock level notifications, which can be addressed through redesign or training to enhance system usability.

Design of a liposome casein hydrogel as an efficient front-end homeostatic anthocyanin loading system

Proteins have been studied and applied to improve the stability of anthocyanins (ACNs), but the changes in the pH microenvironment during the preparation of steady-state systems are often ignored, and more attention is given to the stability of the system after preparation. In this study, we propose the "anthocyanin front-end homeostasis strategy", which involves designing a system can protect anthocyanins under acidic conditions so that more anthocyanin prototypes can be loaded inside the protein. Anthocyanins are encapsulated in liposomes (Lip) at pH3.0 and combined with casein methacrylate (CSMA) to form Anthocyanin-loaded liposomes/CSMA hydrogel (Lip@ACNs/CSMA), with good physical properties and good blood compatibility. The system increased the hydrogen peroxide scavenging capacity by 1.16mg Vc equiv./mg ACNs and the cellular antioxidant activity by 17.55μM quercetin/100mg ACNs, the photo and thermal storage stability increased by 36.50% and 30.71%, the digestive rate increased by 17.50%, and the biological availability increased by 0.0049mg/mL. This study designed a liposome casein hydrogel as an efficient front-end homeostatic anthocyanin loading system and provided a new approach for improving the stability of anthocyanins.

Design and simulation of a bioimpedance detection analog front-end targeting medical applications

This paper presents the design of a bio-impedance detection analog front-end system, which is critical for continuous monitoring of physiological signals in the prevention and treatment of diseases such as coronary heart disease in the context of an aging population. The analog front-end system employs a capacitive-coupled chopper instrumentation amplifier with a fully differentially folded cascode operational amplifier as the core amplifier, and a common-mode feedback loop is introduced to improve the common-mode rejection ratio due to the high requirement for noise suppression. The power supply voltage of the design is 3.3V, achieving a total current consumption of 45uA and a total power consumption of 0.15mW. The core operational amplifier provides a maximum open-loop gain of 58 dB and a -3dB bandwidth of 8.2KHz. The power supply rejection ratio for the positive supply and ground achieved values of 102dB and 108dB, respectively. The common-mode rejection ratio of the chopper instrumentation amplifier can reach 109 dB, which is critical for suppressing common-mode noise.

Design of electronic system for 2D hard X-ray spectrum camera on EAST

Design of electronic system for 2D hard X-ray spectrum camera on EAST

Front-End Development on A Web-Based Teaching Material Repository System at SMK Diponegoro 1 Jakarta

In the current digital era, information technology has greatly dominated the field of education, and the use of websites stands as a primary example. Websites play a crucial role in storing and conveying information. One such example is the school repository website. Having a storage medium for instructional materials can provide advantages to users, especially schools. Currently, at SMK Diponegoro 1 Jakarta, there is no dedicated storage for instructional materials. A single information system, Google Drive, is used to store all documents and information. The purpose of this research is to present and enhance the front-end appearance and functionality of the web-based Instructional Material Repository System. The development method employed is the Waterfall model, utilizing the Bootstrap framework and Javascript to construct a high-fidelity prototype of the system's front-end. Throughout the development process, black box testing was conducted to ensure the success of the system's functionality and usability. The testing results demonstrated that all tasks were successfully executed with a 100% success rate.

LIBRARY LINX: BRIDGING EDUCATION WITH EFFICIENT LIBRARY MANAGEMENT

Abstract: The School Library Management System (SLMS) frontend is an essential component designed to provide a user-friendly interface for students, teachers, and librarians to efficiently manage library resources. The frontend interface serves as the gateway for users to access various features and functionalities offered by the SLMS. The popular JavaScript package React.js was utilised to build the front end of the SLMS. A dynamic and responsive interface provided by React.js makes it simple for users to navigate the library system. React.js simplifies component-based development by allowing for code reuse and modularity. Node.js is used to perform server-side logic and data administration on. Index Terms –Front-end Development , React Js , Design , React Dev Tools.

Assessment of 180 nm double SOI technology for analog front-end design with back-gate voltage

This paper provides an assessment of the electrical and noise performance in the 180 nm double silicon-on-insulator (DSOI) technology, which shows advantages for analog front-end radiation detectors. For the first time, the impact of the back-gate voltage on the electrical and noise performance of DSOI MOSFETs is investigated. The transconductance-to-current (gm /ID ) ratio and low-frequency (1/f) noise were measured as a function of the MOS device types (NMOS/PMOS), gate length, and bias condition of front- and back-gates. Experimental results show that positive back-gate voltage deteriorates the gm /ID ratio of the MOSFETs in weak inversion region. The DSOI NMOS devices overwhelm the PMOS with better gm /ID and 1/f performance. The DSOI devices have a comparable 1/f noise with the 180 nm SOI counterparts. With negative back-gate voltage applied, the low frequency noise performance of NMOS is improved. This assessment of DSOI technology gives a guideline for the readout circuit design in detector front-end systems.

Front-end speech processing system with SVM algorithm in rail passenger flow management

In order to achieve the goal of dynamically adjusting daily passenger flow to effectively control the overall efficiency of the transportation system, this study constructs a real-time monitoring and prediction system for subway passenger flow based on front-end voice processing technology and support vector machine models. The study first conducted a railway passenger flow analysis, and then used a support vector machine model to construct a preliminary prediction system. In order to achieve global optimization, the study also introduced particle swarm optimization algorithm to construct an optimization prediction model based on PSO-SVM. The results show that the proposed PSO-SVM method has undergone 48 iterations of training, and the predicted values closely match the actual passenger flow curve. The maximum RE error is 2%, and the overall prediction error is 98%. The decision coefficient of PSO-SVM is 0.998932. Therefore, this indicates that it has high performance and feasibility in predicting and controlling passenger flow during peak hours of urban rail transit.

A proposal for a fast infrared bursts detector

The gravitational wave GW170817 from a binary neutron star merger and the simultaneous electromagnetic detection of the GRB170717A by Fermi Gamma-Ray Space Telescope, opened a new era in the multi-messenger astronomy. Furthermore, the GRBs (Gamma-Ray Bursts) and the mysterious FRBs (Fast Radio Bursts) have sparked interest in the development of new detectors and telescopes dedicated to the time-domain astronomy across the electromagnetic spectrum. Time-domain astronomy aims to acquire fast astronomical bursts in temporal range between a few seconds down to 1 ns. Fast InfraRed Bursts (FIRB's) have been relatively understudied, often due to the lack of appropriate tools for observation and analysis. In this scientific scenario, the present contribution proposes a new detection system for ground-based reflecting telescopes working in the mid-infrared (mid-IR) range to search for astronomical FIRB's. Experience developed in the diagnostics for lepton circular accelerators can be used to design temporal devices for astronomy. Longitudinal diagnostic instruments acquire bunch-by-bunch particle shifts in the direction of flight, that is equivalent to temporal. Transverse device integrates the beam signal in the horizontal and vertical coordinates, as standard telescopes. The proposed instrument aims to work in temporal mode. Feasibility study tests have been carried out at SINBAD, the infrared beam line of DAFNE, the e+e- collider of INFN. SINBAD releases pulsed infrared synchrotron light with 2.7 ns separation. The front-end detector system has been evaluated to detect temporal fast infrared signals with 2–12 μm wavelengths and 1 ns rise times. The present contribute aims to be a step toward a feasibility study report.