High Gain Research Articles

A wideband high-PSR OCL LDO using a gain-relaxed OTA featuring dynamic complex zeros frequency compensation

This article proposes an Output-Capacitor-Less (OCL) Low-Dropout (LDO) regulator with an assisted positive feedback loop technique, which mimics a negative resistance, along with a single common-gate stage. Conventional techniques utilize multistage high-gain OTA to achieve a high DC loop gain. However, such an OTA suffers from high power consumption and sophisticated frequency compensation mechanisms. Instead, the use of a single-stage relatively low-gain OTA helps to extend the bandwidth. Then, the overall DC loop gain is maximized by the proposal of a novel negative resistance circuit. To further improve the PSR, a bulk-driven ripple canceling path that is insensitive to process corners is proposed making the LDO suitable for high-PSR applications. Stability is another challenge in the design of OCL LDOs due to its associated complex poles. We propose a new frequency compensation technique by introducing two complex zeros to eliminate these complex poles. Hence, the overall stability is improved. Since these complex poles location vary from light to heavy loads, the proposed zeros dynamically change accordingly. Besides, this suggested mechanism has been analyzed using the generalized time-and-transfer constants (TTCs) circuit analysis technique. Under heavy load conditions, the suggested LDO has attained phase and gain margins of 62.8° and 29 dB, respectively. Moreover, Monte Carlo simulations along with process and temperature variations have been investigated to prove the reliability of such a frequency compensation technique. The proposed LDO has been implemented in 65 nm CMOS technology node with a short pass transistor length of 100nm. The simulation results reveals that the LDO draws 299.4μA of quiescent current under light load conditions and 296.8μA under heavy load conditions (including the bandgap voltage reference). The suggested LDO functions at 1.2V supply voltage, delivers 0.93V output voltage and can handle a load current up to 10mA with load regulation of 17μV/mA, line regulation of 2.22mV/V, and PSR of −48.7dB at low frequencies. The PSR at 1MHz is at least −32.5dB which is superior to the reported recent LDOs.

A high gain microwave and millimeter-wave-based balanced antipodal Vivaldi antenna with a parasitic patch and a half-spherical shaped dielectric lens

This paper presented the design and performance analysis of a high-gain balanced antipodal Vivaldi antenna (BAVA) integrated with a parasitic patch and a half-spherical shaped dielectric lens, specifically designed for microwave and millimeter-wave applications. Constructed with a Teflon substrate (εr = 2.1, tanδ = 0.0002) and energized by a 50-ohm microstrip feedline, the innovative design incorporated a parasitic patch and three different types of dielectric lenses: half-circular, conical, and half-spherical shaped. The half-spherical dielectric lens significantly enhanced performance, achieving a gain of 20.54 dB, side lobe level (SLL) of -18.15 dB, and a maximum beam squint of 1.59 degrees. Additionally, it exhibited a 98% radiation efficiency, a front-to-back ratio of 31.75 dB, and a half-power beamwidth (HPBW) of 6.7 degrees. The incorporation of a parasitic patch and a half-spherical shaped dielectric lens enhanced the antenna's performance. Comparative analysis with existing antennas underscored the superiority of the proposed design, positioning it as a promising solution for microwave and millimeter-wave communication systems, radar, and sensing applications.

Quasi Z source direct matrix converter based K- to three-phase wind energy conversion system using maximum constant boost current control modulation technique

The conversion system for wind energy has no restriction on the number of output phases. K numbers of output phases can be converted into standard grid-connected three-phase supply using a quasi-Z source direct matrix converter (QZSDMC). The obtained input supply may be five phases from the wind energy conversion system with continuously variable frequency as well as variable terminal voltages. Using the proposed QZSDMC converter with maximum constant boost current control modulation technique constant three-phase voltages as well as frequency can be maintained at the grid side. Additionally, the energy conversion system has high output voltage gain. The proposed converter as well as the modulation technique produces the maximum voltage transfer ratio of 1.05. The output voltage gain reached nearly 1.99 compared with the traditional power converters. The voltage THD and current THD are maintained within the acceptable limit of 5.3 and 3.6 respectively. The power factor have been maintained nearly unity throughout the all mode of operations. To stabilize the grid frequencies and grid voltages additional control blocks are used. This research article presents simulation results for the proposed QZSDMC converter with a maximum constant boost current control modulation technique. Also, the proposed scheme has been validated with suitable experimental results.

High Voltage Gain Soft-Switching Bidirectional DC-DC Converter With High Extendibility Using Coupled Inductor

High Voltage Gain Soft-Switching Bidirectional DC-DC Converter With High Extendibility Using Coupled Inductor

High Voltage Gain Three-Level DC–DC Converter With Switched-Capacitor Technique for DC Wind Farms

High Voltage Gain Three-Level DC–DC Converter With Switched-Capacitor Technique for DC Wind Farms

Wideband and High Gain Elliptically-inspired 4 × 4 MIMO antenna for millimeter wave applications

An elliptically-inspired microstrip antenna is utilized in this paper to operate in the V-band (52.9 – 70 GHz) of the millimeter frequency range for 5G applications. 2-port and 4-port multi-input-multi-output (MIMO) configurations are designed, fabricated, and tested to validate the desired radiation and impedance characteristics. The measured results mimic the simulated ones in terms of scattering parameters, and MIMO parameters. Although the 4-port footprint is considered miniaturized (26 × 26 mm2), it provides a reduced coupling between ports (≤ 20 dB) with an improved gain ranging from 8 to 10.1 dBi. Furthermore, the achieved MIMO parameters (ECC, DG, CCL, and MEG) are distinct with values of 0.006, ≥ 9.96 dB, ≤ 0.4 bits/s/Hz, and -3 dB, respectively. The introduced 4-port MIMO antenna is compared with the state-of-the-art antennas and this assures that the suggested model has built-in size, wider impedance bandwidth, and higher isolation with an improved diversity characteristic confirming the possibility of the presented MIMO antenna to be a challenging candidate for 5G wireless communications.

Precision polishing force control technology of abrasive belt-wheel polishing servo control system based on HGO-SMC

Due to cylinder friction, valve dead zone effect, flow nonlinearity, and measurement noise exist in pneumatic system. In the actual machining, it is difficult to achieve precise control of the pneumatic servo polishing system using the traditional PID algorithm, so the machining accuracy of the blades cannot be guaranteed. A sliding mode control (SMC) method based on high gain observer (HGO) is proposed. The HGO observes the output signal of the system and feeds the estimated signal back to the SMC to ensure that the observation error is uniform ultimate boundedness. Simulation and experiments show that compared with the PID algorithm, the steady-state error of HGO-SMC can be reduced by 66.4%. Compared with SMC(sgn), the high-frequency chattering of HGO-SMC can be reduced by 72.5%. Moreover, the polishing processing experiment shows that HGO-SMC can improve the form and position accuracy by 52.6% and reduce the surface roughness by 55.6%, compared with the original PID control algorithm of the polishing machine tool.

A Comparative Study of a High Gain Observer and a Nonlinear Observer based on the Circle Criterion for Sensorless Induction Motor Control

A Comparative Study of a High Gain Observer and a Nonlinear Observer based on the Circle Criterion for Sensorless Induction Motor Control

Comprehensive analysis of bulk, single-cell RNA sequencing, and spatial transcriptomics revealed IER3 for predicting malignant progression and immunotherapy efficacy in glioma

BackgroundAs part of stress-triggered molecules, immediate early response 3 (IER3) dysregulation has been reported to sustain pro-oncogenic pathways and precede malignant transformation. However, the role of IER3 in glioma pathology is ill-defined.MethodsImmunohistochemistry (IHC) assay and publicly available glioma datasets were used to calculate the IER3 expression level in glioma. Wound healing, invasion and cell counting kit-8 (CCK8) assays were applied to measure the cell viability and capacities of migration and invasion of glioma cells in vitro. The immunofluorescence (IF) assay was used to assess the expression associations of IER3 with CCL2 and TGFBI. Cox regression analysis and Kaplan-Meier (K-M) curve were introduced to compute the prognosis-predicting value of IER3. Variations in copy number (CNVs), single nucleotide (SNVs), and methylation profiles were analyzed to illustrate the epigenetic modifications of IER3. Gliomas were divided into two subgroups using the restricted cubic spline (RCS) method.Results IER3was overexpressed and hypomethylated in gliomas and significantly associated with the dismal prognosis of glioma samples. Samples in the high IER3 subgroup were characterized by increased infiltration of tumor-associated monocytes/macrophages (TAMMs), as well as the elevated sensitivity to Dabrafenib, an inhibitor of BRAF. In addition, this subgroup demonstrated a low mutation rate of IDH, high gain rates of BRAF, ELTD1, and PDGFA. Gliomas with relatively low IER3 expression demonstrated a less invasive subtype and were featured by favorable prognosis, increased response to immunotherapy, and adjuvant chemotherapy plus radiotherapy. The IF assay revealed that IER3 was co-localized and co-expressed with TGFBI. The glioma cells with small interfering RNA (siRNA)-silenced IER3 displayed lower migration, invasion, proliferation, and cell viability than the control group.ConclusionsIn this study, we identified IER3 upregulation as an essential biomarker that could assist in adjuvant therapy and prognosis prediction for gliomas.

A compact circularly polarized dielectric resonator antenna with MIMO characterizations for UWB applications.

Ultra-wideband (UWB) technology is extensively used in indoor navigation, medical applications, and Internet of Things devices due to its low power consumption and resilience against multipath fading and losses. This paper examines a multiple-input multiple-output (MIMO), circularly polarized (CP) dielectric resonator antenna for UWB systems. Compact form factor, high gain, wideband response, improved port isolation, and high data rates are the major design goals. This arrangement consists of two identical DRAs with self-decoupled orthogonal orientations eliminating the need for extra decoupling structures while achieving an impressive maximum isolation of 43 dB. The corner-edge feeding mechanism of the extended feedline generates two orthogonal E-fields, facilitating circular polarization. Additionally, a printed hook-shaped stub integrated with the ground plane enhances CP performance across the two operating bands without altering the DR structure. Fabrication and testing exhibit an impressive 133 impedance bandwidth (2.5-14 GHz) with high port isolation. For a 3 dB axial ratio reference, the single-element design exhibits axial ratio bandwidths (ARBW) of 1.2 GHz (3.6-4.8 GHz) and 0.8 GHz (9.3-10.1 GHz). Remarkably, the MIMO configuration achieves a single ARBW of 0.5 GHz (3.9-4.4 GHz). Detailed investigations of MIMO performance parameters, including diversity gain, envelope correlation coefficient, channel capacity loss, and total active reflection coefficient, underscore the design's efficacy, making it a good choice for UWB wireless applications.

Low sintering temperature, interface characteristic and microwave/terahertz dielectric properties of ternary-phase Nd2O3-P2O5 based ceramics for patch antenna application

In this work, LiF was chosen as a sintering aid to lower the sintering temperature required for monoclinic NdPO4 (NPO) ceramic. A comprehensive investigation was conducted to analyze the impact of LiF on the sintering characteristics, microstructures, phase compositions, crystalline structures, interface characteristics, and microwave dielectric properties of NPO ceramic. Structure-property relationships were discussed based on the density, crystallite size, and lattice strain. The complex impedance spectroscopy revealed the mechanism underlying the interface characteristics of LiF on NPO ceramic. Additionally, far-infrared reflectance spectra and THz time-domain spectra revealed the intrinsic dielectric properties of NdPO4–1 wt.%LiF (NPO1). Notably, 1 wt.% LiF effectively reduced the sintering temperature from 1300 °C to 850 °C, significantly improving densification and dielectric properties. Typical properties such as Q × f = 55,840 GHz (at 9.58 GHz), εr = 10.4, and τf = −43.1 ppm °C−1 were obtained for NPO1 ceramic after sintering at 850 °C. Furthermore, its compatibility with Ag was explored as a prerequisite for LTCC applications. Finally, the NPO1 ceramic was designed as a microstrip antenna with high gain (6.83 dB) and low return loss (−18.85 dB) at a centre frequency of 2.56 GHz, demonstrating its potential for Wi-Fi and Bluetooth applications. This work provides a theoretical foundation and practical guidance for developing orthophosphate ceramics.

High gain super lift Luo converter for hybrid energy management systems

Recently, there has been a resurgence of interest in the development of alternative energy supplies due to rising fossil fuel prices and issues about the effects of greenhouse gas emissions on the environment. Today's demand is the design of a hybrid electric power generation system that uses solar and wind energy for remote places. This paper presents the design of an optimized hybrid renewable energy system consisting of a photo voltaic wind turbine (savinous type) with a battery and a super lift LUO converter. A solar PV module with an intelligent inverter facilitates the tracking of the maximum power point and the implementation of a battery charge controller for greater battery lifespan as well as reliable performance. Higher power output and clean energy are available from the hybrid power generation system, which combines innovative techniques with solar and wind power.

Cost-Effective High Gain Wideband Antenna with Dual Partially Reflective Surface for 5G-mmWave Application

This research presents the performance improvement of the of rectangular patch microstrip antenna. The purpose is to increase gain and bandwidth with design on the PRS (Partially Reflective Surface) dual layer technique. There is a developing the low-cost substrate-based antennas suitable for 5G millimeter-wave. The prototype antenna achieves a maximum gain of 11.8 dBi at a frequency of 25.5 GHz. The gain increases by 6 dB throughout its operational frequency range, with an OBW (Overlap bandwidth) of 20.9%, covering frequencies from 24.0 GHz to 29.9 GHz. The performance achieved results indicate that the prototype antenna can be effectively utilized for 5G millimeter-wave communication applications in Thailand.

Design of Power Dividers for Finite Dipole Subarrays with Complex Impedances

In this study, we propose a method for designing a feeding network for all port-matched and high gain dipole subarray antennas excited by uniform current mode (UCM) by considering the mutual coupling effect. By analyzing the array impedance matrix, we first calculated the active input impedance and the required excitation power. Following this, we transformed and combined the complex impedances using the proposed power divider, thus preserving the required excitation power. The design process and results of this study are demonstrated stepwise through circuit simulation. Subsequently, we fabricated and evaluated the proposed subarrays. The impedance matching performance of the UCM was found to be better than that of the conventional subarray, with their array gains being 11.5 dBi and 9.8 dBi, respectively.

Design and Implementation of an S-band Receiver for Small Satellite Based on the Manufactured Subsystems

In this work the design and implementaion of a receiver for small satellites in range of 1.9 GHz to 3.0 GHz frequency were presented. We concentrated on developing a new architecture for receiving satellites in challenging environments and integrated some of the author’s previously published designs. By using the protected mechanism for RF circuit of receiver, a mutil-stage in IF amplifier and automatic gain control in IF amplifer has been designed, this receiver has a higher gain (78 dB), a larger dynamic ranger (80 dB), a high stability and sensitivity (110 dBm) at 2.15 GHz frequency. The receiver module works well; and due to the flexible structure, easy assembly and low-cost characteristics, it can be applied for small satellites and ground stations.

A novel artificial neural network based selection harmonic reduction technique for single source fed high gain switched capacitor coupled multilevel inverter for renewable energy applications

Multilevel inverters (MLIs) are commonly used in renewable energy systems for their high-quality output, low total harmonic distortion (THD), and reduced component count. This study presents a high-gain, single-source MLI designed for renewable applications like solar or wind power. It features a novel topology with twice the voltage-boosting factor, utilizing a single DC source. The inverter achieves thirteen voltage levels using just 10 power switches and three switched capacitors. The voltage gain is achieved without the need for bulky DC-DC converters or transformers. This is accomplished by configuring the switched capacitors in series and parallel arrangements to attain the desired voltage boost. Additionally, the self-balancing capacitors eliminate the need for extra sensors. Both symmetric and asymmetric variants of the extensible configuration are investigated. The suggested design lowers the total standing voltage (TSV) while achieving high gain. A selective harmonic removal technique using artificial neural networks (ANN) reduces THD by up to 6.07 %. An extensive review of recent literature reveals significant advancements and applications of ANNs in this field. The proposed system's benefits, such as gain factor, total standing voltage (TSV), and minimized device count, are assessed. Comparative analysis reveals that the proposed topology employs fewer components and features a more simplified design. Additionally, the inverter achieves an efficiency of 96.9 %. The design is validated through an experimental prototype after being confirmed with MATLAB/SIMULINK.© YEAR The Authors. Published by Elsevier Ltd.Peer-review under responsibility of the scientific committee of the Name of the Conference, Conference Organizer Name, Year or Edition of Conference.

Feasibility study of YSO/SiPM based detectors for virtual monochromatic image synthesis.

The development of photon-counting CT systems has focused on semiconductor detectors like cadmium zinc telluride (CZT) and cadmium telluride (CdTe). However, these detectors face high costs and charge-sharing issues, distorting the energy spectrum. Indirect detection using Yttrium Orthosilicate (YSO) scintillators with silicon photomultiplier (SiPM) offers a cost-effective alternative with high detection efficiency, low dark count rate, and high sensor gain. This work aims to demonstrate the feasibility of the YSO/SiPM detector (DexScanner L103) based on the Multi-Voltage Threshold (MVT) sampling method as a photon-counting CT detector by evaluating the synthesis error of virtual monochromatic images. In this study, we developed a proof-of-concept benchtop photon-counting CT system, and employed a direct method for empirical virtual monochromatic image synthesis (EVMIS) by polynomial fitting under the principle of least square deviation without X-ray spectral information. The accuracy of the empirical energy calibration techniques was evaluated by comparing the reconstructed and actual attenuation coefficients of calibration and test materials using mean relative error (MRE) and mean square error (MSE). In dual-material imaging experiments, the overall average synthesis error for three monoenergetic images of distinct materials is 2.53% ±2.43%. Similarly, in K-edge imaging experiments encompassing four materials, the overall average synthesis error for three monoenergetic images is 4.04% ±2.63%. In rat biological soft-tissue imaging experiments, we further predicted the densities of various rat tissues as follows: bone density is 1.41±0.07 g/cm3, adipose tissue density is 0.91±0.06 g/cm3, heart tissue density is 1.09±0.04 g/cm3, and lung tissue density is 0.32±0.07 g/cm3. Those results showed that the reconstructed virtual monochromatic images had good conformance for each material. This study indicates the SiPM-based photon-counting detector could be used for monochromatic image synthesis and is a promising method for developing spectral computed tomography systems.

An ultra-high gain boost converter with low switching stress for integrated multi-energy storage systems

In this paper, a high-gain low-switching-stress coupled-inductor with high voltage step-up voltage multiplier cells quadratic boost converter (VMC-QBC) is proposed. The turn ratio of the coupled inductors and the switch duty cycle increase the dynamic gain, and the two degrees of freedom adjustment and modularity of the voltage multiplier cells (VMC) make the structure more flexible. The use of the same drive signal for both switches makes control easier. While achieving multi-stage boosting and multiplication boosting from low to medium duty cycle, the passive clamping circuit absorbs the energy leaked by the coupled inductor, thus reducing the stress on the switching tube and alleviating the diode reverse recovery problem. A non-ideal model with parasitic parameters is developed to analyse the real voltage gain and the converter losses to give design guidelines. A 300 W prototype is designed and tested. The state space model of the converter is established and the working principle is analysed. Compared to other high-gain quadratic boost converters, the proposed converter has continuous input current, common ground characteristics, and high voltage gain at low to medium duty cycles to accommodate integrated multi-energy storage systems.

Analysis and Design of Efficient High Voltage Gain Interleaved Boost Converter for Solar PV System

Analysis and Design of Efficient High Voltage Gain Interleaved Boost Converter for Solar PV System

Achieving a Noise Limit with a Few-layer WSe2 Avalanche Photodetector at Room Temperature.

We engineered a two-dimensional Pt/WSe2/Ni avalanche photodetector (APD) optimized for ultraweak signal detection at room temperature. By fine-tuning the work functions, we achieved an ultralow dark current of 10-14 A under small bias, with a noise equivalent power (NEP) of 8.09 fW/Hz1/2. This performance is driven by effective dark barrier blocking and a record-long electron mean free path (123 nm) in intrinsic WSe2, minimizing dark carrier replenishment and suppressing noise under an ultralow electric field. Our APD exhibits a high gain of 5 × 105 at a modulation frequency of 20 kHz, effectively balancing gain and bandwidth, a common challenge in traditional photovoltaic-based APDs. By addressing the typical challenges of high noise and low gain and minimizing dependence on high electric fields, this work highlights the potential of 2D materials in developing efficient, low-power, and ultrasensitive photodetections.