NOPR Community:http://nopr.niscpr.res.in/handle/123456789/632026-08-19T05:54:19Z2026-08-19T05:54:19ZA Novel Compact Design of Multi-Band Frequency Selective Surface for 5G Applications using a CNN-GNN Hybrid Network OptimizationJagadesh, TPalanisamy, SatheeshKumarSathishkumar, NSingaram, MR P Rajarathnam, Dhttp://nopr.niscpr.res.in/handle/123456789/683102026-08-19T04:56:52Z2026-08-01T00:00:00ZTitle: A Novel Compact Design of Multi-Band Frequency Selective Surface for 5G Applications using a CNN-GNN Hybrid Network Optimization
Authors: Jagadesh, T; Palanisamy, SatheeshKumar; Sathishkumar, N; Singaram, M; R P Rajarathnam, D
Abstract: In this paper, a new compact design of multi-band Frequency Selective Surface (FSS) optimized using a hybrid
Convolutional Neural Network-Graph Neural Network (CNN-GNN) framework for advanced 5G communication systems is
proposed. The suggested FSS operates in five different frequency bands, i.e., 4.0788 GHz, 17.080 GHz, 21.559 GHz, 27.928
GHz and 29.870 GHz with bandwidths of 2.686 GHz and 1.849 GHz in important bands. Unlike the usual designs with only
one or two bands with limited bandwidths, the proposed FSS provides significant multi-band capabilities while maintaining
excellent angular stability up to 80° for both Transverse Electric (TE) and Transverse Magnetic (TM) polarizations. In
addition, the design with the compact unit cell size of 0.0814λ0×0.0814λ0 is suitable for integration into the contemporary
5G devices, including the wearable and automotive systems. The FSS displays effective cross-polarization suppression,
directional radiation patterns, and minimal backward interference, with enhanced antenna gain and dependable signal
filtering at varied incident angles, through rigorous simulation and experimental validation. The implementation of a CNNGNN
hybrid optimization framework to improve the FSS shape is one of the main contributions of this work, combining the
characteristics of localized feature extraction and global dependency modeling. The hybrid technique results in a decrease of
return loss and better selectivity in frequency than traditional designs and better performance metrics. Experimental results
are in good agreement with simulations, confirming the robustness of the design and its practical applicability. The
suggested FSS surpasses the existing solutions with respect to multi-band operation, polarization stability and bandwidth. It
is a better choice for several 5G applications such as MIMO systems and mmWave technologies. The study solves important
gaps in the state-of-the-art via a compromise between compactness, efficiency and advanced optimization, opening the way
for scalable and high-performance 5G infrastructures.
Page(s): 829-8412026-08-01T00:00:00ZEnhanced Energy Harvesting Performance of Flexible PVDF Piezoelectric Nanogenerators using SnS₂/SnSe₂ Heterostructure as NanofillersDobhal, PragyaKumar, UmeshDahiya, AnkitaSingh, Bhartihttp://nopr.niscpr.res.in/handle/123456789/683092026-08-19T04:53:08Z2026-08-01T00:00:00ZTitle: Enhanced Energy Harvesting Performance of Flexible PVDF Piezoelectric Nanogenerators using SnS₂/SnSe₂ Heterostructure as Nanofillers
Authors: Dobhal, Pragya; Kumar, Umesh; Dahiya, Ankita; Singh, Bharti
Abstract: The effect of 2D transition metal dichalcogenides (TMDCs) including SnS2, SnSe2, their heterostructure (SnS2/SnSe2)
and Polyvinylidene fluoride (PVDF) based composite films for improved performance of piezoelectric nanogenerators
(PENG) is reported. SnS2, SnSe2 and SnS2/SnSe2 heterostructure were synthesized using hydrothermal method. These
TMDC materials were incorporated within a PVDF matrix to create flexible thin films using the solution-casting method in
order to investigate their outcome as nanofillers within the PVDF polymer framework. X-ray diffraction (XRD) confirmed
the phase purity of SnS2, SnSe2 and their heterostructure, while the Raman spectra verified vibrational modes indicating high
crystallinity and interfacial coupling. The enhancement of piezoelectric behaviour was revealed by Fourier transform
infrared spectroscopy (FTIR), which showed an increment in the β-phase of PVDF post adding the TMDC nanofillers.
PVDF/SnS2/SnSe2 heterostructure based nanogenerator exhibited the maximum open circuit voltage (peak-to-peak) (Voc) of
13.2 V and short circuit current (Isc) of 0.87 μA. This improvement is linked to the synergistic effect of the formation of a
heterointerface, facilitating charge separation, enhanced stress transfer and polarization due to asymmetric charge
distribution at the interface. The generated voltage from the PENG device was used to power an LED. Therefore, our work
highlights the application of 2D heterostructure engineering for improving piezoelectric performance and next-generation
flexible energy harvesting devices.
Page(s): 842-8522026-08-01T00:00:00ZAnalysis and Design of MCB Compliant On-Board Charger based on Topologies, Efficiency, Losses, and AutomationKumar Singh, ArvindOhri, JyotiM P R, Prasadhttp://nopr.niscpr.res.in/handle/123456789/683082026-08-19T04:49:06Z2026-08-01T00:00:00ZTitle: Analysis and Design of MCB Compliant On-Board Charger based on Topologies, Efficiency, Losses, and Automation
Authors: Kumar Singh, Arvind; Ohri, Jyoti; M P R, Prasad
Abstract: This paper presents a structured design approach for an Onboard Charger (OBC) used in electric vehicles (EVs) and Marine
metro vehicles, encompassing both hardware and software perspectives. The OBC architecture is typically divided into two stages
the Power Factor Correction (PFC) stage and the DC-DC converter stage. For high-voltage battery charging that follows a Constant
Current and Constant Voltage profile, a Boost PFC combined with a DC-DC converter controlled by an algorithm is considered an
effective solution. Three PFC topologies are explored: Conventional Boost PFC, Interleaved Boost PFC, and Semi-bridgeless PFC.
For the DC-DC conversion stage, the paper discusses Full-Bridge Converter, Series Resonant Converter (SRC), and Phase-Shift
Full-Bridge Converter. To automate the switching operation of the Boost Converter, a Proportional-Integral (PI) controller is
implemented. Beyond hardware design, the paper introduces a method to fully automate OBC operations by integrating the
Renesas RH850 E2M microcontroller. This next-generation automotive power train MCU enhances the OBC with intelligent
charging capabilities. Specific ECU software modules of the RH850 E2M are mapped to corresponding ECU hardware
components within the OBC and the EV system. These modules enable smart features such as adaptive charging control, fault
detection, and system optimization. A logical model of key ECU software modules responsible for smart charging is developed and
simulated using MATLAB Simulink and Simscape. The simulation results validate the proposed design and demonstrate its
potential for efficient and intelligent EV charging.
Page(s): 853-8692026-08-01T00:00:00ZCFDITA-Based Mixed-Mode Biquad Filter with Grounded Capacitors and Independent Q ControlAnupamKumar, AtulVir Singh, Sajaihttp://nopr.niscpr.res.in/handle/123456789/683072026-08-19T04:40:09Z2026-08-01T00:00:00ZTitle: CFDITA-Based Mixed-Mode Biquad Filter with Grounded Capacitors and Independent Q Control
Authors: Anupam; Kumar, Atul; Vir Singh, Sajai
Abstract: This work introduces a compact multi-mode biquad filter utilizing a Current Follower Differential Input
Transconductance Amplifier (CFDITA). The suggested circuit design is resistor less and incorporates two CFDITAs along
with two grounded capacitors exclusively. It functions in all four possible modes: voltage-mode (VM), current-mode (CM),
transadmittance-mode (TAM), and transimpedance-mode (TIM). In CM, the proposed circuit achieves all filtering
functions, including low-pass, high-pass, band-pass, band-reject and all-pass responses. Consequently, the suggested circuit
serves as a universal filter in CM. The main characteristic of the proposed multi-mode filter includes the use of minimal,
grounded passive components, which removes the requirement for input matching conditions. It sustains low input
impedances for current inputs and high input impedances for voltage inputs, making it ideal for cascading. It operates
effectively at higher frequencies (10.3 MHz), uses low supply voltages (±1.25 V), and consumes low power (1.32 mW).
Additionally, it allows for independent and electronic control of the pole frequency and quality factor through the bias
currents of the CFDITA. PSPICE simulation results utilizing 0.18 μm CMOS technology confirm the theoretical findings.
Furthermore, the proposed circuit is experimentally verified for a voltage-mode low-pass filter response.
Page(s): 870-8792026-08-01T00:00:00Z