Ismail Baxhaku

Mr. Ismail Baxhaku

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2023 in Applied Sciences
Verified
Journal Article
Open access
PDF file
VMVanja Mandric
Vanja Mandric
SRSlavko Rupcic
Slavko Rupcic
SRSnježana Rimac-Drlje
Snježana Rimac-Drlje
IBIsmail Baxhaku
Ismail Baxhaku
In this article, an aperture antenna excited by a waveguide with a circular cross-section and covered with a dielectric plate was analyzed via simulation calculation and verified via measurements. The influence of the geometrical and electromagnetic parameters of the dielectric plate on the reflection coefficient S11 of the antenna opening was systematically analyzed. The geometrical parameters taken in this analysis are the thickness d and the width/length h1/h2 of the dielectric plate. The electromagnetic parameters used in this analysis are the real and the imaginary part of permittivity (εr, tan δ) and the electrical conductivity of the dielectric plate (σ). The simulation calculation and analysis included other structural and electromagnetic parameters of the dielectric plate (density of the radome material, relative permeability, and magnetic loss tangent (ρ, µr, and tan δµ, respectively)), but the results show that in the range of real values of these parameters for the materials used for the dielectric plate, they had no significant influence on the reflection coefficient. The results show that impedance-matched antennas with very low values of the reflection coefficients S11 at the resonant frequency can be realized by changing the geometrical and electromagnetic parameters of the dielectric plate material. The results are presented for a circular aperture antenna on a planar grounded plane with a dielectric plate on the opening, and the achieved lowest values of the S11 parameter were −45.17 dB (simulated) and −43.93 dB (measured) at the frequencies of 1.7820 GHz and 1.7550 GHz, respectively. The estimated values of the dielectric plate parameters in this case are thickness d = 11.08 mm (0.67 λ); width × length of grounded plane and dielectric plate h1 × h2 = 423 × 450 mm2 (2.51 × 2.67 λ); relative permittivity 2.5, tan δ = 0.09, μr = 1, tan δμ = 0.00, ρ = 1200 kg·m−3; and electrical conductivity σ = 0 S/m. The simulation calculation results were verified by measuring the reflection coefficient S11 on the created laboratory model of the aperture antenna with the dielectric plate and showed a very good match.

8 December 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
SRSlavko Rupcic
Slavko Rupcic
VMVanja Mandric
Vanja Mandric
IBIsmail Baxhaku
Ismail Baxhaku
This study presents an in-depth investigation of an eccentric double-ring microwave resonator comprising two asymmetrically coupled conductive loops connected at a single point. The configuration was systematically analyzed using analytical modeling, full-wave electromagnetic simulations (Ansys HFSS), and experimental characterization. Analytical formulations based on the resonant condition of thin conductive rings provided theoretical estimates of the fundamental and higher-order eigenmodes, while simulations yielded accurate resonance frequencies, transmission responses, and electric field distributions. The transmission coefficient (S21) exhibited two distinct resonance dips at 436 MHz and 708 MHz, confirming strong inter-ring coupling and hybrid mode formation. Electric field mapping revealed pronounced confinement within the resonator region (E > 170 V/m) and substantial attenuation of the transmitted field (E < 13 V/m), demonstrating efficient electromagnetic energy suppression. Experimental results showed excellent consistency with theoretical predictions. This paper aims to establish a compact, low-cost, and tunable resonant structure capable of frequency-selective attenuation and field confinement without using lossy materials. Unlike conventional symmetric resonators, the eccentric configuration enables enhanced coupling control and modal diversity, making it highly relevant for the design of next-generation electromagnetic shielding, filtering, and sensing systems.

19 October 2025 in Applied Sciences
Verified
Journal Article
Open access
PDF file
VMVanja Mandric
Vanja Mandric
SRSlavko Rupcic
Slavko Rupcic
BPBogdan Pavkovic
Bogdan Pavkovic
IBIsmail Baxhaku
Ismail Baxhaku
The proliferation of wireless networking solutions, which are omnipresent in our daily lives, has led to increased exposure to the energy of electromagnetic (EM) waves in the higher frequency range, raising concerns about their impact on human health. Investigating the propagation of EM waves through multilayer structures can shed light on the future direction of effective protection and shielding solutions. The paper provides a comparative study that examines EM wave propagation through a multilayered composite structure. The structure combines Plexiglas plates (acrylic, polymethyl methacrylate), a dielectric material, with one or more layers of conductive YSHIELD HSF54 paint to reduce EM field intensity. The paint’s carbon-based particle composition promises effective field attenuation. Our side-by-side comparative real-world measurements and simulation results showcase correlation. We further demonstrated the benefits of applying a layer of conductive YSHIELD HSF54 paint over Plexiglass to form a composite structure, with the initial layer contributing to attenuation of approximately 20 dB. Finally, the results were validated by calculating Morozov’s first- and second-order analytical approximations for the transmission parameter S21—the calculated values accurately trace both the simulations and measurements. The research concludes that shielding, which is used as a method of protection against EM radiation in many industrial devices, can also be used in procedures to protect human habitats by selecting new, innovative, and affordable materials and structures.

28 January 2026 in Engineering Proceedings
Verified
Conference Paper
Open access
PDF file
VMVanja Mandric
Vanja Mandric
SRSlavko Rupcic
Slavko Rupcic
BPBogdan Pavkovic
Bogdan Pavkovic
IBIsmail Baxhaku
Ismail Baxhaku
This article investigates the behavior of an electromagnetic field passing through a composite material—a multilayered structure. The material consists of a dielectric material polymethyl methacrylate (acrylic, plexiglass) to which one or more layers of conductive paint are applied to attenuate the field strength. This field attenuation is possible precisely because of the chemical structure of the paint, which contains carbon-based particles and is therefore very successful in its purpose. Research was carried out with the stated aim—simulations and confirmation by measurements—to investigate the attenuation of the EM field when passing through a multi-layered structure.