A5045070107- Antenna Design and Analysis
- Antenna Design and Optimization
- Advanced Antenna and Metasurface Technologies
- Microwave Engineering and Waveguides
- Electromagnetic Scattering and Analysis
- Energy Harvesting in Wireless Networks
- Advanced MIMO Systems Optimization
- Advanced Wireless Communication Techniques
- Satellite Communication Systems
- RFID technology advancements
- Microwave and Dielectric Measurement Techniques
- Electromagnetic Simulation and Numerical Methods
- Electromagnetic Compatibility and Measurements
- Wireless Body Area Networks
- Millimeter-Wave Propagation and Modeling
- Direction-of-Arrival Estimation Techniques
- Structural Analysis and Optimization
- Particle accelerators and beam dynamics
- Wireless Communication Networks Research
- Photonic and Optical Devices
- Electromagnetic Fields and Biological Effects
- Radio Astronomy Observations and Technology
- Wireless Sensor Networks for Data Analysis
- Telecommunications and Broadcasting Technologies
- Water Quality Monitoring Technologies
Democritus University of Thrace
2022-2025
Aristotle University of Thessaloniki
2011-2021
Alexander Technological Educational Institute of Thessaloniki
2007
This work presents a comparative analysis of microwave ablation applicators, including both antenna-based and open waveguide designs, which are guided inserted into tumors via catheters. Applicators previously proposed in the literature evaluated through electromagnetic thermal simulations. The objective is to assess temperature distribution within tumor surrounding healthy tissues; with focus on identifying patterns heat diffusion. Although variety applicators have been designed, each...
The general objective of the work is to propose, examine, and study innovations needed, providing a roadmap in order place next generation wireless communication vision concepts into technological reach. main trends directions are identified; relative challenges addressed; needed solutions anticipated, proposed, evaluated. In detail, address role antenna system evolution, at hand, we examine addressed by increase degrees freedom radiator systems. Specifically, provided gMIMO, reconfigurable...
Novel dual-element antenna arrays suitable for small devices of multiple-input-multiple-output (MIMO) applications have been designed and fabricated. The elements semi-printed structure, are fractally shaped, operate in ISM (2.4-2.489 GHz) band as well between 5 6 GHz. Although the size prototypes is positioned too close to each other, correlation coefficients lower than 0.1 satisfactory levels mean effective gain obtained.
A Darknet is an overlay network within the Internet, and packets' traffic originating from it usually termed as suspicious. In this paper common machine learning classification algorithms are employed to identify traffic. ROC analysis along with a feature importance for best classifier was performed, provide better visualisation of results. The experiments were conducted in new dataset CIC-Darknet2020 classifiers trained both binary multiclass classification. first task, there two classes:...
A novel miniature all-polarization Γ antenna array for demanding 5G and Internet of Things (IoT) applications is proposed. The designed to be able perform Direction Arrival (DoA) Beamforming keeping antenna's footprint as minimal possible fit in or wrapped around any IoT device. It a non-uniform square comprised right corner dipoles which are mirror placed additionally allow all polarization property. These properties inherited from its approximate equivalence cross-dipole with additional...
Butler matrix networks are well established as beam forming for phased antenna arrays. The challenge we address in this work is to cover the entire, (advanced 5G or 6G), FR3 band (7-24 GHz) with a single network, while retaining low losses and minimal size. employed multilayer topology also established, however, matching between utilized hybrid couplers phase shifters constitutes major such wideband operation. This achieved herein employing meander lines appropriate curvature introducing two...
This work aims at the establishment of a methodology providing characteristic modes mobile devices realistic models including their metallic parts as well material-dielectric loading. A modified integral equation Moment method is employed to yield impedance matrix such metal-dielectric structures. In turn mode approach formulate and solve related eigenproblem.
Low sidelobe level control of the two-way pattern shared circular planar radar arrays is presented. The are coming from sampling properly designed apertures. resulted have element excitations with amplitude taper or equivalent space thinned certain spatial density. apertures either uniform two-weight distribution. Two conditions that give ratio size between receive and transmit their weight excitation imposed. In first condition, appearance a aperture at null one used. second two higher...
An optimization procedure for the layout assessment of electrically large but finite planar arrays is presented. The synthesis takes into account desired directivity pattern that prescribed employing bound constraints. Moreover, size radiators taken account, which results in a hard nonoverlapping, between elements, constraint. latter should not be violated if we want attained solution only to obey far-field mask, also physically realizable. As stated, problem twofold. antenna design...
A Butler matrix (BM) for UMTS applications is presented. The was fabricated by conventional photolithography on a single laminate. design compact and complies with the required bandwidth. based use of an elliptical coupler certain geometrical characteristics, Lange as crossover. Furthermore, design-scaling procedure that produces N times using two (N/2)times(N/2) matrices given. presented performance extrapolations clarify potential scalability our approach
In this work, the design, fabrication, and testing of low sidelobe level (SLL) Butler matrix-based beamformers is presented. The paper divided in two parts. first part deals with conventional technique simultaneous excitation input ports. second introduces some novel modified SLL matrices, as an alternative advantageous design choice. Circuit architecture makes use asymmetric branch line couplers able to provide high values output power division ratios. Radiation patterns SLLs far lower than...
Today there is an increasing request for high‐throughput communication payloads in satellite communications. Capacity the order of 100 Gbit/s becoming available and further significant improvement expected coming years. A key element to guarantee this high performance constituted by multibeam antennas, able generate multiple narrowly focused spot beams with frequency polarisation reuse. Direct radiating arrays are coverage a single aperture possibility reconfiguring power distribution among...
Water scarcity and desertification are considered to be among the greatest challenges of humanity over coming decades. Worldwide, agriculture accounts 69% total water usage, while industry for 23%, urban use 8%. In Greece, a rural development model poor farming practices have resulted in an overwhelming 83% consumption directed uses. Furthermore, excessive combined with existing pesticides fertilizers usage levels creates exponential problems cycle Greece. Taking into account above...
The current work proposes a direct rational function fitting method, employing cylindrical waves alone, for the accurate evaluation of Sommerfeld integrals planar multilayered structures. Three are key points effort. 1) Until now, relative works require extraction quasi-static/asymptotic terms, and branch cut/continuous wave contribution explicitly. In one, explicit treatment those terms is avoided. proposed methodology based on spectrum Green's by functions. Thus, it provides spatial solely...
A study of the maximally sparse large planar arrays with electrically elements is presented. The conditional probabilities element placements and their resulting auxiliary radiation integrals are derived. Through them average directivity pattern formulas also Employing these formulas, we present a convex method that provides solution to problem when main lobe constraints imposed on pattern. In particular, by taking possible types into account, manage obtain lower bound an array should...
The subject of this paper concerns the design and optimization a helical open waveguide structure for thermal tumor ablation with microwaves, treatment also known as MicroWave Ablation (MWA). A variety antennas MWA have been developed so far. However, most these cannot accurately control temperature field they produce. As result, heating extends to healthy tissues well. Therefore, first innovation proposed here is use that will distribution deposited electromagnetic power achieve total...
Butler Matrix networks are well established as beamforming for phased antenna arrays. The challenge we address in this work is to cover the entire (advanced 5G or 6G) FR3 band (7–24 GHz) with a single network, while retaining low losses and minimal size. employed multilayer topology also established; however, matching between utilized hybrid couplers phase shifters constitutes major such wideband operation. This achieved herein by employing meander lines appropriate curvature introducing two...
Although RFID(radio frequency identification) tags do not require a direct line of sight, their operational range is often characterized as being limited. Indeed, in the case passive RFID tags, interrogating signal from transmitter needs to reach tag's radio transponder and trigger nearly omnidirectional scattered be harvested by receiver. This two-way (from Tx tag back Rx) channel exhibits increased attenuation only due doubled distance (in Rx are collocated) but also uncontrolled (i.e.,...
A design procedure for the synthesis of planar arrays is presented. Synthesis takes into account desired pattern and constraint on directivity index. It makes use perturbation method in conjunction with Lagrange multiplier theory. Starting from an initial array we perturb element positions by employing iterative technique. In iteration, setting first variation Lagrangian (Cost function) equal to zero derive perturbed positions. Perturbation applied simultaneously along two independent...
In this article, the design of a cylindrical beamforming array (CBA) is presented. The conformed over ring conducting circular cylinder. From total number elements, M, array, subset N successive elements enabled each time. selection based on minimization angle between its broadside direction and arrival (DOA) signal interest (SOI). Furthermore, by adaptively combining outputs active subarray, gain system maximized. integrated into CDMA acquisition phase, where joint process code...
A deterministic method for the design of direct radiating arrays multibeam satellite applications is presented in current work. The embodies following steps: First, we consider problem continuous aperture synthesis, subject to directivity-pattern mask constraints. We succeed stating as a convex magnitude antenna that exhibits second-order cone program form. solution provides optimum current-density distribution. Second, exploiting solution, analytical formulas, form Pareto front, are through...
A geometry synthesis procedure for arrays by the help of orthogonal method (OM) is given in work at hand. We start from an initial array with a excitation and we perturb element positions combining iterative technique OM. The final position elements found last iteration where desired approximation pattern obtained. It noticed that our formulation does not give always successful outcome, since search can be trapped local minimum. Thus, issue comes suitable selection array. Cases uniformly...
An efficient numerical algorithm for the analysis of printed antennas on a dielectric coated circular cylinder is presented. The formulation employs spectral domain approach. Green's function evaluated via Olver's uniform asymptotic expansions. Fourier summation transformed into integration and part integral in closed form. whole procedure results that at least as accurate respective one planar structure. present approach can be applied any source-receiver position radius