Fog-related flight disruption is costing big international airports more than Rs 2.5 crores for each such event, while the traditional countermeasures, chemical seeding and thermal heating, are expensive, slow and environmentally damaging. This paper proposes the first field-validated airport fog dispersal autonomous UAV system that combines deep reinforcement learning with targeted UV-C photolysis technology. Conventional ways of fog dispersal take 30–45 min for runway clearance, cost Rs 15,000 per operation and produce 500 kg of CO2 emissions. These strategies evaporate fog droplets without tackling the condensation nuclei that are causing them and so the fog can quickly reform. We use a 4-UAV swarm with UV-C LED arrays (254 nm wavelength) for the degradation of hygroscopic aerosols which act as cloud condensation nuclei (CCN). Unlike thermal approaches that only evaporate droplets, our photolysis-based approach can reduce the efficiency of CCN by 35–45

Winter fogs at Amritsar Airport create significant operational challenges that disrupt flight schedules and impose substantial economic costs. When visibility falls below the CAT-II minimum of 350 m, the airport loses approximately EUR 25 million annually due to flight delays, diversions, and cancellations. This paper presents a simulation-based proof of concept demonstrating how bio-inspired UAV swarms can mitigate runway visibility challenges. The research centers on the Pigeon Feather Flight Path Optimization algorithm, which draws inspiration from three key features of pigeon feathers: the asymmetric vane structure that generates differential lift, the interlocking barbule system that enables coordinated movement, and the dynamic flexibility that allows real-time adaptation to environmental conditions. Through comprehensive simulations using MATLAB and ANSYS Fluent, the research demonstrates substantial potential for improvement. For a four-UAV configuration, the median fog clearance time of 9.5 plus or minus 2.4 min (with a 95

The persistent challenge of radiation fog at Amritsar Airport, exacerbated by smog from agricultural and urban pollutants, necessitates innovative solutions to enhance runway visibility. This study proposes an AI-optimized UAV swarm system integrated with UV-C radiation to disperse pollutant-laden fog and improve the runway visual range (RVR). By coupling MATLAB/Simulink (for simulating 6-DOF UAV dynamics) with ANSYS Fluent (for modeling fog microphysics), the framework employs deep reinforcement learning (DRL) to dynamically optimize swarm paths based on real-time LiDAR and RVR data. Results demonstrate that a 4-UAV swarm clears the fog in the Touchdown Zone (TDZ) within 5.06 min, achieving an 80

In the manuscript, a novel design of microstrip patch antenna with moderate degree of complexity is proposed in terms of metamaterial based unit cells as a radiating patch on the top as well as metamaterial based periodic structure as defected ground structure at the bottom (MRPMGS) for Intelligent Transportation System (ITS) applications. The novel design of patch antenna exhibited multi-bands with broad-band transmission patterns, improved high gain, high radiation efficiency, and compact structure. The MRPMGS has a three layered structure with overall dimensions of 32 mm x 28 mm x 1.6 mm. The top layer with radiating patch has unit cells with dimensions of 3.6 mm x 3.6 mm, and at the bottom the defective ground structure (DGS) has unit cells with dimensions of 4 mm x 4 mm. The middle layer is of an FR4 substrate with 1.6 mm thickness. The MRPMGS has experimental (simulated) transmission frequencies at 11.54 GHz (11.24 GHz), 12.91 GHz (12.98 GHz), and 13.20 GHz (13.48 GHz) with reflection coefficients of-20.91 dB (-25.16 dB), -26.19 dB (-29.36 dB), and-18.94 dB (-26.02 dB), respectively. The VSWR varies between 1 and 3. The radiation efficiency reaches 80%, and high gain varying between 2.35 and 5.5 is achieved at the desired frequencies.

A new design of C-shaped and Inverted C-shaped, multi-band metamaterial absorber (CICMBMMA) is discussed in the presented research paper. The proposed design of CICMBMMA consisted conventional three layers. At the top frequency selective surface it consisted of optimized 0.035 mm patches with C-shape and inverted C-shape embedded inside the square patch, copper metallic layer with a thickness of 0.035 mm is at the bottom, while the FR-4 substrate in the middle has a thickness of 0.8 mm. With measurements of 9 mm x 9 mm x 0.8 mm, the suggested CICMBMMA design is modelled in the CST microwave studio. For the CICMBMMA design, the simulated results revealed reflectance at 5.44 GHz, 17.44 GHz, 18.84 GHz, 27.12 GHz, 28.84 GHz, 33.04 GHz, and 34.20 GHz with coefficients of reflection -17.27 dB, -10.55 dB, - 23.44 dB, -27.71 dB, -32.59 dB, -32.59 dB, -20.90 dB, and -20.78 dB respectively. The uniqueness about the proposed design is that with only three different patches on the top layer it exhibited seven high absorptance bands with pair of bands merged to generate broad-bands lying within frequency range from 5 GHz - 35 GHz with potential applications in stealth technology, reducing RCS, absorption in 5G spectrum.

This chapter presents a comprehensive comparative analysis of unmanned aerial vehicles (UAVs), focusing on two critical aspects: payload capacity and performance. Payload capacity, which refers to the maximum weight a UAV can carry, directly influences the suitability of UAVs for specific applications such as aerial photography, surveillance, cargo delivery, and scientific research. Performance attributes, including flight range, endurance, speed, maneuverability, and altitude capabilities, collectively shape a UAV's operational envelope and effectiveness for diverse missions and environments. This chapter examines how different UAV models compare in terms of their payload capacities and performance characteristics. Key findings reveal significant variations in payload capacity among UAV models, ranging from a few hundred grams for small consumer drones to several kilograms or more for professional-grade UAVs. The comparative assessment also highlights the trade-offs inherent in UAV selection, as higher payload capacity may come at the expense of other performance attributes.

In recent years, metamaterials (MMs) have attracted researchers due to their geometrical and structural uniqueness that make these materials to absorb, block, and enhance electromagnetic (EM) waves, which is not possible with conventional materials found in nature. These artificially engineered materials derive the EM properties (effective values of permittivity ε∼eff and permeability μ∼eff less than zero) from the shape, size, orientation, and periodicity of unit cells rather inheriting those from material composition. The study on MMs has been diversified from the radio frequency range to the optical frequency range, with potential applications in realization of novel devices such as perfect lenses, EM, and MM based microwave patch antennas. For the past few years, the concept of MMs has been widely used to develop and design metamaterial perfect absorbers (MPAs). The proposed chapter mainly focuses on the classification of materials on the basis of permittivity and permeability; MPAs; applications of MPAs; experimental demonstrations of first single-band MPAs in microwave, THz, mid-IR and near IR regimes; conditions for complete absorption of EM waves; MPA as perfectly matched layer (PML); attenuation mechanism of EM waves inside the MPA; calculation of MM parameters; measurement and testing process, followed by a case study on multi-band MPA.

The artificially engineered materials termed as metamaterials (MMs) possess unnatural electromagnetic (EM) properties with μ < 0 and ε < 0 due to their geometrical and structural uniqueness. This resulted in diversified study of MMs from the GHz to THz range with one of the potential application as microwave absorber. In this chapter, a case study has been taken up with a unique design of a MM microwave absorber that exhibits multi-band as well as broad-band absorptance within 5GHz - 40GHz. The proposed structure consists of a square ring and a “+” shaped patch at its centre and the scaled “+” shaped patches at four corners. The proposed MM absorber exhibited absorptance peaks of 99.74%, 98.58%, 90.00%, 90.04%, 84.74%, and 94.94% at 6.33 GHz, 14.08 GHz, 28.92 GHz, 32.48 GHz, 33.84 GHz, and 37.69 GHz, respectively, with a broad-band lying within frequency range of 32 GHz to 37 GHz. The MM behavior is studied in terms of normalized matched impedance, effective permeability, and surface current distribution with potential application in stealth technology.

The manuscript presents a log-periodic microstrip antenna with a defective ground structure (LPMADGS). The antenna is simulated, designed, and validated for C-band applications. The design of the antenna consists of three layers with upper most layer consisting of log-periodic, copper patches with a thickness of 0.035 mm; the middle layer is a 2 mm thick dielectric layer of FR-4 substrate; and the bottom layer is a defected ground structure (concentric ring resonators of 0.035 mm thickness). The suggested antenna design is simulated with a complete ground plane, without ground plane, and with a defective ground plane. The proposed antenna with optimized design is fabricated by wet etched method. The simulated results are approximately similar to the experimentally measured results. The experimentally measured results show transmission peaks at 7.65 GHz and 7.90 GHz. The resonating effect of log-periodic patches with a defected ground structure results in wide-band of 0.91 GHz (−10 dB bandwidth). The proposed antenna structure exhibits a wide bandwidth transmission which mostly resonates in frequency range that lies in C-band. It has future applications for mobile as well as wireless communication.

Abstract A new design of an ultra wide-band metamaterial absorber (MMA), with appreciable high absorptance insensitive to angle of incidence and polarization angle is presented in the manuscript. The MMA structure consists of three concentric rings with non-linear variation in the spacing and the thickness of the rings is controlled by a single parameter. The idea of utilizing nonlinear variation based unit cell resulted in high absorptance ultra wide-band frequency spectrum in X -band. The proposed MMA design is three layered structure. The metamaterial nature of the proposed device is explained by simulated values of Z eff( f ), μ eff( f ), ε eff( f ), and η eff( f ). The FWHM bandwidth of proposed MMA is 6.32 GHz (7.36 GHz-13.68 GHz). The fabricated MMA is ultra-thin with thickness of λo/15.3 at centre frequency 9.8 GHz. The experimental results show absorptance greater than 99% at 7.9 GHz and 11.7 GHz, covering entire X -band range makes this MMA appropriate for providing stealth technology for defense equipments by reducing radar cross section (RCS).

A new design of wide-band, co-planar waveguide (CPW) fed, rectangular patch antenna loaded with continuous ring resonators (RPACRR) is proposed for C-band. The proposed RPACRR design consisted top layer of optimized rectangular patches of copper with 0.035 mm thickness, middle layer of FR-4 substrate of thickness 2 mm and the bottom layer of concentric continuous ring resonators (CCRRs) of 0.035 mm. The proposed RPACRR design with dimensions 33.30 mm × 20.22 mm × 2 mm is simulated in two different configurations, with CCRRs and without CCRRs. The simulated results for RPACRR design showed transmission peaks at 3.9 GHz and 5.4 GHz with reflection coefficients of -15.42 dB and -23.01 dB simultaneously. The uniqueness in the design is CPW line, consisting of rectangular patches and replacement of ground patch layer with patches of CCRRs that act as defective ground layer. The combined resonance effect of patch antenna backed by CCRRs resulted in broad-band of 3.53 GHz. The proposed RPACRR design exhibited broad-band transmission band-width that resonates at frequencies lying in C-band with potential application in wireless communication.

A new design of a metamaterial absorber (MMA) with two broad-bands is simulated, fabricated and experimentally investigated in this paper. The MMA structure unit cell consists of combination of eight rings with two pair of concentric split rings and two pair of concentric continuous rings placed diagonally opposite. The proposed MMA has x-y symmetrical copper unit cells with middle layer of FR-4 substrate and copper laminated ground plane. The simulated and measured absorption peaks as well as the absorptance of the proposed MMA exhibits insensitivity to change in polarization and incidence angle of electromagnetic waves. The metamaterial behavior of the studied MMA is confirmed by extracting effective permeability, mu(eff)( f), effective permittivity, epsilon(eff) (f), and effective refractive index, eta(eff)(f), from the measured S-parameters. The proposed MMA has resonance peaks at 7.6 GHz, 8.9 GHz, 12.3 GHz, and 12.8 GHz with measured absorptance of 94%, 99.9%, 96%, and 96% at respective frequency bands. The first absorption broad-band extends from 7.36 GHz to 9.36 GHz and the second broad-band extends from 11.9 GHz to 13 GHz. The high electromagnetic wave absorptance from 7.36 GHz-9.36 GHz and 11.9 GHz-13 GHz makes this MMA suitable for satellite, mobile and radar applications.

Simulation and experimental measurement of a new design of an oblique incidence and polarization insensitive metamaterial absorber with multiband absorption is presented in this paper. The unit cell of the proposed metamaterial absorber comprises concentric continuous rings of different radii and widths placed in four different quadrants with identical pair of rings placed diagonally opposite, with each ring responsible for high absorption. The calculated dispersion behavior of MM absorber in terms of effective permittivity (epsilon(eff)), effective permeability (mu(eff)), and refractive index (eta(eff)) shows the metamaterial characteristics. The surface current and field distributions in MM absorber are simulated to understand the occurrence of absorption bands. The measured results show the absorption peaks of 99.5%, 99.8%, 99.5% and 99.9% at 7.20 GHz, 9.3GHz, 12.61 GHz, and 13.07 GHz, respectively. The simulated results are well supported by the experimentally measured performance of the fabricated metamaterial absorber. It offers multiband absorption with bands lying in C-band, X-band and Kuband for mobile communication, satellite communication and radar applications. With merged third and fourth absorption peaks, the proposed metamaterial absorber structure exhibits a broadband absorption.

This paper presents the design, simulation and parametric analysis of a concentric continuous and split rings resonator (CCRR, CSRR) structure for a dual broadband metamaterial (MM) absorber. The MM structure unit cell consists of concentric circular split rings of same width and different radii and concentric continuous rings of different width and different radii arranged in four different quadrants. The three layered proposed MM absorber design has upper layer comprising of concentric continuous and split rings structured sub-cells separated by bottom laminated copper layer of FR-4 substrate. The proposed MM absorber is insensitive to any polarization state of incident EM waves due to highly symmetrical circular and split ring structures. The scattering parameter and absorption coefficient are obtained for the present MM absorber. The magnetic and electric fields are monitored to realize the behavior of MM structure. The dual broadband MM absorber has absorbance of 99% from 7.785 GHz - 8.475 GHz and absorbance of 98% from 11.835 GHz - 12.81 GHz. The absorption peaks for this MM absorber are obtained as 99.5%, 99.6%, 98.4% and 98.8% at 7.785 GHz, 8.475 GHz, 11.835 GHz and 12.81 GHz frequencies respectively for the normal incidence of EM waves. The high absorbance makes this MM absorber suitable for various microwave applications including airborne and radar signal absorption.

Low density parity-check code (LDPC) is an error correcting code used in noisy communication channel (e.g. AWGN) to reduce the probability of error in information. By using LDPC codes, this probability can be made comparatively small, so that the data transmission rate can be as close to Shannon's limit. The decoding of Low Density Parity Check (LDPC) codes by iterative process of belief propagation gives challenges for designers looking for real time performance in communication systems. This thesis work proposes the use of Artificial Neural Networks (ANN) to replace belief propagation to approach closer to Shannon's limit more closer than other traditional decoding methods. This thesis is intended to design a new methodology to decode LDPC codes in Non-iterative manner with the help of ANN and Look Up Table (LUT). This work is at initial stage and will be extended for better performance.