Abstract In this work, we investigated the path loss (PL) profile of the outdoor radio channel in the 800 MHz band for the Icaraí region in the city of Niterói. This frequency band has recently been reserved by the brazilian National Telecommunications Agency (ANATEL) for utilization in Public Protection and Disaster Relief (PPDR) wireless networks, and Icaraí constitutes a potential area to receive coverage provided by a PPDR network whose implementation is of interest to the Niterói government. The investigation relies on narrowband large scale measurements, recorded at various places throughout the neighborhood. As a theoretical framework for the analysis, we consider four log-distance PL models, which have been widely used in recent outdoor channel sounding works. Our findings seek to facilitate the successful establishment and optimization of PPDR networks in Niterói city. work (PL 80 ANATEL (ANATEL (PPDR government measurements neighborhood analysis logdistance log distance models works 8

Abstract This paper delves into the realm of Electromagnetic forming (EMF), a high-speed forming process leveraging pulsed magnetic fields generated via capacitor bank discharge through a coil. Traditionally, numerical analyses of EMF processes focused on electromagnetic tube expansion and the influence of forming conditions. However, in high-energy electromagnetic setups, the magnetic field concentrator adds complexity, transitioning analyses into a 3D modeling domain. This paper consolidates an analysis and numerical investigation inspired by the Muhlbauer approach to elucidate the impact of the field concentrator on electromagnetically expanded tubes. Employing an enhanced finite element model for magnetic tube expansion simulations. This research sheds light on how this additional component influences the EMF process, offering valuable insights into modeling electromagnetic bulging when incorporating the field concentrator. EMF, , (EMF) highspeed high speed coil Traditionally conditions However highenergy energy setups complexity D domain tubes simulations (EMF

Abstract The study proposes a multidimensional mathematical modeling of antennas using coaxial cables for 5G, with emphasis on the relationship between cable length, frequency, and VSWR. By employing a final configuration incorporating five circular slots of 6 mm and operating at a frequency of 3.5 GHz, a linear pattern in this relationship was identified. Despite the recognized challenges in accurately modeling VSWR concerning cable length, the study enabled antenna optimization through the determination of the proposed antenna’s properties and their respective mathematical correlations. 5G G length 35 3 5 3. GHz identified s correlations

Abstract In this work, a reconfigurable frequency-selective surface (FSS) with a very simple biasing network that offers singleor multi-band response is presented. The proposed structure is formed by the V-shaped elements on a single-sided dielectric substrate. A PIN diode is used as active device to make the FSS reconfigurable, and bias lines are inserted for feeding. Initial analysis is performed with passive FSSs to predict the behavior of the proposed reconfigurable structure. The proposed reconfigurable FSS is then designed and evaluated. Three biasing-state configurations are analyzed: off-state, on-state, and intermediate-state. Depending on the state applied to the FSS, it can exhibit single switchable resonance frequency or multi-band response with a Fano resonance. work frequencyselective selective (FSS multiband multi band presented Vshaped V shaped singlesided sided substrate feeding evaluated biasingstate analyzed offstate, offstate off state, off-state onstate, onstate on-state intermediatestate. intermediatestate intermediate state. intermediate-state

Abstract This work proposes the integration of a monopole antenna with a frequency selective surface (FSS) with double square loop geometry, which operates in the ISM (2.4 - 2.4835 GHz) and IEEE 802.11 WLAN (5.15-5.725 GHz) bands. The FSS was developed to be integrated into a microstrip monopole antenna, aiming to improve some of its radiative features, such as gain, directivity, and front-to-back ratio (FBR). We show that the double square loop FSS operates in bands from 1.91 to 3 GHz and from 4.64 to 6.56 GHz, fully covering the bands of interest. A prototype of the proposed structure was assembled and both the numerical simulation and the experimental results show that the antenna integrated with FSS presents significant improvements in all parameters, compared to the antenna without FSS. Because of the interest frequency ranges the proposed structure can be applied in non-invasive biomedical applications. (FSS geometry 2.4 24 2 4 (2. 24835 4835 2.483 80211 802 11 802.1 5.155.725 5155725 5.15 5.725 5 15 725 (5.15-5.72 features gain directivity fronttoback front back FBR. FBR . (FBR) 191 1 91 1.9 464 64 4.6 656 6 56 6.5 parameters noninvasive non invasive applications 2. (2 2483 483 2.48 8021 80 802. 155 5.155.72 515572 515 5.1 5725 5.72 72 (5.15-5.7 (FBR 19 9 1. 46 4. 65 6. ( 248 48 8 5.155.7 51557 51 5. 572 5.7 7 (5.15-5. 5.155. 5155 57 (5.15-5 5.155 (5.15- (5.15 (5.1 (5. (5

Abstract The technique of electromagnetic characterization of materials in free space allows for the measurement of constitutive properties without making contact with the material being measured. Characterization methods in Free Space are naturally suited for Electromagnetic Radiation Absorbing Materials (RAM) but are also important in applications where the material sample to be measured does not undergo major interventions. They consist of evaluating a received signal resulting from a free-space transmission through two horn antennas with beam collimating lenses and a Vector Network Analyzer (VNA). The characteristics of the transmitted signal are modified by a material positioned between the transmitting and receiving antennas. This work presents methods for electromagnetic characterization in Free Space, in the frequency range of 8.2 to 12.4 GHz (X-Band), in a semi-anechoic chamber, seeking the development of measurement processes that present results with repeatability and reliability. The measurements were made with standard and electromagnetic radiation absorbing materials. The measurement technique presented 95% of efficiency. RAM (RAM interventions freespace VNA. VNA . (VNA) 82 8 2 8. 124 12 4 12. XBand, XBand X Band , (X-Band) semianechoic semi anechoic chamber reliability 95 efficiency (VNA 1 (X-Band 9

Abstract A novel planar balanced-to-balanced (BTB) microstrip filtering crossover with high isolation and common-mode (CM) suppression is proposed in this paper. The circuit structure is based on microstrip transmission lines without coupling sections, which can reduce insertion loss and enhance isolation. Specific theoretical analysis of the BTB filtering crossover configuration using transfer matrix and mixed-mode scattering parameters is performed. In order to verify the validity of the theory analysis and design, a microstrip BTB filtering crossover prototype at the center frequency of 2.45 GHz is fabricated and measured with high isolation and excellent CM suppression. balancedtobalanced balanced (BTB commonmode common mode (CM paper sections mixedmode mixed performed design 245 2 45 2.4 24 4 2.

Abstract To obtain a long propagation length and a small effective mode area, a new hybrid plasmonic waveguide model is proposed. We design a hybrid plasmonic waveguide composed of chiral metamaterials, silver metal at its center, and surrounded by a graphene interface using the COMSOL environment based on the finite element method. The interface thickness is 1.02nm, where three monolayer graphene were used. The waveguide properties can be achieved with the range of radius 5-60 nm, chemical potential 0.1-1 eV, and refractive index of metamaterial is -3 within the wavelength used. Moreover, we obtained a long propagation length, a small effective mode area, high power confinement, and lower loss. The results showed that the presence of graphene positively affects the waveguide properties, while increasing the chirality parameter, K, does not have a good effect. At the chemical potential 1eV, the propagation length will be 2.45mm in the absence of chirality, while it equals 0.4mm at K=1 with the used wavelength 1.55μm. area proposed metamaterials center method 102nm nm 1 02nm 1.02nm 560 5 60 5-6 0.11 011 0.1 0 0.1- eV 3 - Moreover confinement loss parameter K effect 1eV 245mm mm 2 45mm 04mm 4mm K1 K= 155μm μm 55μm 1.55μm 56 6 5- 11 01 0.

Abstract Resource allocation strategies in optical networks are fundamental due to bandwidth limitations, increasing data demand, and the consequent need for spectral efficiency. They allow for improving optical spectrum usage and ensure flexibility in the face of the dynamic nature of traffic and the coexistence of different services, reducing costs and contributing to the system’s reliability. In this context, this work proposes a resource allocation strategy that combines power assignment with spectrum allocation. Power assignment is done by launching the minimum required power plus a margin according to the route’s state. Meanwhile, spectrum allocation is performed through a modified version of the Min Slot Continuity Capacity Loss (MSCL) heuristic, capable of finding a set of frequency slots in a route, which results in minor allocation capacity loss. The choice of the MSCL algorithm was motivated by the possibility of increasing spectral efficiency through the reduction of physical layer penalties and the reduction of spectrum fragmentation by combining freedom degrees: launch power of light, modulation, route, and spectrum. The developed heuristic was tested on two networks with distinct characteristics and compared with two reference approaches. The results demonstrated a significant superiority in terms of reducing the blocking probability. limitations demand services systems system s reliability context routes route state Meanwhile (MSCL loss degrees light modulation approaches probability

Abstract This paper presents a novel design of an X-band (812 GHz) 4-bit monolithic microwave integrated circuit (MMIC) type true-time-delay (TTD) line for wideband high-resolution imaging radar applications. The designed TTD line circuit offers a maximum time delay of 920 picoseconds (ps) using eight 115 ps delay elements and a distributed switching network. The unit delay line is synthesized using an artificial transmission line (ATL) circuit and implemented in a compact form of 18.5 mm2 using 130 nm gallium arsenide (GaAs) pseudomorphic high-electronmobility-transistor (p-HEMT) technology. The size of the switches and characteristic impedance of the transmission lines have been optimized to minimize insertion loss variation across different delay states while maintaining a flat delay response over a wide bandwidth. A basic 115 ps delay line cell is fabricated to prototype the circuit using GaAs-based MMIC processes. The final 920 ps chip layout simulation exhibited input and output return loss of better than 10 dB, insertion loss of 28±2 dB, and group delay variation of ±10 picoseconds over a 4 GHz bandwidth. Xband X band 812 (81 4bit bit (MMIC truetimedelay true (TTD highresolution high resolution applications 92 (ps 11 network ATL (ATL 185 18 5 18. mm 13 GaAs (GaAs highelectronmobilitytransistor electronmobility transistor pHEMT p HEMT (p-HEMT technology bandwidth GaAsbased based processes 1 dB 282 28 2 28± ±1 81 (8 9 ± 8 (

Abstract This paper will propose an innovative compact, low-cost, low-profile inverted U-shaped patch antenna with a single and dual band-notched ultra-wideband (UWB) with split ring resonators (SRRs). To achieve our main goal based on the reduction of electromagnetic interference in narrowband communications (WLAN, WiMAX, and satellite), four-element rectangular split-ring resonators (SRRs) array are placed nearby the feedline to create notch band at approximately 5.15-5.35 and 5.725-5.85 GHz. The SRRs antenna's measured data indicate a directivity of 8.52 dBi, a gain of 7.18 dBi, a reflection coefficient of -27 dB, and an efficiency of 84.3%. The realized prototype, including the SRRs and CSRRs structures, were carried out using a PCB prototyping machine. Reflection coefficient measurement is obtained using a vector network analyzer (VNA) PNA-X from Agilent Technologies. The measured values of the proposed antenna, with 50 x 38 x 1.6 mm3 in total and constructed on a FR4 substrate with permittivity of ɛr = 4.3, loss tanδ = 0.0024 and substrate thickness of h = 1.6 mm, correlate well with the simulated values. The proposed antenna, compared with other published work, is a good candidate to operate in WLAN, X-band. compact lowcost, lowcost low cost, cost low-cost lowprofile profile Ushaped U shaped bandnotched notched ultrawideband ultra wideband UWB (UWB SRRs. . WLAN (WLAN WiMAX satellite, satellite , satellite) fourelement four element splitring (SRRs 5.155.35 515535 5.15 5.35 5 15 35 5.15-5.3 5.7255.85 5725585 5.725 5.85 725 85 5.725-5.8 GHz antennas s 852 8 52 8.5 dBi 718 7 18 7.1 27 -2 dB 843 84 3 84.3% prototype structures machine VNA (VNA PNAX PNA X Technologies 16 1 6 1. mm FR 43 4 4.3 00024 0 0024 0.002 work Xband. Xband band. X-band 155 5.155.3 51553 515 5.1 535 5.3 5.15-5. 7255 5.7255.8 572558 5725 5.72 585 5.8 72 5.725-5. 8. 71 7. 2 - 84.3 4. 0002 002 0.00 5.155. 5155 51 5. 53 5.15-5 5.7255. 57255 572 5.7 58 5.725-5 84. 000 00 0.0 5.155 5.15- 5.7255 57 5.725- 0.

Abstract This paper presents a study on Active Frenquency Selective Surface (AFSS) for applications in modern wireless communication systems. Initially, an FSS with an element inspired by convoluted metallic lines printed on a dielectric substrate of FR-4 is proposed. The unit cell size is equal to 10.2 % of the wavelength in free space for the frequency of 1.53 GHz. An equivalent circuit model is proposed to better understand the operating principle of the FSS. Four Schottky diodes have been inserted in a symmetrical manner for switching, and three operating states are analyzed (all diodes in off state, all diodes directly polarized and therefore conducting, and two diodes conducting and two diodes off). The reconfiguration allows the frequency response to vary between frequencies from 0.8 GHz to 2.5 GHz. The FSS proved to be stable with respect to the angle of incidence of the plane wave on the circuit surface. The simulated numerical results for the designed prototype was obtained by ANSYS HFSS software. The prototype was built and the experimental characterization of the transmission coefficients, bandwidth and resonance frequency was performed. The values obtained in the experiment were compared and discussed with the simulation results, which showed good agreement. AFSS (AFSS systems Initially FR4 FR 4 FR- 102 10 2 10. 153 1 53 1.5 switching state off. . off) 08 0 8 0. 25 5 2. surface software coefficients performed agreement 15 1.

Abstract This paper presents a numerical study and the optimization of very short discrete multi-pump Raman amplifiers using Tellurite-based optical fibers. While most studies about discrete Raman amplifiers usually focus on cases where hundreds of meters of fiber are used, here we consider a multi-pumped Raman amplifier setup with extremely short dimensions, in which the length of the gain media was varied from 2.5 to 30 meters. The optimization process was developed over an broad amplification band from 1520 to 1600 nm, considering a maximum acceptable ripple of 3 dB, and using 2, 3 and 4 pumps with individual powers always below 2.5 W. The results show that it is possible to achieve net gains as high as 10 dB for gain media around 20 meters, and close to 15 dB for 30 meters. These high gains highlight the fact that Tellurite-based optical fibers can be used for the construction of very short and compact broadband amplifiers using just a few pump lasers with modest optical powers. multipump multi Telluritebased Tellurite based multipumped pumped dimensions 25 2 5 2. 152 160 nm W 1 16

Abstract A novel wideband high-selectivity substrate-integratedwaveguide (SIW) filtering antenna with controllable radiation nulls is proposed. This antenna is composed of a two-layered SIW resonator, two radiating slots on the top layer, and two coupling slots on the middle layer. A vertical SMA connector is located at the bottom and feeds two SIW cavities simultaneously. By adjusting the parameters of these slots, three radiation nulls will be achieved, and two radiation nulls can be easily controlled. For demonstration, one prototype of the filtering antenna is fabricated and measured. Measurement results show that the fractional bandwidth for |S11| < -10 dB is 8.9% (3.86-4.23 GHz), the gain is 6.08 dBi at center frequency 4.05 GHz, three radiation nulls are achieved at 3.7 GHz, 4.3 GHz, and 5.19 GHz, respectively. The out-of-band skirt selectivities of two sidebands are 150 and 332 dB/GHz, respectively. highselectivity high selectivity substrateintegratedwaveguide substrate integratedwaveguide (SIW proposed twolayered layered resonator layer simultaneously controlled demonstration measured S11 S |S11 10 -1 89 8 9 8.9 3.864.23 386423 3.86 4.23 3 86 4 23 (3.86-4.2 GHz , GHz) 608 6 08 6.0 405 05 4.0 37 7 3. 43 4. 519 5 19 5.1 respectively outofband out band 15 33 dBGHz dB/GHz S1 |S1 1 - 8. 864 3.864.2 38642 386 3.8 423 4.2 2 (3.86-4. 60 0 6. 40 51 5. |S 3.864. 3864 38 42 (3.86-4 3.864 (3.86- (3.86 (3.8 (3. (3 (

Abstract In this article, a comprehensive analysis of the approach known as Split-Step Wavelet Parabolic Equation (SSW-PE) in modeling radio wave propagation is presented. The SSW-PE introduces innovations, such as the application of narrow-angle and wideangle approaches, referred to as NAPE and WAPE, respectively. Furthermore, the SSW-PE demonstrates the incorporation of refractivity variations, modifications in terrain modeling for better representation, and considerations of surface boundary conditions. In addition to its innovative aspects, this study aims to provide a complete guide for effectively replicating the algorithm, thereby promoting the advancement of propagation studies using wavelets. The effectiveness and applicability of this approach are validated through comparative studies with well-established solutions, including the Discrete Mixed Fourier Transform (DMFT) version of the Split-Step Parabolic Equation (SSPE) method. Comparisons with measurements from real propagation cases are also conducted. Statistical analysis confirms the innovative potential of the SSW-PE algorithm, which also offers computational efficiency for rapid and consistent simulations. Thus, this article contributes to a comprehensive and innovative analysis, providing tangible resources for the research community interested in expanding this methodology. SplitStep Split Step SSWPE SSW PE (SSW-PE presented innovations narrowangle narrow angle approaches WAPE respectively Furthermore variations representation conditions aspects algorithm wavelets wellestablished well established solutions DMFT (DMFT SSPE (SSPE method conducted simulations Thus methodology