arXiv subjects

Hamed Saghaei

Publications and source records attributed to Hamed Saghaei.

6 recordsLinked to original sources

arXiv2024

Design and Analysis of Pseudospin-Polarized Ultra-Wideband Waveguide Supporting Hybrid Spoof Surface Plasmon Polaritons

In this study, novel low-loss waveguides and power dividers for ultra-broadband surface plasmon polaritons (SPPs) are introduced. This article uses complementary metasurfaces in place of traditional SPP, which are typically produced as metasurface unit cells on the dielectric sublayer. It has been demonstrated that the use of complementary metasurfaces considerably improves wave confinement and inhibits wave propagation. Because of this, it is anticipated that waveguides and power dividers made from these complimentary unit cells will have significantly lower losses and greater bandwidth than SPP used in traditional devices. In the frequency range of 0 GHz to 100 GHz, waveguides and bent waveguides with complementary metasurface unit cells exhibit insertion loss greater than 0.5 dB. Utilizing complementary metasurfaces, symmetric and asymmetric power dividers have been created and researched. The results of the simulation have shown that using this type of unit cell in the construction of microwave devices is advantageous.

physics.optics↗

arXiv2020

A novel design of all-optical half adder using a linear defect in a square lattice rod-based photonic crystal microstructure

In this paper, we propose an all-optical high-speed half adder based on linear defects in a photonic crystal (PhC) structure composed of silicon rods. The proper design of half adder results in no need to increase the intensity of the input optical signal for the appearance of the nonlinear Kerr effect, which leads to diverting the incoming light toward the desired output. The proposed device consists of four optical waveguides and a defect in a square lattice PhC. Two famous plane wave expansion and finite difference time domain methods are used to study and analyze photonic band structure and light propagation inside the PhC, respectively. The presented structure, the ON-OFF contrast ratios for Sum and Carry, are 16dB and 14dB, respectively. Our simulation results reveal the proposed half adder has a maximum delay time of 0.7 ps with a total footprint of 158 um2. Due to very low delay time, high contrast ratio, and small footprint that they are more crucial in modern optoelectronic technologies, this structure can be used in the next generation of all-optical high-speed central processing units.

physics.optics↗

arXiv2019

A Comparative Study of Multipole and Empirical Relations Methods for Effective Index and Dispersion Calculations of Silica-Based Photonic Crystal Fibers

In this paper, we present a solid-core Silica-based photonic crystal fiber (PCF) composed of hexagonal lattice of air-holes and calculate the effective index and chromatic dispersion of PCF for different physical parameters using the empirical relations method (ERM). These results are compared with the data obtained from the conventional multipole method (MPM). Our simulation results reveal that the ERM is an accurate and fast method for dispersion analysis of PCFs with large pitch sizes. However, for small pitch sizes of PCFs, it is not as accurate as the MPM method. Therefore, ERM is a fast, simple and accurate method for modeling and analysis of Silica-based PCFs with large pitch sizes.

physics.app-ph↗

arXiv2016

Design and Implementation of a Fleet Management System Using Novel GPS/GLONASS Tracker and Web-Based Software

Knowing where the vehicles are, what the drivers doing and monitoring every event in real time is the key parameters for a well-managed decision-making process. In this paper, a novel approach for control and monitoring of a fleet management system using three elements including GPS/GLONASS-based automatic vehicle locators (called Rad100), GPRS/SMS GSM cellular network and web-based software (called PayaRadyab) is proposed to show exact position of the desired vehicle on different maps and take detailed reports of the mission, travelled path, fuel consumption rate, speed limits, and other necessary information according to the customers requests. The most significant features of the proposed system are its global covering, high accuracy of positioning, easy operation by the user at any location, and easy energy management. In this study, I have designed and fabricated more than 50 Rad100 trackers and also programmed a web-based PayaRadyab software in which their performance and accuracy have been confirmed by the practical results in different conditions.

cs.CY↗

arXiv2012

A Novel Architecture for Antenna Arrangement in Wireless Cellular CDMA Systems

Wise arrangement of antennas is critical in wireless cellular systems for both reduction of co-channel interference (CCI) and increase the quality of service (QoS). In this paper, a novel architecture for antenna arrangement in CDMA wireless cellular systems is presented. In this architecture that we called microzone, every cell is divided into three (or more) zones and information transmission in downlink channel is done by an antenna which is placed at the outer region of the related zone. Also, the transmitting signal by the mobile station (MS) in uplink channel is received by all antennas of the related cell. Analytical calculations of the received signal to noise ratio (SIR) and outage probability for both microzone and used architectures show that proposed architecture has better performance in compared with the used architecture. Also, simulation results confirm lower outage probability in uplink channel for microzone architecture.

cs.NI↗

arXiv2010

A model for semantic integration of business components

Today, reusable components are available in several repositories. These last are certainly conceived for the reusing However, this re-use is not immediate; it requires, in the fact, to pass through some essential conceptual operations, among them in particular, research, integration, adaptation, and composition. We are interested in the present work to the problem of semantic integration of heterogeneous Business Components. This problem is often put in syntactical terms, while the real stake is of semantic order. Our contribution concerns a model proposal for Business components integration as well as resolution method of semantic naming conflicts, met during the integration of Business Components.

cs.SE↗