The Adverse Effect of Electromagnetic Radiation From Cellular Base Stations in Nigeria

On a global scale, the telecommunication industry is experiencing tremendous growth in mobile phones. Mobile phones communicate with base stations that are erected by the telecommunication industry. The base station produces radio frequency and exposes the people near the base stations to radiation. The effect of electromagnetic radiation from four base stations located at the residential area was studied by measuring their electric field strength and calculating their magnetic field strength and power density at different distances covering a frequency range of 900MHz to 2100MHz. The obtained values showed that the four cellular base stations are operating above the standard values of the International Commission on Non-Ionizing Radiation Protection Electromagnetic Field Radiation. The specific absorption rate was measured to determine the amount of radio frequency electromagnetic radiation absorbed by the human body. The result which is in the range of 3.22-3.70 W/kg is higher than the acceptable 2 W/kg for localized specific absorption rate.

Comparative Study of Transmission Line Junction vs. Asynchronously Coupled Junction Diplexers

A conventional diplexer with a T-junction transmission line is designed in this work and compared with a new approach of designing a diplexer using the asynchronously coupled resonant junction (ACJ). The use of ACJ is to explore its features associated with enhancing the output response of the diplexer as well as its ease in control and implementation of the external couplings at the common port of an all-resonator-base diplexer. The measured and simulated responses of the diplexers were compared, and they agreed with each other.

Non-Reciprocal Series-Fed Microstrip Patch Antenna Array Based on Graphene-Black Phosphorus for THz Applications Using the Iterative Method

Two-dimensional materials have already demonstrated their potential in electronic applications. In this chapter, the authors propose and investigate a non-reciprocal series-fed microstrip patch antenna array based on graphene-black phosphorus for THz applications. The modeling and simulation of this structure are made with the wave concept iterative process method, in which the 2D materials are incorporated as conductive surface boundaries. Combining the advantages of graphene and BP, the antenna exhibits both strong anisotropic and plasmon responses that are not available in either individual graphene or black phosphorus layer. The authors envision that this strategy of hybridization of graphene and BP may pave the way towards non-reciprocal plasmonic components with enhanced functionalities at THz band with important applications in imaging and communications.

Development of Solar-Powered Microcontroller-Relay-Based Control System Omnidirectional Wheelchair

A solar-powered omnidirectional wheelchair is implemented for physically challenged persons. The framework was mounted on the wheels that were connected with two direct current (DC) motors. The ratings of the battery and solar module were determined using system voltage (12V). A 7,805-voltage regulator was used to supply 5VDC to the AT89352 microcontroller. The microcontroller was programmed to provide a reference signal to the motor. The motor provides the needed torque to drive the wheels through interconnected relays. The relays are energized by the microcontroller and omnidirectional movement achieved through relays connected with microprocessor and micro switches, eliminating the need for joysticks and complex control mechanisms. System performance test result showed that the auxiliary solar power supply of the wheelchair increased the travel range by approximately 86% compared with that of a wheelchair powered by battery alone.

Implementations of ACJ Technique in Different Four-Port Filter Networks

This chapter proposes the use of asynchronously coupled-resonator junctions (ACJ) in the design of a multi-input multi-output (MIMO) filtering network and a masthead combiner (MHC). By employing the resonator junctions, miniaturised circuits are achieved without using any transmission-line-based impedance matching circuits. The main challenge in the designs is the control and implementation of the external couplings at the common ports of this all-resonator-based MIMO filtering network and MHC. Both devices are four ports-based with the MIMO filtering network operating at 1.8, 2.1, and 2.6 GHz, while the MHC operates at the two channels of 1.8 and 2.1 GHz. The demonstrated designs achieved fractional bandwidths of 1.764 GHz to 1.836 GHz, 2.058 GHz to 2.142 GHz, and 2.548 GHz to 2.652 GHz, respectively. Good agreements have been achieved between the measurements of the prototype devices and the simulations.

The Changing Global Landscape With Emerging Technologies and Their Implications for Smart Societies

The opportunities offered by digital technology are enormous. The global social and economic system is being reconfigured at an incredible rate. Connectivity is increasingly reshaping our world and redefining the way we interact with our environment. The rise of digital technologies is transforming almost every aspect of modern life. More and more of our interactions are mediated by machines. Along with the rapid evolution comes the risks, threats, and vulnerabilities in the system for those who plan to exploit it. In this chapter, firstly, the authors explore the role of 5G, big data, the internet of things (IoT), artificial intelligence (AI), autonomous vehicles (AV), and cloud computing play in the context of smart societies; secondly, they analyse how the synergy between these technologies will be used by governments and other stakeholders around the world to improve the safety of citizens albeit increasingly relinquishing privacy rights and encouraging mass surveillance at the expense of liberty.

Ontology-Based Travel Recommender System

Recommender systems are designed to suggest information to users according to their preferences. The items could be movies, books, or various kinds of products. Most of the existing recommender systems are based on a database with limited advantages. However, in this chapter, the authors propose a knowledge-driven travel recommender system to integrate semantic data built using web ontology language (OWL) ontology to allow users to find suitable destinations that fulfil users' travel preferences. This work aims to develop a travel recommendation tool and to examine the reliability, the usability of the system, and satisfaction rate of users. They are also able to demonstrate that users can obtain desired results through queries on the ontology-based system. The overall evaluation of the system shows that users are happy and satisfied with the recommendation results.

Development Electronic Design Automation for RF/Microwave Antenna Using MATLAB GUI

This chapter presents the development of a user-friendly MATLAB-based electronic design automation (EDA) tool for RF/microwave antenna design. The development steps of EDA using MATLAB ‘guide' and MATLAB ‘appdesigner' design environments have been explained in detail. In this chapter, seven EDAs of different antennas are developed and described. The EDA is capable of predicting the dimensions of the antenna by inputting the desired operating specifications of the antenna, such as operating frequency. The rigorous analytical formulations that are implemented in this EDA are briefly described. The developed EDAs have simple and standalone guide user interface (GUI) display and fast program running time compared to iterative solution or numerical-based EDAs. The developed EDAs can be packaged and accessed either as standalone desktop app or web app. The accuracy of the EDA output results is validated by comparing to measurement and simulation results obtained from a commercial simulator.

5G and Unmanned Aerial Vehicles (UAVs) Use Cases

In the past few years, UAVs have evolved considerably towards real-world applications, going beyond entertaining activities. The unique features that UAVs can provide, such as flexible and easy deployment, high mobility, and mostly autonomous operation, tend to be appealing solutions in a wide variety of applications. With the number of UAVs expected to increase significantly in the forthcoming years, it is deemed mandatory to integrate innovative features of communication technologies in order to tackle several limitations and challenges that exist to date. To this end, the amalgamation of UAVs and 5G cellular networks is an auspicious solution in order to realise the full potential that the UAVs can provide as well as to effectively open up new fields of applications. The unique features that 5G cellular networks offer are utilised for supporting and providing reliable and secure UAV command and control. This chapter provides an overview of the 5G technology to support communication services for the UAV ecosystem.

Investigating the Effects of Temperature, Paste Height, and Time on Solder Paste to Its Printing Performance

Due to pressure to meet consumer requirements, miniaturization, reliability, and increased functionality have become more important. To achieve good assembly of electronic devices, there must be smooth deposition of tiny and consistent paste deposits on the board which must be up to an acceptable height and volume based on desirable process parameters in the output. The printing performance of the solder paste is dependent on conditions such as paste deformation behavior, good paste roll, complete aperture filling, and paste release onto the substrate pads. Eighteen tests were performed using two types of lead-free solder paste. Three temperatures were investigated under three different time intervals. Results analysis showed that variability of the paste distribution was lowest and more uniform for paste stored at 25˚C for 48 hours. From the analysis, it is obvious that temperature has tremendous effects on the printing performance of solder paste. This study recommends 25˚C as a good temperature for solder paste printing.