Innovative and Intelligent Technology-Based Services For Smart Environments - Smart Sensing and Artificial Intelligence

Proceedings of the 2nd International Conference on Smart Innovation, Ergonomics and Applied Human Factors (SEAHF'20), held online, 14-15 November 2020

Sami Ben Slama, Fethi Choubani, Cesar Benavente-Peces, Afef Abdelkarim, Sami Ben Slama, Fethi Choubani, Cesar Benavente-Peces, Afef Abdelkarim

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000401295
• Edition: 1
• Topic: Informatik
• Subtopic: Künstliche Intelligenz (KI) & Semantik

This book contains a collection of high-quality papers describing the results of relevant investigations and cutting-edge technologies, aimed at improving key aspects of real life, including major challenges such as the development of smart cities, smart buildings, smart grids, and the reduction of the impact of human activities on the environment. Sustainability requires the use of green technologies and techniques and good practices. Artificial intelligence seems to be an appropriate approach to optimize the use of resources. The main focus of this book is the dissemination of novel and innovative technologies, techniques and applications of artificial intelligence, computing and information and communications technologies, and new digital services such as digital marketing, smart tourism, smart agriculture, green and renewable energy sources. Besides, this book focuses on nurturing energy trends including renewable energies, smart grids, human activity impact, communication, behaviour, and social development, and quality of life improvement fields based on the innovative use of sensors, big data and the Internet of things (IoT), telecommunications and machine learning.

Section I: Telecommunications and computing technologies

Compact and multiband CPW printed monopole antenna based on CLL elements for wireless applications

M. Smari, S. Dakhli & F. Choubani

University of Carthage, SUPCOM, Ariana, Tunisia

J.M. Floc’h

IETR, INSA, Rennes, France

DOI 10.1201/9781003181545-1

ABSTRACT: The design and performance characteristics of single, dual and tri-band printed CPW monopole antenna covering UMTS (1.93–1.99 GHz), ISM (2.43–2.4835 GHz), WLAN 2.4 GHz, WiMAX 2.5 GHz and S-band 3 GHz frequencies band are reported. These antennas are based on a coaxially fed printed monopoles integrated in a planar configuration with capacitively loaded loops (CLLs) as its near-field resonant parasitic radiators (NFRP). In the proposed technology, the number of operating frequencies is determined by the number of CLLs. These antennas are geometrically simple and have a compact size. The simulated results of return loss, surface currents and radiation patterns are presented and discussed.

1 Introduction

The interest in and demand for wireless and mobile platforms has grown dramatically. Applications include, for example, biosensors, RFID tags, radars, health applications and crop monitoring and communication systems. Consequently, the need and desire for multifunctional and compact antennas [1–8] has also blossomed, and research in this area has flourished.

In this paper, we propose a multiband printed monopole antenna composed with a monopole antenna associated to Capacitively Loaded Loop (CLL). This study covers the monopole alone then adds CLLs to the basic structure in order to grant multi-frequency behavior. The proposed antenna is suitable for multi-standard wireless communication applications.

2 Proposed Antennas Design

2.1 Basic structure: Monopole alone

The design procedure starts with the basic structure (Figure 1). It consists on a monopole antenna of length 32.5 mm and width of 1.2 mm, printed on a 35×35 mm².

Figure 1. Antenna design (a) Schema of the structure under HFSS. (b) Geometry and dimensions (in mm).

The resulting antenna was fabricated with an FR4 substrate (dielectric constant ε_r = 4.6, tan δ = 0.02 and thickness h = 0.8 mm) and fed by a CPW transmission line with the input impedance of 50Ω. The monopole is designed to operate at 2.45GHz. The structure was simulated by using the ANSYS-HFSS high frequency structure simulator.

2.2 Monopole with one CLL element

A Capacitively Loaded Loop (CLL) is placed in the near field region of the printed monopole in order to generate an additional frequency lower than of the driven element. The printed monopole is designed to operate at F₁ = 2.45 GHz in the ISM band without any additional matching network. The CLL is designed with an optimized distance between the monopole arm and the ground strip to operate at F₂ = 0.9 GHz of GSM band.

Figure 2. Proposed antenna design with one CLL element: (a) Schema of the structure under HFSS (b) Geometry and dimensions (in millimeters) of the antenna.

2.3 Monopole with two CLL elements

Two Capacitively Loaded Loops (CLLs) are placed in the near field region of the printed monopole in order to generate an additional frequency lower than the driven element. In addition to the structure described in last section 2.2, a second CLL element (CLL2) is inserted at the left side of the monopole and designed to operate at F₃ = 2GHz of UMTS band.

Figure 3. Proposed antenna design with Two CLL elements (a) Schema of the structure under HFSS. (b) Geometry and dimensions (in mm) of the antenna.

3 Simulation Results

3.1 Single-band antenna

3.1.1 Return loss

The simulated return loss shows the resonance frequency of the monopole F₁=2.45GHz (Figure 4).

Figure 4. Simulated return loss |S₁₁| of the single-band antenna.

The operating frequency band simulated for the single-band antenna is 2.2–2.7GHz, which can apply to WLAN 2.4GHz and WIMAX 2.5 GHz.

3.1.2 Radiation patterns

The simulated 3D-radiation pattern of the monopole antenna at the resonance frequency F1 is given in Figure 5.

Figure 5. Simulated 3D-radiation pattern of the proposed antenna at the resonance frequency F₁ = 2.45 GHz.

3.2 Dual-band antenna

3.2.1 Return loss

The simulated return loss of the antenna with the insertion of one CLL is presented in Figure 6.

Figure 6. Simulated return loss |S₁₁| of the dual-band antenna.

We can conclude from Figure 6 that a second resonance frequency F₂ =1.33GHz is generated in addition to the first resonant frequency F₁=2.45GHz of the reference antenna when we insert a CLL. According to presented results, two observations can be made:

• The operating frequency F₁ of the basic antenna is slightly shifted from 2.45 to 2.99GHz and remains unchanged. This shift of frequency can be explained by the coupling effect between the monopole and CLL element.
• The additional frequency F₂ is shifted to a lower frequency.

In the dual-band mode, the simulated frequency bands are 1.28–1.37GHz/2.7–3.2GHz.

3.2.2 Radiation patterns

The simulated 3D-radiation patterns of the structure are given in Figure 7. These patterns correspond to the resonant frequencies F₁ and F₂.

Figure 7. Simulated 3D-radiation pattern of the proposed antenna (a) at F₁=2.99 GHz; (b) at F₂=1.33 GHz.

We can notice from Figure 7 that the antenna presents two radiation behaviors. At the frequency F₁ (Figure 7.a), the structure is characterized by an axially symmetric radiation pattern around the y-axis. At this frequency, the radiation patterns correspond to the basic printed monopole.

Whereas, and according to Figure 7.b, the str...