Microstrip Antenna Design for Wireless Applications

Praveen Kumar Malik, Sanjeevikumar Padmanaban, Jens Bo Holm-Nielsen, Praveen Kumar Malik, Sanjeevikumar Padmanaban, Jens Bo Holm-Nielsen

• Publisher: CRC Press
• Year: 2021
• Print ISBN: 9780367554385
• eBook ISBN: 9781000417968
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

This book focuses on recent advances in the field of microstrip antenna design and its applications in various fields including space communication, mobile communication, wireless communication, medical implants and wearable applications. Scholars as well as researchers and those in the electronics/ electrical/ instrumentation engineering fields will benefit from this book. The book shall provides the necessary literature and techniques using which to assist students and researchers would design antennas for the above- mentioned applications and will ultimately enable users to take measurements in different environments. It is intended to help scholars and researchers in their studies, by enhancing their the knowledge and skills in on the latest applications of microstrip antennas in the world of communications such as world like IoT, D2D, satellites and wearable devices, to name a few.

FEATURES

• Addresses the complete functional framework workflow in printed antenna design systems
• Explores the basic and high-level concepts, including advanced aspects in planer design issues, thus serving as a manual for those in the the industry while also assisting beginners
• Provides the latest techniques used for antennas in terms of structure, defected ground, MIMO and fractal designs
• Discusses case studies related to data-intensive technologies in microchip antennas in terms of the most recent applications and similar uses for the Internet of Things and device-to-device communication

Part IOverview and Introduction

1Microstrip Patch Antenna Techniques for Wireless Applications

Mahesh Kumar Aghwariya and Amit Kumar

DOI: 10.1201/9781003093558-2

1. 1.1Introduction of Antennas
2. 1.2Rectangular Microstrip Patch Antennas
3. 1.3Fringing Effect in Microstrip Antennas
4. 1.4Microstrip Antenna Feeding Techniques
5. 1.5Comparison of Microstrip Antennas with Conventional Antennas
6. 1.6Advantages and Disadvantages of Microstrip Patch Antennas
7. 1.7Application of Microstrip Antennas
8. 1.8Conclusion

1.1 Introduction of Antennas

An antenna is a device used for converting radio frequency (RF) signals propagating in a conductor into electromagnetic waves in free space or for converting guided electromagnetic waves into electrical signals. The antenna acts as a converter between freely propagating waves in space and electromagnetic waves. The name is taken from zoology, in which the Latin word antennae is used to describe the long, thin feelers owned by many insects. Antennas exhibit the property of reciprocity; this shows the identical property of the antenna while transmitting and receiving the signals [1]. Almost all widely used antennas are resonant devices, which are used at the narrowband of frequency [2]. All antennas perform two basic and complementary functions: firstly, they convert electromagnetic radiation into voltage and current; secondly, they convert the voltage and current into electromagnetic radiation that is transmitted into open space. The electromagnetic radiation that is transmitted into space consists of electric fields that are measured in V/M and magnetic fields that are measured in amp/m. According to the type of area to be detected, the antenna adopts a specific structure. The earliest existing antennas are not much different from RF generators in principle, such as the antenna used by Heinrich Hertz when he first proved the existence of electromagnetic waves in 1888. An antenna can be made from a parallel combination of inductors and capacitors. If the plates of the capacitor are opened and the inductor is reduced to the inductance of the coil, a dipole antenna will eventually be produced.

In fact, resonant circuits are still often used as a means to explain the various properties of antennas. It was not until about 1900, when a transmitting station and a receiving station were established, that a clear distinction was made and the antenna was classified as an independent component of the radio system. The microstrip antenna (MSA), also called the patch antenna, was a new design structure patented in 1955. It did not find many applications in the first couple of decades; however, for the last few years these have been widely used in wireless communication. In a microstrip antenna, dielectric material called substrate is sandwiched between two plates of the conducting materials [3]. The lower conducting surface and the upper conducting plate are called the ground plane and a patch, respectively. The patch and ground plane of the antenna are linked to the supply byline called the microstrip feed line. Many types of feeding methods are used to provide the supply to antenna. The microstrip antennas are also known as the printed antennas because of the similar fabrication process of printed circuit board (PCB). These are very small-sized planar antennas that are very useful in wireless communication. Installation of these antennas is very easy due to the fact that they are compact and lightweight. The size and shape of the patch are important aspects on which the performance of the microstrip antenna depends. Various shapes of the patch are being used to design the MSA. Some commonly used shapes are illustrated in Figure 1.1.

Figure 1.1Various shapes of radiating patches.

All these shapes can be used as patches in the MSA based on the operating frequency and required performance. The rectangular and circular patches are the extensively used shapes in the design of the microstrip patch antenna.

1.2 Rectangular Microstrip Patch Antennas

The Rectangular Microstrip Patch Antenna (RMSPA) is the most commonly used microstrip antenna. In the RMSPA, a conducting rectangular-shaped structure is used as a patch to design the antenna. The basic structure of the antenna is given in Figures 1.2 and 1.3.

Figure 1.2Microstrip patch antenna.

Figure 1.3Top view of the microstrip patch antenna.

Figure 1.1 represents the complete structure of an RMSPA, Figure 1.2 the top view of the RMSPA and Figure 1.3 the side view of the RMSPA.

In the given figures:

L = length of the microstrip patch

W = width of the microstrip patch

H = height of the substrate

The performance of the microstrip patch antenna depends on various parameters like length (L), width (W), substrate thickness (H) dielectric constant of the substrate material and also on the location of the feed line. In a properly designed RMSPA, the radiation intensity is normal to the radiating element [3, 4]. The antenna radiates from the width and not from the long side of the patch; hence, the radiation or radiation efficiency of the antenna is determined by the width of the patch (W). The smaller the value of W, the smaller the radiation, and the larger the value of W, the larger the radiation. The bandwidth of the antenna depends on W along with the substrate thickness H of the dielectric materials. The large value of W represents a larger bandwidth. The gain of the antenna is also determined by the W and it also depends on various other parameters. The large value of W represents the larger gain of the antenna. The resonating frequency of the antenna can be found by the length (L) of the patch. For the rectangular microstrip antenna, the typical value of L is one-third of one-half the wavelength depending upon the relative dielectric constant of the substrate material, which is commonly from 2.0 to 10.0. The lower values of the dielectric constants reflect higher efficiency. The operating frequency, also called the resonance frequency, of the antenna is based on the length (L) of the patch and effective dielectric constant of the substrate material as shown in Table 1.1.

The mathematical equation of the resonance frequency is given by the following equation:

f0=C2Lεeff(1.1)

Table 1.1 Commonly used substrate materials

Substrate	Dielectric constant (ϵr)	Loss tangent (tan )
Glass Epoxy	4.4	0.02
96% Alumina	9.4 (5%)	0.0010
99.5% Alumina	9.8 (5%)	0.0001
Sapphire	9.4, 1.6	0.0001
Unreinforced PTFE, Cuflon	2.1	0.0004
Reinforced PTFE, RT Duroid 5880	2.2 (1.5%)	0.0009
Foam	1.05	0.0001
Air	1	0

1.3 Fringing Effect in Microstrip Antennas

When we feed the patc...

Table of contents

• Cover
• Half-Title Page
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• Organization of the Book
• Editors
• Associate Editors
• Part I Overview and Introduction
• Part II Performance Analysis of Microstrip Antennas
• Part III Multiple-Input Multiple-Output (MIMO) Antenna Design and Its Applications
• Part IV Fractal and Defected Ground Structure Microstrip Antennas
• Part V Microstrip Antennas in Vehicular Communication
• Part VI Importance and Use of Microstrip Antennas in IoT
• Part VII Ultra-Wideband Antenna Design for Wearable Applications
• Part VIII Microstrip Antenna Design for Miscellaneous Applications
• Index