Design and Analysis of Ultra Wide Band MIMO Antennas for Wireless Communication THESIS

133 Pages·2012·6.59 MB·English

Design and Analysis of Ultra Wide Band MIMO Antennas for
Wireless Communication

THESIS
Submitted in Partial Fulfillment of the Requirement for
The Award of the Degree of
DOCTOR OF PHILOSOPHY
IN
Electronic and Communication Engineering
BY
GARIMA SRIVASTAVA
(ID. No: 11PHEC102)

DEPARTMENT OF ELECTRONIC AND COMM. ENGINEERING
FACULTY OF ENGINEERING AND TECHNOLOGY
SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE, TECHNOLOGY AND
SCIENCES
Deemed-To-Be-University
(FORMERLY ALLAHABAD AGRICULTURAL INSTITUTE)
NAINI, ALLAHABAD-211007
INDIA
2016

DECLARATION
I, Garima Srivastava declares that the work presented in this dissertation entitled ‘Design
and Analysis of Ultra Wide Band MIMO Antennas for Wireless Communication’
submitted to the Department of Electronics and Communication Engineering, in the Faculty
of Engineering and Technology Sam Higginbottom Institute of Agriculture, Technology
and Sciences, Deemed University, Naini, Allahabad, for the award of the Doctor of
Philosophy degree in Electronics and Communication Engineering is an original work. I
have neither plagiarized nor submitted the same work for the award of any other degree. In
case this undertaking is found incorrect, my degree may be withdrawn unconditionally by
the University.

Date: Signature of Student

Place: Allahabad Garima Srivastava

(ID. No: 11 PHEC 102)
CERTIFICATE
Certified that the dissertation entitled ‘Design and Analysis of Ultra Wide Band MIMO
Antennas for Wireless Communications’ submitted to Sam Higginbottom Institute of
Agriculture, Technology and Sciences, Deemed University, Naini, Allahabad in partial
fulfillment of the requirement for the degree of Doctor of Philosophy in Electronics and
Communication Engineering in Faculty of Engineering and Technology is a bonafide
record of dissertation report carried out by Ms. Garima Srivastava (ID.No:11 PHEC 102)
under my supervision and guidance.

(Signature)
Dr Rajeev Paulus.
(Supervisor)
Department of Electronics and Communication Engineering,
SHIAT, Naini, Allahabad

Place: Allahabad
Date:
CERTIFICATE
Certified that the dissertation entitled ‘Design and Analysis of Ultra Wide Band MIMO
Antennas for Wireless Communication’’ submitted to Sam Higginbottom Institute of
Agriculture, Technology and Sciences, Deemed University, Naini, Allahabad in partial
fulfillment of the requirement for the degree of Doctor of Philosophy in Electronics and
Communication Engineering Faculty of Engineering and Technology is a bonafide
record of dissertation report carried out by Ms. Garima Srivastava (ID.No:11 PHEC 102)
under my supervision and guidance.

(Signature)
Dr Binod Kumar Kanaujia.
Co-Supervisor,
Professor,
Department of Electronics and Communication Engineering,
Ambedkar Institute of Advanced Communication Technologies & Research,
Delhi
ABSTRACT
Ultra Wide Band (UWB) technology is rapidly developing area in the field of Wireless
Communication. There are many challenges in this field, one of the challenge is to design
an antenna which covers the entire UWB frequency range, the another challenge is to
design an UWB Multiple input-Multiple output antenna which will increase the channel
capacity and will allow several users to access the various services at the same time. The
objective of this thesis is to design UWB antennas that operates in the frequency range
from 3.1 to 10.6 GHz and has band notched characteristics. Another objective is to design
UWB MIMO antenna and UWB MIMO antennas with band notched characteristics.
The thesis starts with designing and implementing UWB antennas with discussions
covering their operation, electrical behavior and performance. UWB antennas are designed
and analyzed using microstrip feeding technique and coaxial feed to achieve low profile
and compatibility with Printed Circuit Board. Also, Different techniques for obtaining a
bandstop function in the 5 to 6 GHz frequency band to avoid interference with other
existing worldwide interportability for microwave access (WIMAX) systems are
numerically and experimentally presented.
In Communication systems, Multiple Input–Multiple Output (MIMO) technology, which
involves the use of multiple antennas at both the transmitter and receiver, is used to
significantly enhance the data transmission performance and channel capacity. Antennas
for this system are designed, to ensure that isolation between elements should be less than -
15 dB. Thus, Antennas are typically placed apart from others at least half wavelength of
the lowest operating frequency, and this could lead to increase in dimensions of MIMO
antenna. Therefore, miniaturizing the antenna size and improving the isolation coefficients
are the two most important aims for MIMO antennas. An Ultra Wide Band (UWB) multiple
Page i
input and multiple output (MIMO) antenna having shared radiator with dual band rejection
characteristics is designed and analyzed. The proposed antenna is based on the concept of
dual polarization. The antenna consists of two tapered Co-planer Waveguide (CPW) feeds
printed on one side of the substrate and a circular shared radiator on the other side. The
radiator is shared between two antenna elements. High isolation between the antenna
elements is achieved by introducing a rectangular slot in the circular radiator and an
inverted Y shaped stub on the ground plane at an angle of 45°. The designed antenna rejects
the WiMAX and WLAN band of frequencies by employing Elliptical Split Ring Slots
(ESRS) in the shared radiator. The diversity performance of UWB MIMO antenna is also
studied. The antenna is fabricated on FR4 substrate and has a small size of 41 mm × 41
mm. The simulated and measured results are in good agreement which demonstrate its
potential use in UWB portable devices. The challenge of multipath fading in Ultra Wide
Band technology is removed with another MIMO antenna in the thesis. The high isolation
among the antenna elements is a basic requirement for good diversity performance. To cope
up with this challenge a uniplanar UWB MIMO antenna is designed and analyzed. This
antenna can also be used for Wireless Personal Area Network (WPAN), Wireless Body
Area Network (WBAN). It has single common circular radiator for both the antenna
elements.

Keywords: Band-notched ultra-wideband (UWB) antenna, MIMO antenna, High isolation,
notched characteristics.

Page ii
ACKNOWLEDGEMENT
I have no words to express my deep sense of gratitude to my supervisor Dr Rajeev Paulus,
Assistant Professor, Department of Electronics and Communication Engineering, Sam
Higginbottom Institute of Agriculture, Technology and Sciences, Deemed University,
Naini, Allahabad, for his consistent help in the form of discussions, guidance and
suggestions to improve upon our research findings. I sincerely thank him for all his kind
support that was essential to complete the work in the present form. Professor B.K.
Kanaujia, Department of Electronics and Communication Engineering, Ambedkar Institute
of Advanced Communication Technologies & Research, my external supervisor has always
been a great source of inspiration to me. I obtained many fruitful ideas from him which
helped me to a great extent during the course of this work. I express my kind thanks to him.
I respectfully thank Professor A.K. Jaiswal, HoD, Department of Electronics and
Communication Engineering, Sam Higginbottom Institute of Agriculture, Technology and
Sciences, Deemed University, Allahabad for his kind support and encouragements, which I
received from him during this period. I profusely thank Professor Ajit Paul, HoD,
Department of Mathematics, Sam Higginbottom Institute of Agriculture, Technology and
Sciences, Deemed University, Allahabad and my SAP committee member for his timely
encouragements & kindhearted generous support extended to me. Also, I am short of words
to express my deep gratitude & thanks to Dr Akhilesh Mohan, Assistant Professor,
Department of Electronics & Electrical Communication Engineering, Indian Institute of
Technology (IIT), Kharagpur, for his innovative ideas and consistent help in completing
this work.
Name of the Student:
Signature of Student:
Page iii
TABLE OF CONTENTS
Title Page No
TITLE PAGE
UNDERTAKING
CERTIFICATE OF ORIGINAL WORK
STUDENT ADVISORY COMMITTEE CERTIFCATE
EVALUATION COMMITTEE REPORT
ABSTRACT i
ACKNOWLEDGEMENT iii
TABLE OF CONTENTS v
LIST OF FIGURES vii
LIST OF TABLES x
LIST OF ABBREVIATIONS xi
LIST OF NOTATIONS xiii

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TABLE OF CONTENTS
CHAPTER I- INTRODUCTION
1.1 Motivation and challenges of UWB antenna Design 1
1.2 Introduction to ultra-wide band technologies 2
1.2.1 Characteristics of Ultra wide band 6
1.2.2 Working of Ultra wide band 7
1.3 Multiple antenna Techniques 9
1.3.1 Spatial Diversity: 9
1.3.2 Spatial Multiplexing 11
1.3.3 Adaptive Antenna System 11
1.4 Multiple input Multiple output technology 14
1.4.1 Basic Building Block of MIMO 15

1.5 Ultra-wideband MIMO Antennas 16
1.5.1 Design Challenges in UWB MIMO antenna systems 16
1.5.2 Isolation and Bandwidth Enhancement 17
1.6 Objective 18
1.7 Organization of thesis 18

CHAPTER II LITERATURE REVIEW 20-46
CHAPTER III MATERIALS AND METHODS
3.1 Numerical/Analytical Techniques 47
3.2 Fundamental antenna parameters 49
3.3 Model Analysis of Microstrip Antenna 55
3.4 Ultra-wide band antenna design methodology 56
3.4.1 A Hot Air Balloon shaped Microstrip fed UWB Antenna 61
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