Switch Parasitic Array Antenna For 5g Communication: Comsats University Islamabad Abbottabad Campus-pakistan

SWITCH PARASITIC ARRAY ANTENNA FOR 5G COMMUNICATION

By

Jam Talha Abbas CUI/FA13-BCE-044/ATD Hajra Khan CUI/SP15-BCE-023/ATD

BS Thesis In

BS Electrical (Computer) Engineering

COMSATS University Islamabad Abbottabad Campus-Pakistan Spring, 2019

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COMSATS University Islamabad-Abbottabad Campus

Switch Parasitic Array Antenna for 5G Communication A Thesis Presented to

COMSATS University Islamabad- Abbottabad Campus In partial fulfillment Of the requirement for the degree of

BS Electrical (Computer) Engineering By

Jam Talha Abbas CUI/FA13-BCE-044/ATD Hajra Khan CUI/SP15-BCE-023/ATD

Spring, 2019

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Switch Parasitic Array Antenna for 5G Communication

An Under Graduate Thesis submitted to Department of Electrical and Computer Engineering as partial fulfillment of the requirement for the award of Degree of Bachelor of Science in Electrical (Computer) Engineering.

Name

Registration Number

Jam Talha Abbas

CUI/FA13-BCE-044/ATD

Hajra Khan

CUI/ SP15-BCE-023/ATD

Supervisor Dr. Imdad Khan Associate Professor, Electrical and Computer Engineering Abbottabad Campus COMSATS University Islamabad (CUI) Abbottabad Campus July, 2019

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Final Approval This thesis titled

Switch Parasitic Array Antenna for 5G Communication By

Jam Talha Abbas CUI/FA13-BCE-044/ATD Hajra Khan CUI/SP15-BCE-023/ATD

Has been approved For the COMSATS University Islamabad, Abbottabad Campus Supervisor: ______________________________________________ Dr. Imdad Khan, Associate Professor Department of Electrical and Computer Engineering/Abbottabad Campus

HOD: ______________________________________________ Dr. Imdad Khan, Associate Professor Department of Electrical and Computer Engineering/Abbottabad Campus

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Declaration We, Jam Talha Abbas (CUI/FA13-BCE-044/ATD) and Hajra Khan (CUI/SP15BCE-023/ATD) hereby declare that we have produced the work presented in this thesis, during the scheduled period of the study. We also declare that we have not taken any material from any source except referred to wherever due that amount of plagiarism is within acceptable range. If a violation of HEC rules occurred in this thesis, we shall be liable to punishable action under plagiarism rules of the HEC.

Date: _________________

Signature of the Students:

____________________ Jam Talha Abbas CUI/FA13-BCE-044/ATD

____________________ Hajra Khan CUI/SP15-BCE-023/ATD

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Certificate This is to certify that the thesis entitled “Switch Parasitic Array Antenna for 5G Communication” submitted by Jam Talha Abbas and Hajra Khan is an authentic work carried out by them successful under my supervision. To the best of my knowledge the matter embodied in the thesis has not been submitted to any other university/ institute for the award of any degree or diploma

Date: _________________ Supervisor:

_________________________ Dr.Imdad Khan Associate Professor

Head of Department:

_____________________________ Dr. Imdad Khan Associate Professor Department of Electrical and Computer Engineering

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DEDICATION Starting with the name of ALLAH ALL MIGHTY, against WHOSE WILL we are nothing but dust. We dedicate this thesis to our Parents who have never failed to give us financial and moral support as well as fulfilling all our needs during the time we developed this system and throughout the course of our educational career. Their evergreen love and encouragement never let us down, and empowered us to purpose beyond our imaginations. To our supervisor ‘Dr. Imdad Khan’ for humbly accepting our proposal, for his support, teachings and his enlightening ideas, which kept us working day and night with devotion to reach our goal. To our friends for their incessant support, and their streaming philosophies no matter how absurd they were, that helped us in understanding most of the things which alone or small group cannot achieve. We are also thankful to various colleagues, teachers and other lab staff who supported, advised and assisted our project.

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ACKNOWLEGDGEMENTS All praises to ALLAH, the source of knowledge, wisdom within and beyond comprehension who enable us to accomplish our goal. The completion and production of every book and project is not a single man’s task. One should definitely take the assistance and cooperation of some people. We have also completed our work on the same format. Many people have extended their valuable assistance, which enable us to give final shape of this manuscript. We express our heartfelt gratitude to our parent and family for their prayer, moral support and sincere wishes for the completion of our work. We want to thank our thesis project supervisor Dr. Imdad Khan for their continuing interest and support of our work. Their generosity to share his ideas with us was the starting point for the work of this thesis. We would like to offer thanks to our friends for their help and valuable suggestions.

Jam Talha Abbas (CUI/FA13-BCE-044/ATD) Hajra Khan (CUI/SP15-BCE-023/ATD)

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ABSTRACT Switch Parasitic Array Antenna for 5G Communication This is an Era of wireless communication so to achieve effective and affordable communication in wireless technology compact and effective results in 5G communication. One of the best radiator is Monopole. Monopoles being made up of straight rod-shaped conductor, often mounted perpendicularly over some type of conductor surface called a ground plane So in this project we will use twelve monopoles as a parasitic elements and one monopole as a driven element. We will achieve higher directivity and it is capable of 360 degree steering. We will achieve our results by making some of the elements short and some of the elements open.

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TABLE OF CONTENTS Introduction ....................................................................................................... 1 1.1 Wireless Communication ................................................................... 2 1.2 Research Gaps .................................................................................... 2 1.3 Problem Statement ............................................................................. 2 1.4 Main Objectives ................................................................................. 2 1.5 Background Knowledge ..................................................................... 2 1.6 Work Covered in Thesis ..................................................................... 3 1.7 Summary ............................................................................................ 3 Literature Review .............................................................................................. 4 2.1 Antenna .............................................................................................. 5 2.2 Antenna Parameters ............................................................................ 5 2.2.1 Bandwidth ............................................................................ 5 2.2.2 Directivity............................................................................. 5 2.2.3 Gain ...................................................................................... 7 2.2.4 Radiation Pattern .................................................................. 7 2.2.5 Efficiency ............................................................................. 8 2.2.6 Return Loss .......................................................................... 8 2.2.7 Voltage Standing Wave Ratio .............................................. 9 Monopole Antenna .......................................................................................... 10 3.1 Introduction to the Monopole ........................................................... 11

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3.2 Basic Characteristics ........................................................................ 11 3.3 Advantages of Monopole ................................................................. 12 3.4 Basic Shapes of Monopole ............................................................... 12 3.4.1 Crescent-shaped monopole ................................................ 13 3.4.2 Feed Spanner Monopole .................................................... 13 3.4.3 Monopole ........................................................................... 13 Feeding Methods .............................................................................................. 15 4.1 Micro-strip Transmission Line Technique ....................................... 16 4.2 Co-axial probe Feeding Technique .................................................. 16 4.3 Slot Aperture .................................................................................... 17 4.4 Co-Planar Waveguide Feed ................................................... 18 Parameters ....................................................................................................... 20 5.1 Monopole Parameters ....................................................................... 21 5.1.1 Monopole Length ............................................................... 21 5.1.2 Monopole Radius ............................................................... 21 5.1.3 Ground Radius.................................................................... 21 5.1.4 Ground Thickness .............................................................. 21 5.1.5 Frequency ........................................................................... 21 5.2 DESIGN PARAMTER ......................................................... 22 Results and Future Work ............................................................................... 23 6.1 Results of Switching Elements ......................................................... 24 6.1.1 Result 1 ............................................................................... 24

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6.1.2 Result 2 ............................................................................... 25 6.1.3 Result3 ................................................................................ 26 6.1.4 Result4 ................................................................................ 27 6.1.5 Result5 ................................................................................. 28 6.1.6 Result6 ................................................................................ 29 6.1.7 Result7 ................................................................................ 31 6.1.8 Result8 ................................................................................ 32 6.1.9 Result9 ................................................................................ 33 6.1.10 Result10 ............................................................................ 34 6.1.11 Result11 ............................................................................ 35 6.3 Conclusion .............................................................................. 36 6.4 Future Work ............................................................................ 36 References ........................................................................................................ 38

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LISTOF FIGURES

Figure 2.1 Antenna Working…………………………………………………………..5 Figure 3.1 Crescent Shaped Monopole…………………………………...………….13 Figure 3.2 Feed Spanner Monopole ………………………………………………….13 ………………………………………………14

Figure 3.3 Monopole

Figure 4.1 Micro-strip Transmission Line Technique………………………...……....16 Figure 4.2 Slot Aperture Technique…………………………………………………..17 Figure 4.3 Co-axial Probe Feeding Technique….……………………………………18 Figure 4.4 Co-planar Waveguide Feed…….…………....……………….……………18 …………………………………………….244

Figure 6.1 Result 1 Figure 6.2 Radiation Pattern 1

…………………………………………….255

Figure 6.3 Result 2 Figure 6.4 Radiation Pattern 2

Figure 6.6 Radiation Pattern 3

………………………………………………...27 …………………………………………….27

Figure 6.7 Result 4 Figure 6.8 Radiation Pattern 4

…………………………………………………28

………………………………………………………………28

Figure 6.10 Radiation Pattern 5 Figure 6.11 Result 6

………………………………….……………...266 ………………………………………….....26

Figure 6.5 Result 3

Figure 6.9 Result 5

………………………………….……………...255

……………………………………………29 ………………………………………….……..29

Figure 6.12 Radiation Pattern 6 ……………………………………………………...30 xiii

……………………………………..…….31

Figure 6.13 Result 7 Figure 6.14 Radiation Pattern 7 Figure 6.15 Result 8

…………………………………………..……31

…………………...……………………………………..….32

Figure 6.16 Radiation Pattern 8

… …...……………………………………..….33

Figure 6.17 Result 9 ………… ………...……………………………………..….33 Figure 6.18 Radiation Pattern 9… ……...……………………………………..….34 Figure 6.19 Result 10

………………...……………………………………..….34

Figure 6.20 Radiation Pattern 10…… …...……………………………………..….35 Figure 6.21 Result 11 …………………...……………………………………..….35 Figure 6.22 Radiation Pattern 11…… …...……………………………………..….36

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LIST OF TABLES

TABLE 1 DESIGN PARAMETER…………………………………………………22

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ABBREVIATIONS

MR

Monopole Radius

ML

Monopole Length

GR

Ground Radius

GT

Ground Thickness

F

Frequency

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Chapter 1 Introduction

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1.1 Wireless Communication Wireless communication is a term that describes the communication between two devices using a radio signal instead of a wired connection[1]. For this the entire world is using efficient radio signal receivers and transmitters. Monopole is one of the kind.it being an effective radiator also supports many features including ease of fabrication, high directivity and gives flexibility in design and to analyses the results in order to achieve required resonant frequencies depending upon our coverage requirements. Monopoles have high radiation efficiency, bandwidth and gain enhancement which makes them prior to the dipole. Monopole is in rod- shaped. The Monopoles have properties such as very less phase noise, small size, stability in frequency and temperature, ease of integration with existing technologies and other hybrid MIC circuitries, flexible construction and the ability to withstand harsh environments. Monopoles are very promising for applications in wireless communication. 1.2 Research Gaps In this project we will try to fill the gap of achieving high directivity using monopoles is resonating on at particular frequency. 1.3 Problem Statement Switch Parasitic Array Antenna for 5G Communication. 1.4 Main Objectives The main objective of this thesis is to cover the basics of antennas, their different parameters like Gain, Radiation pattern, bandwidth, directivity, efficiency, polarization etc. Further moving towards Monopole antennas how we obtain beam in a specific direction by making some of the elements short and some of the elements open[1]. 1.5 Background Knowledge The area under the consideration is wireless communication in which the study on Monopole antenna is being carried out. Monopoles being effective radiators are well known in the world of wireless communication.

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1.6 Work Covered in Thesis This thesis covers the switching of parasitic elements by making some of the elements open and short. 1.7 Summary This entire work comes under the umbrella of wireless communication in which antennas play a vital role. Monopoles are under consideration in the present era due to their unique properties. Here the switching parasitic elements by making some of elements open and short[1]. We are using twelve parasitic elements and one driven element. By switching the parasitic elements we are capable of 360 degree beam steering and achieving higher bandwidth.

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Chapter 2 Literature Review

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2.1 Antenna

Figure 2.1 Antenna Working

An antenna is basically a device which can radiate or receive radio signals. It can be a receiving or transmitting antenna. The receiving antenna catches radio waves and convert them into electrical signals which are then fed to different connected devices. The Figure 2.1 shows transmitting antenna which on the other hand works opposite it converts electrical signals into radio waves which can move long distances in a or random direction. The radio waves are electromagnetic radiations in which electric field and magnetic field are produced that propagate in a particular direction. 2.2 Antenna Parameters Antenna parameters are defined as the properties of an antenna. Which are explained below

2.2.1 Bandwidth Bandwidth is defined as the range of frequencies over which the antenna satisfies conditions. The bandwidth can be considered to be a range of frequency on either side of center frequency where the antenna characteristics are within acceptable value of those at center frequency. For broad band antenna the bandwidth is usually expressed as the ratio of upper to lower frequency of acceptable operation. Because the characteristics of an antenna do not necessarily vary in the same manner or are even critically affected by the frequency there is no unique characterization of the bandwidth

2.2.2 Directivity It is defined as how much directive the antenna radiation pattern is. Basically, the term directivity in the new 1983 version has been used to replace the term directive gain of 5

the old 1973 version. In the 1983 version the term directive gain has been deprecated. According to authors of the new standard this change brings this standard in line with common usage among antenna engineers and with other international standard notably those of the international electrochemical commission (IEC) therefore directivity of an antenna defined as the ratio of radiation intensity in given direction from the antenna to the radiation intensity averaged over all directions. The average radiation intensity is equal to the total power radiated by the antenna divided by 4. If direction is not specified the direction of maximum radiation intensity is implied. Stated more simply the directivity of non-isotropic source is equal to the ratio of it radiation intensity in given direction over that of isotropic source [3]. In mathematical form it can be written as Prad. 𝑈

4𝜋𝑈

𝐷=𝑈 =𝑃 0

(2.1)

𝑟𝑎𝑑

𝑈

𝐷𝑚𝑎𝑥 = 𝐷𝑜 = 𝑈𝑚𝑎𝑥 = 𝑂

4𝜋𝑈𝑚𝑎𝑥 𝑃𝑟𝑎𝑑

(2.2)

D= Directivity Do = Maximum Directivity U = Radiation Intensity (W/unit solid angle)

𝑈𝑚𝑎𝑥 = Maximum radiation intensity (W/unit solid angle) 𝑈𝑂 = Radiation intensity of isotropic (W/ unit solid angle) 𝑃𝑟𝑎𝑑 = Total radiated power (W) 𝐷𝑜 = Maximum Directivity Dθ = (𝑃 D∅ =

4𝜋𝑈𝑂 𝑟𝑎𝑑 )𝜃 +(𝑃𝑟𝑎𝑑 )∅

4𝜋𝑈𝑂 (𝑃𝑟𝑎𝑑 ) +(𝑃𝑟𝑎𝑑 ) 𝜃

(2.4) ∅

𝑈𝜃 = Radiation intensity in given direction contained in field component 𝑈∅ = Radiation intensity in given direction contained in field component 6

(2.3)

(𝑃𝑟𝑎𝑑 )𝜃 = Radiation power in all direction contained in field component (𝑃𝑟𝑎𝑑 )∅ = Radiation power in all direction contained in field component

2.2.3 Gain Gain is defined as how much received power antenna radiates in a particular direction. Although the gain of antenna is closely related to the directivity, remember that directivity is measure that describes only the directional properties of the antenna, and it is therefore controlled only by pattern. Absolute gain of an antenna is defined as the ratio of intensity, in a given direction to the radiation intensity that would be obtained if power accepted by antenna were radiated isotropically[2] The radiation intensity corresponding to isotropically radiated power is equal to the power accepted by the antenna divided by 4. In equation form this can be expressed as 𝑅𝑎𝑑𝑖𝑎𝑡𝑖𝑜𝑛 𝐼𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦

Gain = 4𝜋 𝑇𝑜𝑡𝑎𝑙 𝑖𝑛𝑝𝑢𝑡 𝑎𝑐𝑐𝑒𝑝𝑡𝑒𝑑 𝑝𝑜𝑒𝑟 = 4𝜋

𝑈(𝜃,∅) 𝑃𝑖𝑛

(2.5)

In most cases we deal with relative gain, which defined as the ratio of power gain in a given direction to the power gain of reference antenna in its reference direction. The power input must be same for both antennas the reference antenna usually a dipole horn or any other antenna whose gain can be calculated or it is known. In most cases however the reference antenna is lossless isotropic source. Thus G=

4𝜋𝑈(𝜃,∅)

𝑃𝑖𝑛 (𝑙𝑜𝑠𝑠𝑙𝑒𝑠 𝑖𝑠𝑜𝑡𝑟𝑜𝑝𝑖𝑐 𝑠𝑜𝑢𝑟𝑐𝑒)

(2.6)

When the direction is not stated the power gain is usually taken in direction of maximum radiation

2.2.4 Radiation Pattern The radiation pattern of an antenna is a plot of the relative field strength of the radio waves emitted by the antenna at different angles. It is typically represented by a three dimensional graph, or polar plots of the horizontal and vertical cross sections. It is a plot of field strength in V/m versus the angle in degrees.

7

2.2.5 Efficiency The total antenna efficiency eo is used to take into account losses at the input terminals and within the structure of the antenna [3]. Such losses may be due, to two factors given below 1. Reflection because of the mismatch between the transmission line and the antenna 2. I2R losses (conduction and dielectric) In general the overall efficiency can be written as

eo = er ec ed

(2.7)

Where,

eo = total efficiency er

= reflection efficiency

ec = conduction efficiency ed = dielectric efficiency 2.2.6 Return Loss The definition of return loss is that it is the loss of power in the signal returned / reflected by a discontinuity in a transmission line or optical fibre. This is normally expressed in decibels. In other words if all the power was transferred to the load, then there would be an infinite return loss. Conversely if there is an open or short circuit termination, then all the power will be returned and there will be no return loss. The return loss is normally calculated as follows: R = 10 log10 (PiPr) Where Pi = incident power

8

(2.8)

Pr = reflected power Then as the reflection coefficient Γ is the ratio of the forward and reflected voltages, and power is proportional R = 20 log 10 Γ)

(2.9)

Return loss is a figure which is widely used for assessing items like the input characteristics of an RF component, or when measuring the characteristics of a network using a vector network analyzer. As such the return loss is an important characteristic.

2.2.7 Voltage Standing Wave Ratio The standing wave ratio (SWR), also known as the voltage standing wave ratio (VSWR), is not strictly an antenna characteristic, but is used to describe the performance of an antenna when attached to a transmission line. It is a measure of how well the antenna terminal impedance is matched to the characteristic impedance of the transmission line. Specifically, the VSWR is the ratio of the maximum to the minimum RF voltage along the transmission line. The maxima and minima along the lines are caused by partial reinforcement and cancellation of a forward moving RF signal on the transmission line and its reflection from the antenna terminals. If the antenna terminal impedance exhibits no reactive (imaginary) part and the resistive (real) part is equal to the characteristic impedance of the transmission line, then the antenna and transmission line perfectly obeys impedance matching condition. VSWR =

𝑉𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑉𝑚𝑖𝑛𝑖𝑚𝑢𝑚

Where,

𝑉𝑚𝑎𝑥𝑖𝑚𝑢𝑚 = maximum amplitude of RF voltage 𝑉𝑚𝑎𝑥𝑖𝑚𝑢𝑚 = minimum amplitude of RF voltage

9

(2.10)

Chapter 3 Monopole Antenna

10

3.1 Introduction to the Monopole A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane. The driving signal from the transmitter is applied, or for receiving antennas the output signal to the receiver is taken, between the lower end of the monopole and the ground plane. One side of the antenna feedline is attached to the lower end of the monopole, and the other side is attached to the ground plane, which is often the Earth. This contrasts with a dipole antenna which consists of two identical rod conductors, with the signal from the transmitter applied between the two halves of the antenna 3.2 Basic Characteristics The basic features of Monopole are mentioned below: 

The load impedance of the quarter-wave monopole is half that of the dipole antenna or 37.5+j21.25 ohms.



There is no inherent conductor loss in dielectric resonators. This leads to high radiation efficiency of the antenna. This feature is especially attractive for millimeter (mm)-wave antennas, where the loss in metal fabricated antennas can be high.



Monopoles offer simple coupling schemes to nearly all transmission lines used at microwave and mm-wave frequencies. This makes them suitable for integration into different planar technologies. The coupling between a Monopole and the planar transmission line can be easily controlled by varying the position of the Monopole with respect to the line.[4] The performance of Monopole can therefore be easily optimized experimentally.



The operating bandwidth of a Monopole can be varied over a wide range by suitably choosing resonator parameters.



Use of multiple modes radiating identically has also been successfully addressed.

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3.3 Advantages of Monopole 

As the monopole antenna gets longer and the ground losses are reduced, the efficiency of the antenna gets better.



Higher efficiency.



As the monopole antenna gets longer and the ground losses are reduced, the efficiency of the antenna gets better. Vertical monopole antennas can achieve efficiencies of up to 80%.



A vertical monopole antenna can be used for any frequency shorter than two thirds of the wavelength.



Light weight, low volume, and low profile configuration, which can be made conformal



Monopole has high degree of flexibility and versatility, allowing for designs to suit a wide range of physical or electrical requirements of varied communication applications.



Easy of fabrication



High radiation efficiency



High dielectric strength and higher power handling capacity



Low production cost



Monopole antennas are easy to build and install. Passive monopoles are cheap to make and rugged.

3.4 Basic Shapes of Monopole The basic shapes of the Monopole are

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3.4.1 Crescent-shaped monopole

Figure 3.1 Crescent-shaped monopole

A planar multiband monopole antenna is presented for mobile wireless applications. The antenna is constructed from a crescent-shaped radiator patch, microstrip feed line, and defected ground structure (DGS). Theoretical and experimental characteristics are presented for this antenna, which achieves an impedance bandwidth of 58.3% (over 1.7-3.1 GHz), at a reflection coefficient |S11| < -10 dB and has an average gain of 1.75 dBi.

3.4.2 Feed Spanner Monopole

Figure 3.2 Feed spanner Monopole

3.4.3 Monopole Hemispherical shape DRA offers an advantage over the rectangular and cylindrical shapes as the interface between the dielectric and air is simpler [5]. By that, a closed form expression cab obtained for the Greens function. 13

Figure 3.3 Monopole

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Chapter 4 Feeding Methods

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There are several techniques to feed waveguide some of them are include in the following topics. 4.1 Micro-strip Transmission Line Technique In this method the Monopole is feed by printed transmission line. As shown in figure 4.1. Conventionally DR is directly placed on the transmission line that is on printed the Monopole A common method for coupling to dielectric resonators in microwave circuits is by proximity coupling to micro-strip lines. Micro-strip coupling will excite the magnetic fields in the Monopole to create the short horizontal magnetic dipole mode. The level of coupling can be changed by the lateral location of the Monopole with respect to the micro-strip line and on the relative permittivity of the Monopole. Micro-strip lines can be used as a series feed for a linear array of Monopole. This is an easy feeding technique, since it offers ease of fabrication and simplicity in modeling along with impedance matching . However, as the thickness of the dielectric substrate being used, rises, surface waves and spurious feed radiation also rises, which hampers the bandwidth of the antenna.

Figure 4.1 Micro-strip Transmission Line Technique

4.2 Co-axial probe Feeding Technique In this technique, the monopole is directly placed on the ground plane and excited by a coaxial feed through the substrate. It is shown in figure 4.2. It provides high coupling to DR which give high radiation efficiency. In this method, the probe can either be placed adjacent to the monopole or can be embedded within it .[5] The amount of coupling can be enhanced by adjusting the probe height and the monopole location. In 16

monopole, various modes can be excited depending on the location of the probe. For the probe located adjacent to the monopole, the magnetic fields of the TE11δ mode of the rectangular monopole are excited and radiate like a horizontal magnetic dipole. For a probe located in the center of a cylindrical monopole, the TE011 mode is excited and radiating like a vertical dipole. Another benefit of using probe coupling is that one can couple directly into a 50Ω system, without the requirement for a matching network. The drawback of this technique is hole needs to be drilled in monopole. The dimensions of the probe (length and radius) need to match the drilled hole otherwise it can affective dielectric constant will be affected; this cause a shift in resonance frequency of the antenna. [4.2]

Figure 4.2 Co-axial Probe Feeding Technique

4.3 Slot Aperture The most popular feeding technique for monopole is via the slot in the ground plane. The excitation method is known as Aperture coupling.it is applicable to monopole of any shapes such as cylindrical. The aperture works like a magnetic current running parallel to the size of the slot, which excites the magnetic fields inside the monopole. The aperture type of feeding consists of a slot cut in a ground plane and fed by a microstrip line below the ground plane. For avoiding spurious radiation, feed network is located below the ground plane. Moreover, slot coupling is an attractive technique for integrating monopole with printed feed structures. The coupling level can be changed by moving the monopole with respect to the slot. Generally, a high dielectric material is used for the substrate and a thick, low dielectric constant material is used for the top dielectric resonator patch to optimize radiation from the antenna. The main drawback of this feed technique is that it is problematic to fabricate due to multiple layers, which 17

also increases the antenna thickness. This feeding method also provides narrow bandwidth (up to 21%). The main advantage of this method that it avoids direct electromagnetic interaction between the feed line and the monopole. It is shown in the figure 4.3

Figure 4.3 Slot Aperture Technique

4.4 Co-Planar Waveguide Feed

Figure 4.4 Co-planar Waveguide Feed

The Co- planar feed is a very common technique used for coupling in dielectric resonator antennas. Here, figure 4.4 shows a monopole coupled to a co-planar loop. The coupling behavior of the co-planar loop is similar to coaxial probe, but the loop offers the advantage of being non-obtrusive. By moving the feed loop from the edge of the monopole to the center, one can couple into either . Co-planar waveguide (CPW) feeding technique is also referred as planar strip line feeding. CPW feeding technique more advantageous compared to other feeding techniques, because it is having the fallowing attractive features. They are 18



Lower radiation leakage



Less dispersion than micro-strip lines



Active devices can be mounted on top of the circuit like on micro-strip.

It can provide extremely high frequency response (100 GHz or more). Since connecting to CPW does not involve or require any parasitic discontinuities in the ground plane. The coplanar waveguide (CPW) is such a transmission line that can achieve high radiation efficiency demands. In addition, the CPW has lower loss than the micro-strip line. One promising application with the coplanar waveguide fed antenna techniques is that a fiber optics system can be integrated with the slot antenna. Recently, different types of CPW-fed slot antennas have been designed for wideband applications, achieving 50% bandwidth in a multi-slot design and 60% and width by optimizing a tuning stub As with micro-strip line excitation, slot antennas excited by coplanar waveguides also have bidirectional radiation characteristics.

19

Chapter 5 Parameters

20

5.1 Monopole Parameters The design parameters are as following.

5.1.1 Monopole Length Use the formula: Length (feet) = 234 / Frequency (MHz). 234 / 2500 = 0.09 feet (rounded to nearest 0.1 foot.) Your 4G cell phone 2500 MHz quarter wavelength wire monopole antenna needs to be 0.09 feet or about 1 inch in length. In our design ML=L/4.

5.1.2 Monopole Radius The 0.95-0.98 is the coefficient which is usually used to "shorten" the value of the length of the monopole as compared to the length of a "perfect" 1/2 wavelength long dipole and 1/4 wavelength long monopole. This is due to the capacitance created by the ends of the finite diameter of a practical monopole. In our design MR=0.7.

5.1.3 Ground Radius The monopole object is a monopole antenna mounted over a rectangular ground plane., where: d is the diameter of equivalent cylindrical monopole. r is the radius of equivalent cylindrical monopole. In our design GD=44mm.[5]

5.1.4 Ground Thickness The standard input impedance of a thin monopole antenna centered at 2.45GHz which uses a ground plane of radius λ/2. A general rule is the thickness of the monopole antenna determines the bandwidth of the antenna. In our design GT=1.8mm.

5.1.5 Frequency The

bandpass

filter,

when

integrated

with

a

CPW

wideband

antenna,

produces frequency agility with a wideband mode and a continuous narrowband mode. 21

In our design we operate at F=4.7GHz.

5.2 DESIGN PARAMTER

Table 1: Design Parameter

22

Chapter 6 Results and Future Work

23

6.1 Results of Switching Elements The work presents the switching of the elements by making some elements open and short.

6.1.1 Result 1: In this design we are making six elements open and six elements short.

Figure 6.1 Design 1

24

Figure 6.2 Radiation pattern 1

6.1.2 Result 2:

Figure 6.3 Design 2

25

Figure 6.4 Radiation pattern 2

6.1.3 Result3: .

Figure 6.5 Design 3

26

Figure 6.6 Radiation pattern 3

6.1.4 Result4:

Figure 6.7 Design 4

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Figure 6.8 Radiation pattern 4

6.1.5 Result5:

Figure 6.9 Design 5

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Figure 6.10 Radiation pattern 5

6.1.6 Result6:

Figure 6.11 Design 6

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Figure 6.12 Radiation pattern 6

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6.1.7 Result7:

Figure 6.13 Design 7

Figure 6.14 Radiation pattern 7

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6.1.8 Result8:

Figure 6.15 Design 8

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Figure 6.16 Radiation pattern 8

6.1.9 Result9:

Figure 6.17 Design 9

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Figure 6.18 Radiation pattern 9

6.1.10 Result10:

Figure 6.19 Design 10

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Figure 6.20 Radiation pattern 10

6.1.11 Result11:

Figure 6.21 Design 11

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Figure 6.22 Radiation pattern 11

6.3 Conclusion

Monopoles have been studied in this thesis their different radiation patterns have been recorded by making six elements sort and six elements open. By this we achieve beam steering in 380 degree.

6.4 Future Work 

Monopoles directivities will be increased by using Arrays.



Measurements of fabricated design will be carried out in future.

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 Someday monopoles may be common.

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References

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1. Energy efficient switched parasitic array antenna for 5g network and IoT by Ahmed Kausar Department of Electrical and Computer Engineering, Boise State University, Boise, USA 2.

Hani Mehrpouyan ,Department of Electrical and Computer Engineering, Boise

State University, Boise, USA ,Mathini Sellathurai School of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, U.K Rongrong QianSchool of Engineering and Physical Sciences, Heriot Watt University, Edinburgh, U.K ,Shafaq Kausar,Department of Electrical Engineering, National University of Sciences and Technology, Islamabad, Pakistan 3. Explain that Stuff. (2019). How do antennas and transmitters work?. [online] Available at: https://www.explainthatstuff.com/antennas.html [Accessed 6 Apr. 2019]. 5. S. Keyrouz and D. Caratelli, "Dielectric Resonator Antennas: Basic Concepts, Design

Guidelines,

and

Recent

Developments

at

Millimeter-Wave

Frequencies", International Journal of Antennas and Propagation, vol. 2016, pp. 1-20, 2016. Available: 10.1155/2016/6075680

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