Metamaterial Surface Plasmon Based Transmission Lines and Antennas

120 Pages·2017·6.94 MB·English

Metamaterial Surface Plasmon Based
Transmission Lines and Antennas

Amin Kianinejad

B. Sc., Shiraz University of Technology, Iran
M. Sc., Sharif University of Technology, Iran

A THESIS SUBMITTED
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
NATIONAL UNIVERSITY OF SINGAPORE

2017

Supervisors:
PROFESSOR CHEN ZHI NING
ASSOCIATE PROFESSOR QIU CHENG-WEI

Examiners:
PROFESSOR YEO TAT SOON
ASSOCIATE PROFESSOR CHEN XUDONG
PROFESSOR FRANCISCO JOSE GARCIA VIDAL, AUTONOMOUS UNIVERSITY OF
MADRID
Declaration

I, Amin Kianinejad declare that the thesis submitted is my own original work. I declare
that the thesis contains research reported in co-authored work that has been published,
accepted for publication, or submitted for publication. I declare that the thesis does not contain
material which has been accepted, or submitted, for any other degree or diploma at a university or
other institution of higher learning.

Signed:

Date:

January 2017
ii

Acknowledgment

Firstly, I would like to express my sincere gratitude to my advisors Prof. Zhi Ning Chen
and Prof. Cheng-Wei Qiu for the continuous support of my Ph.D study and related
research, for their patience, motivation, and immense knowledge. Their guidance helped
me in all the time of research and writing of this thesis.
Besides my advisor, I would like to thank the rest of my thesis advisory committee: Prof.
Tat Soon Yeo, Prof. Xudong Chen, and Prof. Minghui Hong, for their insightful comments
and encouragement, but also for the hard question which incented me to widen my research
from various perspectives.
A special thanks to my family. Words cannot express how grateful I am to my mother,
Nasrin, my father, Abodlrahim and my brothers Iman and Mohammad for all of the
sacrifices that they’ve made on my behalf. Their prayer for me was what sustained me thus
far. I would also like to thank all of my friends in MMIC lab, specially, Wei Liu, Srien
Sithara, Andong Huang, Yuanyan Su and Ashraf Adam Salih who supported me in writing,
and incented me to strive towards my goal. I would also like to thank my friends outside
NUS specially Sajjad Seifozzakerini, Hossein Dehghani Tafti, Mohammad Danesh and
Rasool Maghareh who made the journey more rewarding and enjoyable.
iii

Summary

Current electronic systems are composed of the guiding wave-based electronic devices
and components with double-metal configurations. Recently, the Spoof Surface Plasmon
(SSP) modes have been proposed as a novel platform for electronic circuits. With their
high field confinement, the SSPs do not suffer from the compactness limitations of
traditional circuits and are capable of playing the crucial role of an alternative platform for
the future generation of electronic circuits and electromagnetic systems. Despite the vast
number of research effort that have been devoted to the SSP modes, a deep theoretical
study and a reliable and repeatable modeling for the SSP structures are strongly demanded.
Here, we tackle the quest by elaborating the basic requirements for the implementation of
the SSP modes in microwave circuits to enable the SSP-based circuit components designs.
In Chapter 1, the background of this study is discussed.
The equivalent circuit models for the electromagnetic structures are important for
analysis and the design of their characteristics. In Chapter 2, the equivalent circuit models
are presented for the characterization of the SSP structures and to serve as an insightful
guideline to design the SSP-based circuits.
To efficiently excite the SSP modes, it is necessary to couple the SSP structures to the
guiding mode-based microwave sources and transmission lines. In Chapter 3, a new type of
efficient transitions is developed for the connection of the SSP cells to the conventional
TLs in order to form slow wave transmission-lines (SW-TLs). The simulation and
experiments verify that the proposed SW-TL achieves as low as half of the ohmic loss of
the traditional counterparts. Moreover, the low cross-talk between the proposed SW-TLs is
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numerically and experimentally substantiated to be up to 10 dB lower than that between the
conventional microstrip TLs.
In Chapter 4, a spoof plasmon (SP)-based slow-wave antenna feeding network is
proposed, experimentally verified and exploited to excite the fundamental TE mode of
dielectric resonator antennas (DRAs). The simulation and measurement evidence the
unique features of TE mode such as the lower thickness-dependency of the resonant
01δ
frequencies, ultra-compactness, and horizontally polarized omnidirectional radiation
pattern.
In Chapter 5, a single-layered leaky-wave antenna (SL-LWA) using a meander SSP
structure is presented and the simulation and experiment evidence the consistent gain
variation less than 2.5 dB of scanning beams within the 10-dB reflection bandwidth of
10.4-24.5 GHz (or 80%). In addition, the proposed antenna provides the wideband
broadside radiation with 1-dB gain variation within the frequency range of 16.5-17.2 GHz
(or 4.2%).
In Chapter 6, the future of this research is discussed.
v

Table of Contents
Declaration ………………………………………………………........………..………i
Acknowledgment……………………………...…………………….….…..….………ii
Summary…………………………………………...………………….…..….………iii
List of Tables………………………………………………………………….…..…viii
List of Figures……….………………………………………………………..…..…...ix
List of Abbreviations………………………………………………………..………...xi
List of Symbols……………………………………………………………...………..xii
1 Introduction ........................................................................................................... 1
1.1 Physical concept of spoof surface plasmon modes ............................................. 2
1.2 Surface wave-based single line transmission lines ............................................. 4
1.3 SSP based microwave components ..................................................................... 5
1.4 Motivation and organization of this thesis .......................................................... 6
1.5 My published papers related to this work ........................................................... 8
2 Spoof Surface Plasmon Modes Modeling Using Circuit Elements ................. 10
2.1 Field confinement of SSP modes ...................................................................... 11
2.2 Principles of circuit modeling ........................................................................... 16
2.3 Equivalent circuit models for SSP cells ............................................................ 18
vi

2.3.1 U-shaped SSP cells ........................................................................................... 19
2.3.2 Symmetric SSP cells ......................................................................................... 22
2.3.3 Meander SSP cells ............................................................................................ 23
2.4 SSP-based circuit design using circuit models ................................................. 26
2.5 Conclusion ........................................................................................................ 30
3 SSP-Based Transmission Lines (TLs) ............................................................... 32
3.1 Conversion of SSP modes to guided waves ...................................................... 32
3.1.1 Polarization matching ....................................................................................... 32
3.1.2 Momentum Matching ........................................................................................ 34
3.1.3 Impedance matching ......................................................................................... 34
3.2 Transition design from SSPs to conventional TLs ............................................ 36
3.2.1 Transition from U-shaped cells to microstrip TLs ............................................ 36
3.2.2 Transition from the symmetric cells to CPW lines ........................................... 44
3.2.3 Transition from meander cells to CPWs ........................................................... 46
3.3 Loss in SW-TLs ................................................................................................ 47
3.3.1 The leaky loss ................................................................................................... 48
3.3.2 Ohmic loss ........................................................................................................ 49
3.3.3 Equivalent circuit models of lossy SW-TLs: .................................................... 49
3.4 Mutual coupling between SW-TLs ................................................................... 52
3.5 Conclusion ........................................................................................................ 54
4 Spoof Surface Plasmon Excitation of Dielectric Resonator Antennas ........... 56
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4.1 Resonance modes of cylindrical DRAs ............................................................ 56
4.2 Feeding configuration design ............................................................................ 59
4.3 Excitation of the TE modes ............................................................................... 61
4.4 The radiation performance ................................................................................ 63
4.5 Conclusion ........................................................................................................ 65
5 Spoof surface plasmon-based Leaky-Wave Antenna (LWA) ......................... 66
5.1 Radiation mechanism ........................................................................................ 68
5.1.1 Single-layered leaky-wave antenna .................................................................. 68
5.1.2 SL-LWA without 2nd converter ......................................................................... 70
5.1.3 Comparison with other LW structures similar to SL-LWA .............................. 71
5.1.4 Effect of dielectric and metal ............................................................................ 73
5.2 Design procedure and optimization .................................................................. 75
5.3 Experimental verification .................................................................................. 78
5.4 Conclusion ........................................................................................................ 81
6 Future Work ........................................................................................................ 82
6.1 Spoof surface plasmon modes in antenna design .............................................. 83
6.2 Spoof surface plasmon-based circuit design ..................................................... 84
A Excitation of TE-dominant higher order modes in DRAs ............................... 86
B Farfield Radiation Pattern Results of SL-LWA ............................................... 91
References ............................................................................................................ 94
viii

List of Tables
Table 2.1. Circuit element parameters of the U-shaped SSP cells ................................ 19
Table 2.2- Equivalent circuit elements for six symmetric SSP cells ............................. 23
Table 2.3- Circuit element parameters for meander SSP cells. ..................................... 27
Table 2.4- Four sets of resistors. ................................................................................... 29
Table 3.1. Relation between parameters of strip connector .......................................... 37
Table 3.2. Five parameter sets for mode converter ....................................................... 41
Table 3.3. Parameters of U-shaped SW–TL.................................................................. 41
Table 3.4- Five parameter sets for mode converter. ...................................................... 44
Table 3.5- Geometrical parameters of two SW-TLs ..................................................... 49
ix

List of Figures
Fig. 2.1. A symmetric SSP cell. .................................................................................... 11
Fig. 2.2. Dispersion of SSP cells. .................................................................................. 13
Fig. 2.3. Field distribution of SSP cells. ........................................................................ 14
Fig. 2.4. The circuit model for U-shaped SSP cells. ..................................................... 18
Fig. 2.5. The circuit model for symmetric SSP cells. .................................................... 22
Fig. 2.6. The circuit model for meander SSP cells. ....................................................... 24
Fig. 2.7. Meander SSP cells: dispersion curves and characteristic impedance. ............ 25
Fig. 2.8. Loading design for symmetric SW-TLs.......................................................... 28
Fig. 2.9. Reflection results from loaded SW-TLs. ........................................................ 29
Fig. 3.1. Polarization transformation of mode converter............................................... 33
Fig. 3.2. Dispersion conversion. .................................................................................... 34
Fig. 3.3. Impedance matching of mode converter. ........................................................ 35
Fig. 3.4. Mode converter design for U-shaped SSP cells. ............................................. 36
Fig. 3.5. Mode converter design for U-shaped SSP cells. ............................................. 38
Fig. 3.6. Effect of ground connector. ........................................................................... 39
Fig. 3.7. Mode converter design for U-shaped SSP cells. ............................................. 40
Fig. 3.8. Experimental evaluation of U-shaped SW-TL. ............................................... 42
Fig. 3.9. Mode converter design for symmetric SSP cells. ........................................... 43
Fig. 3.10. S-parameter results of symmetric SW-TL. ................................................... 45
Fig. 3.11. Meander SW-TL. .......................................................................................... 46
Fig. 3.12. Loss in symmetric SW-TLs. ......................................................................... 48