Defected Ground Structure (DGS) Based Antennas

Debatosh Guha, PhD, is a Professor in Radio Physics and Electronics at the University of Calcutta, India. He co-edited Microstrip and Printed Antennas: New Trends, Techniques and Applications in 2010. Chandrakanta Kumar, PhD, is Head of the Electromagnetics Section at the Communication Systems Group of the U R Rao Satellite Centre in Bangalore, India. His professional focus is on the design and development of antenna systems for the Indian space program. Sujoy Biswas, PhD, is an Associate Professor at the Neotia Institute of Technology ­Management and Science. He is on the Board of Reviewers at a variety of journals, including IEEE Transactions on Antennas and Propagation.

• Preface xiAcknowledgments xv1 Introduction to DGS: The Concept and Evolution 11.1 Introduction 11.2 Evolution of DGS 21.3 Definition and Basic Concept 51.4 Geometries and Classification 61.4.1 Unit Cell DGS 71.4.1.1 Dumbbell-Shaped DGS 71.4.1.2 Variations of Dumbbell-Shaped DGS 81.4.1.3 Spiral-Shaped DGS 121.4.1.4 Variations of Spiral-Shaped DGS 131.4.1.5 H-Shaped DGS 141.4.1.6 U- and V-Shaped DGSs 151.4.1.7 Ring-Shaped DGS 151.4.1.8 Other DGS Geometries 161.4.1.9 Tunable DGS Geometries 181.4.2 Periodic Uniform DGS 181.4.3 Periodic Nonuniform DGS 201.4.4 Asymmetric DGS 221.5 An Outline of Applications 23References 242 Theoretical Analysis and Modeling 352.1 Introduction 352.2 LC and RLC Modeling 352.2.1 Equivalent Circuit Parameter Extraction 372.2.2 Utilization of the Extracted LC for n-Pole DGS Filter Design 41Trim Size: 6in x 9in Single Column Guha896180 ftoc.tex V1 - 10/10/2022 8:10pm Page vi[1][1] [1][1]vi Contents2.2.3 RLC Circuit Modeling 432.3 LC Circuit Modeling: Variants and Improvements 442.3.1 Pi-Type Equivalent Circuit 442.3.2 Modeling of Spiral DGS with Periodic Resonance 462.3.3 Modeling of DGS with Aperiodic Stopbands 512.3.4 Some Modifications in Modeling Approach 542.4 Transmission Line Modeling 552.5 Quasistatic Modeling 592.5.1 Microstrip Gap Model 622.5.2 Microstrip Cross Junction Model 632.5.3 Modeling of the Rest Current Paths 642.6 Modeling of Isolated DGS for Antenna applications 662.7 Comments on the Modeling Techniques 68References 693 DGS for Printed Antenna Feeds 733.1 Introduction 733.2 Impedance Matching of Antenna Feed Lines 733.3 Controlling the Harmonics in Printed Antennas 753.3.1 Suppression of Second Harmonic (2f 0) 773.3.2 Suppression up to Third Harmonic (3f 0) 793.3.3 Suppression up to Fourth Harmonic (4f 0) 843.4 Filtering Antenna Using DGS 863.5 Improved Isolation Between Antenna Ports 883.6 Improvement of Antenna Bandwidth 923.6.1 Lowering the Q-Factor 923.6.2 Adjusting Higher Resonances 943.7 Antenna Miniaturization 94References 984 DGS to Control Orthogonal Modes in a Microstrip Patch forCross-Pol Reduction 1034.1 Introduction 1034.2 Understanding of Radiating Modes in Microstrip Patches 1034.2.1 Rectangular Patch 1044.2.2 Circular Patch 1064.3 WhatWere the Known Methods to Deal with the Cross-PolarizedFields? 1104.4 Suppression of Cross-Polarized Fields by DGS Integration Technique:Coax-Fed Patches 112Trim Size: 6in x 9in Single Column Guha896180 ftoc.tex V1 - 10/10/2022 8:10pm Page vii[1][1] [1][1]Contents vii4.4.1 Controlling the OCDM and Cross-Polarized Radiations inE-Plane 1124.4.2 Controlling of TM21 Mode and Cross-Polarized Radiations in Circularand Elliptical Patches 1134.4.3 Controlling TM02 Mode in a Rectangular Patch and H-PlaneCross-Polarized Radiations 1164.4.4 Visualization of the Modal Fields and the Effect of the DGSs 1174.4.5 Universal DGS: Applicable to Both Circular and Rectangular PatchGeometries 1234.4.6 DGS for Triangular Microstrip Patch 1274.5 Suppression of Cross-Polarized Fields by DGS Integration Technique:Microstrip-Fed Patches 1284.6 RecentWorks and New Trends 1334.6.1 New DGS Geometries 1334.6.2 New Design Concept of Substrate Field Symmetry 1334.6.3 Reconfigurable Grid DGS 1364.7 New Endeavor: Addressing XP Issues Across Skewed RadiationPlanes 1384.8 Practical Aspects of DGS-Integrated Antennas 140References 1415 Multi Parametric Cross-Polar Sources and DGS-BasedSolution to All Radiation Planes 1455.1 Background and Introduction 1455.2 Mathematical Explanations of Cross-Polarized Fields 1465.2.1 Sources of Ex and Ey Components 1475.2.2 How to Combat Ey Components 1495.3 Detailed Investigations in to the XP Sources 1515.3.1 Rectangular Patch 1515.3.2 Square and Circular Patches 1595.4 DGS-Based Designs for Low XP in All Radiation Planes 1595.4.1 Design of Microstrip Line-Fed Circular Patch Antenna 1605.4.2 Design of a Coax-Fed Rectangular Patch 1615.4.3 Designing a Patch with Non-proximal DGS 1685.5 Conclusion 178References 1786 DGS-Based Low Cross-Pol Array Design andApplications 1816.1 Introduction 1816.2 Low Cross-Pol Microstrip Array Design 181Trim Size: 6in x 9in Single Column Guha896180 ftoc.tex V1 - 10/10/2022 8:10pm Page viii[1][1] [1][1]viii Contents6.2.1 Coax-Fed Microstrip Array 1826.2.2 Microstrip Line-Fed Array 1856.3 Array Design for Reduced Mutual Coupling 1936.4 DGS-Based Array for Different Applications 1936.4.1 Elimination of Scan Blindness 1946.4.2 Millimeter-Wave Imaging with Suppressed XP 1946.4.3 High-Performance Rectenna Array 1966.4.4 Enhancement of Scanning Range 197References 2027 DGS Based Mutual Coupling Reduction: Microstrip Array,5G/MIMO, and Millimeter Wave Applications 2057.1 Introduction 2057.2 Mutual Coupling Mechanisms 2067.2.1 Mutual Coupling Through Radiations 2067.2.2 Mutual Coupling by SurfaceWaves 2077.2.3 Coupling Through Ground Plane Currents 2087.3 Known Techniques to Control Mutual Coupling 2087.4 DGS Based Solutions to Mutual Coupling 2097.5 Major Applications 2177.5.1 Elimination of Scan Blindness in Large Arrays 2177.5.2 Enhancement of Scan Range in Phased Array 2187.5.3 DGS Based Compact Antennas for 5G/MIMO/MillimeterWaveApplications 2217.6 Conclusion 231References 2328 DGS Applied to Circularly Polarized Antenna Design 2398.1 Introduction 2398.2 Basic Principle of CP Generation in a Microstrip Patch 2398.3 Some Important Aspects and Challenges in CP Designs 2428.4 DGS Integrated Single-Fed CP Antenna Design 2438.4.1 Use of Slot-Type DGS 2438.4.2 Use of Fractal DGS 2458.4.3 Use of Grid DGS 2478.4.4 Use of PIN Switch Integrated Reconfigurable DGS 2498.5 DGS as a Supportive Component to CP Design 2528.5.1 DGS for Improved Surface Current 2528.5.2 DGS for Balanced Orthogonal Modes 2528.5.3 DGS for Optimizing CP Bandwidth 2548.5.4 DGS for Beam Squint Correction and Improved CP Quality 261Trim Size: 6in x 9in Single Column Guha896180 ftoc.tex V1 - 10/10/2022 8:10pm Page ix[1][1] [1][1]Contents ix8.6 Evolving Applications: DGS In SIW-Based CP Antennas 265References 2679 DGS Integrated Printed UWB Monopole Antennas 2719.1 Introduction 2719.2 Improved Impedance Bandwidth and Multiband Operation 2729.2.1 Improved Impedance Matching of UWB Antennas 2729.2.2 DGS Induced Resonances for Improved UWB Operation 2779.3 Band Notch Characteristics in UWB Antennas 2809.3.1 DGS Based UWB Antenna to Avoid Interference up to C-Band 2809.3.2 UWB Antenna for Multi-Notch Band Extending to X-Band 2869.4 Applications to Band Notch UWB MIMO Antennas 2889.5 Time Domain Behavior of DGS Based UWB Monopole 2939.6 Conclusion 295References 296Index 301