Space Antenna Handbook

Editors William A. Imbriale, Jet Propulsion Laboratory, California Institute of Technology, USA Steven (Shichang) Gao, Surrey Space Centre, UK Luigi Boccia, University of Calabria, Italy

Preface xvii

Acknowledgments xix

Acronyms xxi

Contributors xxv

1 Antenna Basics 1
Luigi Boccia and Olav Breinbjerg

1.1 Introduction 1

1.2 Antenna Performance Parameters 2

1.2.1 Reflection Coefficient and Voltage Standing Wave Ratio 2

1.2.2 Antenna Impedance 3

1.2.3 Radiation Pattern and Coverage 4

1.2.4 Polarization 6

1.2.5 Directivity 7

1.2.6 Gain and Realized Gain 8

1.2.7 Equivalent Isotropically Radiated Power 8

1.2.8 Effective Area 9

1.2.9 Phase Center 9

1.2.10 Bandwidth 9

1.2.11 Antenna Noise Temperature 9

1.3 Basic Antenna Elements 10

1.3.1 Wire Antennas 10

1.3.2 Horn Antennas 10

1.3.3 Reflectors 15

1.3.4 Helical Antennas 17

1.3.5 Printed Antennas 19

1.4 Arrays 26

1.4.1 Array Configurations 28

1.5 Basic Effects of Antennas in the Space Environment 30

1.5.1 Multipaction 30

1.5.2 Passive Inter-modulation 31

1.5.3 Outgassing 31

References 32

2 Space Antenna Modeling 36
Jian Feng Zhang, Xue Wei Ping, Wen Ming Yu, Xiao Yang Zhou, and Tie Jun Cui

2.1 Introduction 36

2.1.1 Maxwell’s Equations 37

2.1.2 CEM 37

2.2 Methods of Antenna Modeling 39

2.2.1 Basic Theory 39

2.2.2 Method of Moments 40

2.2.3 FEM 45

2.2.4 FDTD Method 49

2.3 Fast Algorithms for Large Space Antenna Modeling 54

2.3.1 Introduction 54

2.3.2 MLFMA 54

2.3.3 Hierarchical Basis for the FEM 62

2.4 Case Studies: Effects of the Satellite Body on the Radiation Patterns of Antennas 68

2.5 Summary 73

Acknowledgments 73

References 73

3 System Architectures of Satellite Communication, Radar, Navigation and Remote Sensing 76
Michael A. Thorburn

3.1 Introduction 76

3.2 Elements of Satellite System Architecture 76

3.3 Satellite Missions 77

3.4 Communications Satellites 77

3.4.1 Fixed Satellite Services 77

3.4.2 Broadcast Satellite Services (Direct Broadcast Services) 78

3.4.3 Digital Audio Radio Services 78

3.4.4 Direct to Home Broadband Services 78

3.4.5 Mobile Communications Services 78

3.5 Radar Satellites 79

3.6 Navigational Satellites 79

3.7 Remote Sensing Satellites 80

3.8 Architecture of Satellite Command and Control 80

3.9 The Communications Payload Transponder 80

3.9.1 Bent-Pipe Transponders 81

3.9.2 Digital Transponders 81

3.9.3 Regenerative Repeater 81

3.10 Satellite Functional Requirements 81

3.10.1 Key Performance Concepts: Coverage, Frequency Allocations 82

3.10.2 Architecture of the Communications Payload 82

3.10.3 Satellite Communications System Performance Requirements 83

3.11 The Satellite Link Equation 83

3.12 The Microwave Transmitter Block 84

3.12.1 Intercept Point 85

3.12.2 Output Backoff 86

3.12.3 The Transmit Antenna and EIRP 87

3.13 Rx Front-End Block 88

3.13.1 Noise Figure and Noise Temperature 88

3.14 Received Power in the Communications System’s RF Link 90

3.14.1 The Angular Dependencies of the Uplink and Downlink 91

3.15 Additional Losses in the Satellite and Antenna 91

3.15.1 Additional Losses due to Propagation Effects and the Atmosphere 91

3.15.2 Ionospheric Effects – Scintillation and Polarization Rotation 93

3.16 Thermal Noise and the Antenna Noise Temperature 93

3.16.1 The Interface between the Antenna and the Communications System 93

3.16.2 The Uplink Signal to Noise 94

3.17 The SNR Equation and Minimum Detectable Signal 94

3.18 Power Flux Density, Saturation Flux Density and Dynamic Range 95

3.18.1 Important Relationship between PFD and Gain State of the Satellite Transponder 95

3.19 Full-Duplex Operation and Passive Intermodulation 96

3.20 Gain and Gain Variation 96

3.21 Pointing Error 97

3.22 Remaining Elements of Satellite System Architecture 98

3.23 Orbits and Orbital Considerations 98

3.24 Spacecraft Introduction 100

3.25 Spacecraft Budgets (Mass, Power, Thermal) 101

3.25.1 Satellite Mass 101

3.25.2 Satellite Power 101

3.25.3 Satellite Thermal Dissipation 101

3.26 Orbital Mission Life and Launch Vehicle Considerations 102

3.27 Environment Management (Thermal, Radiation) 102

3.28 Spacecraft Structure (Acoustic/Dynamic) 103

3.29 Satellite Positioning (Station Keeping) 103

3.30 Satellite Positioning (Attitude Control) 104

3.31 Power Subsystem 104

3.32 Tracking, Telemetry, Command and Monitoring 105

References 105

4 Space Environment and Materials 106
J. Santiago-Prowald and L. Salghetti Drioli

4.1 Introduction 106

4.2 The Space Environment of Antennas 106

4.2.1 The Radiation Environment 107

4.2.2 The Plasma Environment 109

4.2.3 The Neutral Environment 110

4.2.4 Space Environment for Typical Spacecraft Orbits 111

4.2.5 Thermal Environment 111

4.2.6 Launch Environment 113

4.3 Selection of Materials in Relation to Their Electromagnetic Properties 117

4.3.1 RF Transparent Materials and Their Use 117

4.3.2 RF Conducting Materials and Their Use 117

4.3.3 Material Selection Golden Rules for PIM Control 118

4.4 Space Materials and Manufacturing Processes 118

4.4.1 Metals and Their Alloys 118

4.4.2 Polymer Matrix Composites 121

4.4.3 Ceramics and Ceramic Matrix Composites 125

4.5 Characterization of Mechanical and Thermal Behaviour 127

4.5.1 Thermal Vacuum Environment and Outgassing Screening 127

4.5.2 Fundamental Characterization Tests of Polymers and Composites 128

4.5.3 Characterization of Mechanical Properties 130

4.5.4 Thermal and Thermoelastic Characterization 131

Acknowledgements 131

References 131

5 Mechanical and Thermal Design of Space Antennas 133
J. Santiago-Prowald and Heiko Ritter

5.1 Introduction: The Mechanical–Thermal–Electrical Triangle 133

5.1.1 Antenna Product 134

5.1.2 Configuration, Materials and Processes 135

5.1.3 Review of Requirements and Their Verification 136

5.2 Design of Antenna Structures 136

5.2.1 Typical Design Solutions for Reflectors 136

5.2.2 Structural Description of the Sandwich Plate Architecture 143

5.2.3 Thermal Description of the Sandwich Plate Architecture 143

5.2.4 Electrical Description of the Sandwich Plate Architecture in Relation to Thermo-mechanical Design 144

5.3 Structural Modelling and Analysis 144

5.3.1 First-Order Plate Theory 145

5.3.2 Higher Order Plate Theories 148

5.3.3 Classical Laminated Plate Theory 148

5.3.4 Homogeneous Isotropic Plate Versus Symmetric Sandwich Plate 149

5.3.5 Skins Made of Composite Material 150

5.3.6 Honeycomb Core Characteristics 152

5.3.7 Failure Modes of Sandwich Plates 152

5.3.8 Mass Optimization of Sandwich Plate Architecture for Antennas 154

5.3.9 Finite Element Analysis 156

5.3.10 Acoustic Loads on Antennas 159

5.4 Thermal and Thermoelastic Analysis 166

5.4.1 The Thermal Environment of Space Antennas 166

5.4.2 Transverse Thermal Conductance Model of the Sandwich Plate 167

5.4.3 Thermal Balance of the Flat Sandwich Plate 168

5.4.4 Thermal Distortions of a Flat Plate in Space 169

5.4.5 Thermoelastic Stability of an Offset Parabolic Reflector 171

5.4.6 Thermal Analysis Tools 172

5.4.7 Thermal Analysis Cases 173

5.4.8 Thermal Model Uncertainty and Margins 173

5.5 Thermal Control Strategies 173

5.5.1 Requirements and Principal Design Choices 173

5.5.2 Thermal Control Components 174

5.5.3 Thermal Design Examples 176

Acknowledgements 177

References 178

6 Testing of Antennas for Space 179
Jerzy Lemanczyk, Hans Juergen Steiner, and Quiterio Garcia

6.1 Introduction 179

6.2 Testing as a Development and Verification Tool 180

6.2.1 Engineering for Test 180

6.2.2 Model Philosophy and Definitions 182

6.2.3 Electrical Model Correlation 190

6.2.4 Thermal Testing and Model Correlation 195

6.3 Antenna Testing Facilities 203

6.3.1 Far-Field Antenna Test Ranges 203

6.3.2 Compact Antenna Test Ranges 203

6.3.3 Near-Field Measurements and Facilities 212

6.3.4 Environmental Test Facilities and Mechanical Testing 220

6.3.5 PIM Testing 224

6.4 Case Study: SMOS 226

6.4.1 The SMOS MIRAS Instrument 227

6.4.2 SMOS Model Philosophy 231

6.4.3 Antenna Pattern Test Campaign 238

References 248

7 Historical Overview of the Development of Space Antennas 250
Antoine G. Roederer

7.1 Introduction 250

7.2 The Early Days 252

7.2.1 Wire and Slot Antennas on Simple Satellite Bodies 252

7.2.2 Antenna Computer Modelling Takes Off 254

7.2.3 Existing/Classical Antenna Designs Adapted for Space 259

7.3 Larger Reflectors with Complex Feeding Systems 262

7.3.1 Introduction 262

7.3.2 Multi-frequency Antennas 263

7.3.3 Large Unfurlable Antennas 271

7.3.4 Solid Surface Deployable Reflector Antennas 279

7.3.5 Polarization-Sensitive and Shaped Reflectors 282

7.3.6 Multi-feed Antennas 285

7.4 Array Antennas 297

7.4.1 Conformal Arrays on Spin-Stabilized Satellites 297

7.4.2 Arrays for Remote Sensing 298

7.4.3 Arrays for Telecommunications 302

7.5 Conclusions 306

Acknowledgements 307

References 307

8 Deployable Mesh Reflector Antennas for Space Applications: RF Characterizations 314
Paolo Focardi, Paula R. Brown, and Yahya Rahmat-Samii

8.1 Introduction 314

8.2 History of Deployable Mesh Reflectors 315

8.3 Design Considerations Specific to Mesh Reflectors 320

8.4 The SMAP Mission – A Representative Case Study 320

8.4.1 Mission Overview 320

8.4.2 Key Antenna Design Drivers and Constraints 322

8.4.3 RF Performance Determination of Reflector Surface Materials 327

8.4.4 RF Modeling of the Antenna Radiation Pattern 329

8.4.5 Feed Assembly Design 338

8.4.6 Performance Verification 340

8.5 Conclusion 341

Acknowledgments 341

References 341

9 Microstrip Array Technologies for Space Applications 344
Antonio Montesano, Luis F. de la Fuente, Fernando Monjas, Vicente GarcÍa, Luis E. Cuesta, Jennifer Campuzano, Ana Trastoy, Miguel Bustamante, Francisco Casares, Eduardo Alonso, David Álvarez, Silvia Arenas, José Luis Serrano, and Margarita Naranjo

9.1 Introduction 344

9.2 Basics of Array Antennas 345

9.2.1 Functional (Driving) Requirements and Array Design Solutions 345

9.2.2 Materials for Passive Arrays Versus Environmental and Design Requirements 347

9.2.3 Array Optimization Methods and Criteria 349

9.3 Passive Arrays 350

9.3.1 Radiating Panels for SAR Antennas 350

9.3.2 Navigation Antennas 354

9.3.3 Passive Antennas for Deep Space 361

9.4 Active Arrays 363

9.4.1 Key Active Elements in Active Antennas: Amplifiers 363

9.4.2 Active Hybrids 366

9.4.3 The Thermal Dissipation Design Solution 367

9.4.4 Active Array Control 369

9.4.5 Active Arrays for Communications and Data Transmission 370

9.5 Summary 383

Acknowledgements 383

References 384

10 Printed Reflectarray Antennas for Space Applications 385
Jose A. Encinar

10.1 Introduction 385

10.2 Principle of Operation and Reflectarray Element Performance 388

10.3 Analysis and Design Techniques 391

10.3.1 Analysis and Design of Reflectarray Elements 391

10.3.2 Design and Analysis of Reflectarray Antennas 393

10.3.3 Broadband Techniques 396

10.4 Reflectarray Antennas for Telecommunication and Broadcasting Satellites 400

10.4.1 Contoured-Beam Reflectarrays 400

10.4.2 Dual-Coverage Transmit Antenna 402

10.4.3 Transmit–Receive Antenna for Coverage of South America 405

10.5 Recent and Future Developments for Space Applications 414

10.5.1 Large-Aperture Reflectarrays 414

10.5.2 Inflatable Reflectarrays 415

10.5.3 High-Gain Antennas for Deep Space Communications 416

10.5.4 Multibeam Reflectarrays 418

10.5.5 Dual-Reflector Configurations 420

10.5.6 Reconfigurable and Steerable Beam Reflectarrays 424

10.5.7 Conclusions and Future Developments 428

Acknowledgments 428

References 429

11 Emerging Antenna Technologies for Space Applications 435
Safieddin Safavi-Naeini and Mohammad Fakharzadeh

11.1 Introduction 435

11.2 On-Chip/In-Package Antennas for Emerging Millimeter-Wave Systems 436

11.2.1 Recent Advances in On-Chip Antenna Technology 436

11.2.2 Silicon IC Substrate Limitations for On-Chip Antennas 437

11.2.3 On-Chip Antenna on Integrated Passive Silicon Technology 439

11.3 Integrated Planar Waveguide Technologies 441

11.4 Microwave/mmW MEMS-Based Circuit Technologies for Antenna Applications 445

11.4.1 RF/Microwave MEMS-Based Phase Shifter 447

11.4.2 Reflective-Type Phase Shifters for mmW Beam-Forming Applications 447

11.5 Emerging THz Antenna Systems and Integrated Structures 448

11.5.1 THz Photonics Techniques: THz Generation Using Photo-mixing Antennas 451

11.5.2 THz Generation Using a Photo-mixing Antenna Array 453

11.6 Case Study: Low-Cost/Complexity Antenna Technologies for Land-Mobile Satellite Communications 454

11.6.1 System-Level Requirements 454

11.6.2 Reconfigurable Very Low-Profile Antenna Array Technologies 454

11.6.3 Beam Steering Techniques 455

11.6.4 Robust Zero-Knowledge Beam Control Algorithm 457

11.6.5 A Ku-band Low-Profile, Low-Cost Array System for Vehicular Communication 458

11.7 Conclusions 462

References 462

12 Antennas for Satellite Communications 466
Eric Amyotte and LuÍs Martins Camelo

12.1 Introduction and Design Requirements 466

12.1.1 Link Budget Considerations 467

12.1.2 Types of Satellite Communications Antennas 469

12.1.3 Materials 469

12.1.4 The Space Environment and Its Design Implications 470

12.1.5 Designing for Commercial Applications 470

12.2 UHF Satellite Communications Antennas 471

12.2.1 Typical Requirements and Solutions 471

12.2.2 Single-Element Design 472

12.2.3 Array Design 473

12.2.4 Multipactor Threshold 473

12.3 L/S-band Mobile Satellite Communications Antennas 474

12.3.1 Introduction 474

12.3.2 The Need for Large Unfurlable Reflectors 474

12.3.3 Beam Forming 475

12.3.4 Hybrid Matrix Power Amplification 476

12.3.5 Feed Array Element Design 478

12.3.6 Diplexers 478

12.3.7 Range Measurements 479

12.4 C-, Ku- and Ka-band FSS/BSS Antennas 479

12.4.1 Typical Requirements and Solutions 479

12.4.2 The Shaped-Reflector Technology 480

12.4.3 Power Handling 481

12.4.4 Antenna Structures and Reflectors 481

12.4.5 Reflector Antenna Geometries 482

12.4.6 Feed Chains 491

12.5 Multibeam Broadband Satellite Communications Antennas 496

12.5.1 Typical Requirements and Solutions 496

12.5.2 SFB Array-Fed Reflector Antennas 497

12.5.3 FAFR Antennas 500

12.5.4 DRA Antennas 503

12.5.5 RF Sensing and Tracking 503

12.6 Antennas for Non-geostationary Constellations 504

12.6.1 Typical Requirements and Solutions 504

12.6.2 Global Beam Ground Links 505

12.6.3 High-Gain Ground Links 505

12.6.4 Intersatellite Links or Cross-links 506

12.6.5 Feeder Links 507

Acknowledgments 508

References 508

13 SAR Antennas 511
Pasquale Capece and Andrea Torre

13.1 Introduction to Spaceborne SAR Systems 511

13.1.1 General Presentation of SAR Systems 511

13.1.2 Azimuth Resolution in Conventional Radar and in SAR 512

13.1.3 Antenna Requirements Versus Performance Parameters 514

13.2 Challenges of Antenna Design for SAR 518

13.2.1 Reflector Antennas 518

13.2.2 Active Antennas and Subsystems 519

13.3 A Review of the Development of Antennas for Spaceborne SAR 534

13.3.1 TecSAR 534

13.3.2 SAR- Lupe 535

13.3.3 ASAR (EnviSat) 535

13.3.4 Radarsat 1 535

13.3.5 Radarsat 2 535

13.3.6 Palsar (ALOS) 535

13.3.7 TerraSAR-X 536

13.3.8 COSMO (SkyMed) 536

13.4 Case Studies of Antennas for Spaceborne SAR 539

13.4.1 Instrument Design 539

13.4.2 SAR Antenna 540

13.5 Ongoing Developments in SAR Antennas 544

13.5.1 Sentinel 1 544

13.5.2 Saocom Mission 544

13.5.3 ALOS 2 545

13.5.4 COSMO Second Generation 545

13.6 Acknowledgments 546

References 546

14 Antennas for Global Navigation Satellite System Receivers 548
Chi-Chih Chen, Steven (Shichang) Gao, and Moazam Maqsood

14.1 Introduction 548

14.2 RF Requirements of GNSS Receiving Antenna 551

14.2.1 General RF Requirements 551

14.2.2 Advanced Requirements for Enhanced Position Accuracy and Multipath Signal Suppression 556

14.3 Design Challenges and Solutions for GNSS Antennas 561

14.3.1 Wide Frequency Coverage 562

14.3.2 Antenna Delay Variation with Frequency and Angle 562

14.3.3 Antenna Size Reduction 567

14.3.4 Antenna Platform Scattering Effect 568

14.4 Common and Novel GNSS Antennas 572

14.4.1 Single-Element Antenna 572

14.4.2 Multi-element Antenna Array 580

14.5 Spaceborne GNSS Antennas 582

14.5.1 Requirements for Antennas On Board Spaceborne GNSS Receivers 582

14.5.2 A Review of Antennas Developed for Spaceborne GNSS Receivers 584

14.6 Case Study: Dual-Band Microstrip Patch Antenna for Spacecraft Precise Orbit Determination Applications 586

14.6.1 Antenna Development 586

14.6.2 Results and Discussions 588

14.7 Summary 591

References 592

15 Antennas for Small Satellites 596
Steven (Shichang) Gao, Keith Clark, Jan Zackrisson, Kevin Maynard, Luigi Boccia, and Jiadong Xu

15.1 Introduction to Small Satellites 596

15.1.1 Small Satellites and Their Classification 596

15.1.2 Microsatellites and Constellations of Small Satellites 597

15.1.3 Cube Satellites 598

15.1.4 Formation Flying of Multiple Small Satellites 599

15.2 The Challenges of Designing Antennas for Small Satellites 600

15.2.1 Choice of Operating Frequencies 600

15.2.2 Small Ground Planes Compared with the Operational Wavelength 601

15.2.3 Coupling between Antennas and Structural Elements 601

15.2.4 Antenna Pattern 602

15.2.5 Orbital Height 602

15.2.6 Development Cost 602

15.2.7 Production Costs 602

15.2.8 Testing Costs 602

15.2.9 Deployment Systems 603

15.2.10 Volume 603

15.2.11 Mass 603

15.2.12 Shock and Vibration Loads 603

15.2.13 Material Degradation 603

15.2.14 Atomic Oxygen 603

15.2.15 Material Outgassing 604

15.2.16 Creep 604

15.2.17 Material Charging 604

15.2.18 The Interaction between Satellite Antennas and Structure 604

15.3 Review of Antenna Development for Small Satellites 606

15.3.1 Antennas for Telemetry, Tracking and Command (TT&C) 606

15.3.2 Antennas for High-Rate Data Downlink 609

15.3.3 Antennas for Global Navigation Satellite System (GNSS) Receivers and Reflectometry 615

15.3.4 Antennas for Intersatellite Links 618

15.3.5 Other Antennas 619

15.4 Case Studies 621

15.4.1 Case Study 1: Antenna Pointing Mechanism and Horn Antenna 621

15.4.2 Case Study 2: X-band Downlink Helix Antenna 623

15.5 Conclusions 627

References 628

16 Space Antennas for Radio Astronomy 629
Paul F. Goldsmith

16.1 Introduction 629

16.2 Overview of Radio Astronomy and the Role of Space Antennas 629

16.3 Space Antennas for Cosmic Microwave Background Studies 631

16.3.1 The Microwave Background 631

16.3.2 Soviet Space Observations of the CMB 632

16.3.3 The Cosmic Background Explorer (COBE) Satellite 633

16.3.4 The Wilkinson Microwave Anisotropy Probe (WMAP) 635

16.3.5 The Planck Mission 637

16.4 Space Radio Observatories for Submillimeter/Far-Infrared Astronomy 641

16.4.1 Overview of Submillimeter/Far-Infrared Astronomy 641

16.4.2 The Submillimeter Wave Astronomy Satellite 643

16.4.3 The Odin Orbital Observatory 646

16.4.4 The Herschel Space Observatory 648

16.4.5 The Future: Millimetron, CALISTO, and Beyond 650

16.5 Low-Frequency Radio Astronomy 652

16.5.1 Overview of Low-Frequency Radio Astronomy 652

16.5.2 Early Low-Frequency Radio Space Missions 653

16.5.3 The Future 655

16.6 Space VLBI 655

16.6.1 Overview of Space VLBI 655

16.6.2 HALCA 656

16.6.3 RadioAstron 658

16.7 Summary 658

Acknowledgments 660

References 660

17 Antennas for Deep Space Applications 664
Paula R. Brown, Richard E. Hodges, and Jacqueline C. Chen

17.1 Introduction 664

17.2 Telecommunications Antennas 665

17.3 Case Study I – Mars Science Laboratory 666

17.3.1 MSL Mission Description 666

17.3.2 MSL X-band Antennas 668

17.3.3 MSL UHF Antennas 676

17.3.4 MSL Terminal Descent Sensor (Landing Radar) 680

17.4 Case Study II – Juno 681

17.4.1 Juno Mission Description 681

17.4.2 Telecom Antennas 682

17.4.3 Juno Microwave Radiometer Antennas 684

Acknowledgments 692

References 693

18 Space Antenna Challenges for Future Missions, Key Techniques and Technologies 695
Cyril Mangenot and William A. Imbriale

18.1 Overview of Chapter Contents 695

18.2 General Introduction 696

18.3 General Evolution of Space Antenna Needs and Requirements 697

18.4 Develop Large-Aperture Antennas 699

18.4.1 Problem Area and Challenges 699

18.4.2 Present and Expected Future Space Missions 700

18.4.3 Promising Antenna Concepts and Technologies 702

18.5 Increase Telecommunication Satellite Throughput 707

18.5.1 Problem Area and Challenges 707

18.5.2 Present and Expected Future Space Missions 707

18.5.3 Promising Antenna Concepts and Technologies 708

18.6 Enable Sharing the Same Aperture for Multiband and Multipurpose Antennas 709

18.6.1 Problem Area and Challenges 709

18.6.2 Present and Expected Future Space Missions 710

18.6.3 Promising Antenna Concepts and Technologies 710

18.7 Increase the Competitiveness of Well-Established Antenna Products 710

18.7.1 Problem Area and Challenges 710

18.7.2 Present and Expected Future Space Missions 711

18.7.3 Promising Antenna Concepts and Technologies 712

18.8 Enable Single-Beam In-Flight Coverage/Polarization Reconfiguration 713

18.8.1 Problem Area and Challenges 713

18.8.2 Present and Expected Future Space Missions 714

18.8.3 Promising Antenna Concepts and Technologies 714

18.9 Enable Active Antennas at Affordable Cost 715

18.9.1 Problem Area and Challenges 715

18.9.2 Present and Expected Future Space Missions 717

18.9.3 Promising Antenna Concepts and Technologies 718

18.10 Develop Innovative Antennas for Future Earth Observation and Science Instruments 724

18.10.1 Problem Area and Challenges 724

18.10.2 Present and Expected Future Space Missions 725

18.10.3 Promising Antenna Concepts and Technologies 729

18.11 Evolve Towards Mass Production of Satellite and User Terminal Antennas 732

18.11.1 Problem Area and Challenges 732

18.11.2 Present and Expected Future Space Missions 732

18.11.3 Promising Antenna Concepts and Technologies 732

18.12 Technology Push for Enabling New Missions 734

18.12.1 Problem Area and Challenges 734

18.12.2 Promising Antenna Concepts and Technologies 734

18.13 Develop New Approaches for Satellite/Antenna Modelling and Testing 735

18.13.1 Problem Area and Challenges 735

18.13.2 Promising Antenna Concepts and Technologies 736

18.14 Conclusions 737

Acronyms 738

Acknowledgements 740

References 740

Index 741