Reconfigurable Circuits and Technologies for Smart Millimeter-Wave Systems (EuMA High Frequency Technologies Series)

Description

Get up to speed on the modelling, design, technologies, and applications of tunable circuits and reconfigurable mm-wave systems. Coverage includes smart antennas and frequency-agile RF components, as well as a detailed comparison of three key technologies for the design of tunable mm-wave circuits: CMOS, RF MEMS, and microwave liquid crystals, and measurement results of state-of-the-art prototypes. Numerous examples of tunable circuits and systems are included that can be practically implemented for the reader's own needs. Ideal for graduate students studying RF/microwave engineering, and researchers and engineers involved in circuit and system design for new communication platforms such as mm-wave 5G and beyond, high-throughput satellites in GSO, and future satellite constellations in MEO/LEO, as well as for automotive radars, security and biomedical mm-wave systems. Cover Half-title Series information Title page Copyright information Contents List of Contributors Preface List of Abbreviations 1 Introduction and Motivation 1.1 Evolution of Mobile Communications 1.1.1 Major Drivers Influencing the Growth of Future Mobile Traffic 1.1.2 5G Activities, Vision, and Objectives 1.1.3 Spectrum Allocation 1.1.4 Key Technology Drivers 1.2 Evolution and Trends in Satellite Communications Technology 1.2.1 High-Throughput Satellites in Geostationary and Medium Earth Orbits 1.2.2 Low Earth Orbit High-Throughput Satellite Constellations 1.2.3 Evolving High-Altitude Platform Stations 1.2.4 Satellite Markets and Perspective 1.2.5 Interoperable Satellite Networks 1.2.6 Toward Hybrid Terrestrial 5G/6G-Satellite Networks 1.3 Technologies References 2 Reconfigurable Devices and Smart Antennas 2.1 Millimeter-Wave Communication 2.2 Smart Antenna Systems 2.2.1 Basics of Electronically Steerable Antennas 2.2.2 Implementation of Electronically Steerable Antennas 2.2.3 Feeding Networks 2.2.4 G/T and Signal-to-Noise Ratio 2.2.5 Antenna Efficiency 2.2.6 Phase Shifters for Electronically Steerable Antennas 2.3 Tunable Filter 2.3.1 Impedance Matching 2.3.2 Variable Attenuators 2.4 Technologies for Tunable Components 2.4.1 Semiconductors 2.4.2 Microelectromechanical Systems 2.4.3 Functional Materials 2.4.3.1 Atomic Polarization 2.4.3.2 Dipolar Polarization 2.4.3.3 Spintronics References 3 CMOS and BiCMOS Technologies 3.1 Introduction 3.2 Fundamentals of CMOS and BiCMOS Technologies for Millimeter Waves 3.2.1 Back-End-of-Line of Current CMOS/BiCMOS Technologies 3.2.1.1 Technologies with High Density of Integration 3.2.2 Basic Components in RF Design Kits 3.2.2.1 Active Elements MOS Transistor The Bipolar Transistor 3.2.2.2 Passive Elements MOM Capacitor Transmission Lines Microstrip Lines Slow-Wave Transmission Lines: S-CPW and S-CPS Microstrip Lines and S-CPW Comparison 3.3 Tunable Components 3.3.1 Varactors 3.3.2 Switches 3.3.2.1 Basic Principle at RF Frequencies 3.3.2.2 Lumped Switches 3.3.2.3 Traveling-Wave Switches 3.3.3 Digitally Tunable Capacitance 3.3.4 Tunable Transmission Lines 3.3.4.1 Needs and Principles Needs What Does Tunable Transmission Line Mean? Switched Lines and Loaded Lines 3.3.4.2 Loaded-Lines Design Bragg Frequency Slow-Wave Effect Loaded-Line Quality Factor Implementation in Silicon Technologies 3.3.4.3 Mixed Switched and Loaded Lines 3.4 Applications 3.4.1 Design Flow 3.4.2 Phase Shifters 3.4.2.1 Basic Principles, Challenges at Millimeter-Waves, and Figures of Merit Basic Principles Figure of Merit and Challenges at Millimeter-Waves 3.4.2.2 Passive Phase Shifters 3.4.2.3 Continuous Tuning Loaded-Line Phase Shifter 3.4.2.4 Continuous Tuning Reflection-Type Phase Shifter Principle 3-dB Coupler Reflective Load 3.4.2.5 Digital Tuning (Switched) Phase Shifters 3.4.2.6 Mixed Digital/Continuous Tuning Phase Shifters 3.4.2.7 State-of-the-Art 3.4.3 Voltage-Controlled Oscillators 3.4.3.1 Basic Principles, Challenges at Millimeter-Waves, and Figures of Merit Principle Issues in Millimeter-Wave Design Figures of Merit 3.4.3.2 Architectures for Millimeter-Waves Lumped LC-Tank VCOs Distributed VCOs 3.4.3.3 State-of-the-Art and Trends 3.5 Challenges and Perspectives 3.5.1 Impedance Tuner 3.5.2 Multiband Distributed and Tapered Standing-Wave Oscillators 3.6 Conclusion References 4 RF MEMS Technology 4.1 Introduction 4.2 Fundamentals of RF MEMS for Millimeter-Wave Frequencies 4.2.1 Electromechanical Behavior of RF MEMS Switches 4.2.2 Millimeter-Wave MEMS Technologies 4.2.2.1 CMOS-Based Technologies: IHP 4.2.2.2 MEMS-Based Technologies: CEA-Leti 4.2.2.3 Dedicated Technologies: FBK 4.3 Millimeter-Wave MEMS Switches 4.3.1 Up-State Capacitance 4.3.1.1 Series Switch 4.3.1.2 Shunt Switch 4.3.2 Down-State Resistance 4.3.2.1 Series Switch 4.3.2.2 Shunt Switch 4.3.3 Down-State Capacitance 4.3.3.1 Series Switch 4.3.3.2 Shunt Switch 4.3.4 Suspended Transmission Line Section 4.3.4.1 Series Switch 4.3.4.2 Shunt Switch 4.3.5 Guidelines for Millimeter-Wave Switches Design 4.3.5.1 Series Switch 4.3.6 Broadband RF MEMS Switch 4.3.7 Narrowband RF MEMS Switch 4.4 MEMS Varactors 4.4.1 Analog MEMS Varactor 4.4.2 Digital Varactor 4.5 Phase Shifters 4.5.1 Switched-Line Phase Shifters 4.5.2 Distributed MEMS Phase Shifter 4.5.3 Slow-Wave MEMS Phase Shifters 4.5.4 Reflection Type Phase Shifter 4.5.5 Millimeter-Wave Phase Shifters State-of-the-Art 4.6 Switched Circuits 4.6.1 60-77 GHz Switchable Low-Noise Amplifier 4.6.2 Dual-Band Voltage-Controlled Oscillator 4.6.3 Reconfigurable Filters 4.7 Challenges and Perspectives References 5 Microwave Liquid Crystal Technology 5.1 Introduction to Microwave Liquid Crystal Technology 5.1.1 Performance Metric of Microwave LCs Hybrid Biasing SchemeTo make use of the LC's anisotropic nature, the orientation of the LC molecules must be controlled by means of electrostatic fields. The simplest biasing scheme can be explained by means of a parallel-plate capacitor. Beside the pair of electrodes, an additional pair of alignment layers is required to prealign the LC molecules into their initial state in parallel to the alignment layers (perpendicular to the RF field) by means of the surface anchoring forces in analogy to LC displays. The effect of polyimide alignment layers on the LC tuning efficiency is analyzed in [14, 23, 51]. Response TimeThe most critical parameter for reconfigurable LC devices is tuning speed or response time, which is defined as the time interval required to reach an equilibrium state of LC devices [14, 23, 26, 40, 52-54]. This will be explained for the aforementioned LC-filled parallel-plate capacitor. When a bias voltage Vb is applied, the LC directors start to change their orientation from the initial state (perpendicular to due to the alignment layers) toward the field lines of the electrostatic bias field , until they are nearly perpendicular between the alignment layers (nearly in parallel to ) for Vb Vsat. The time it takes is the rise or switch-on response time(5.4)with the threshold voltage(5.5)The more critical parameter for reconf... Elastic PropertiesIn general, changing the orientation of long and stiff nematic LC molecules by an electrostatic field within a thin LC cell capacitor of 1-5 ?m thickness implies relatively slow switch-off response times ?off in the range of 3.2 ms up to 80 ms for GT3 and 16 ms up to 410 ms for TUD-566 according to Eq. (5.6) and Figure 5.1, compared to a fast shift of the ion from and back to the lattice center of a 1 to 5 ?m thick ferroelectric capacitor, which is in the nanosecond or even picosecond range. But this slowness of nematic LCs implies excellent linear behavior [13-15].Taking into account some uncertainties of K11 and ?rot in Table 5.1 and in the determination of the ''real'' LC layer height, the foregoing theoretical values f... 5.1.2 Applications of Microwave LCs 5.1.3 Perspectives of Microwave LC Technology 5.2 Fundamentals of LC Material for Microwaves 5.2.1 Properties of LCs 5.2.1.1 Order Parameter of a Bulk of LC 5.2.1.2 Electromagnetic Properties of LC Materials 5.2.1.3 Frequency and Temperature Dependency of the Permittivity 5.2.2 The Elastic Continuum Theory of LCs 5.2.3 Orientation Mechanisms of LCs and Biasing Schemes 5.2.3.1 Prealignment by Surface Anchoring 5.2.3.2 LC Tuning by Electromagnetic Fields and Basic Biasing Concept 5.2.3.3 Electrical Biasing Schemes for MLC Devices 5.3 Microwave Characterization of LCs 5.3.1 Narrowband Cavity Perturbation Method 5.3.1.1 Modeling Cavities for Material Parameter Extraction 5.3.1.2 Ansatz and Numerical Extraction 5.3.1.3 Measurement Setup and Results 5.3.2 Broadband Coaxial Transmission Line Method 5.3.2.1 Parameter Extraction 5.3.2.2 Measurement Setup 5.3.3 Terahertz Material Characterization 5.3.3.1 Material Characterization in a Free-Space Setup 5.3.4 LC Characterization Results and Further Development 5.4 Liquid Crystal-Based Delay Line Phase Shifter Topologies 5.4.1 Tunable Low-Profile Planar Transmission Line Phase Shifter 5.4.1.1 Tunable Microstrip Line 5.4.1.2 Grounded Coplanar Waveguide Loaded with Fast Tuning LC Varactors 5.4.2 Tunable High-Performance Metallic Waveguide Phase Shifter 5.4.3 Tunable Dielectric Waveguide Phase Shifter 5.4.3.1 Tunable Subwavelength Fiber and Dielectric Waveguide 5.4.3.2 Parallel-Plate Waveguide with LC-Filled Dielectric Slab 5.4.4 Monolithic Integration of LC Phase Shifter with Different Technologies 5.4.4.1 LC-Based Low-Temperature Co-fired Ceramic Phase Shifter 5.4.4.2 LC-Reflection-Type Phase Shifter in MEMS Technology 5.4.4.3 LC-Based Complementary Metal-Oxide-Semiconductor Phase Shifter 5.4.4.4 LC-Based Nanowire Membrane Phase Shifter 5.4.5 Comparison of LC-Based Phase Shifters 5.5 Tunable Resonators and Filters 5.5.1 SIW Bandpass Filter 5.5.2 Waveguide Filter 5.5.3 NRD Filter 5.5.4 Comparison of Tunable Filters 5.6 Electronically Steerable Antennas 5.6.1 Frequency-Agile Antennas 5.6.2 Polarizer and Polarization-Agile Antennas 5.6.3 Deflecting Gratings and Lens Antennas 5.6.4 Mixed Beam-Switching and Beam-Steering Antennas 5.6.5 Beam-Steering Reflectarrays 5.6.6 Beam-Steering Leaky-Wave Antennas 5.6.7 Beam-Steering Phased Arrays 5.6.7.1 Flat-Panel Beam-Steering Antenna Array 5.6.7.2 Electronic Beam-Steering Horn Antenna Array 5.6.7.3 Fully Dielectric Rod Antenna Array 5.7 LC-Based Tunable Power Divider, Metamaterials, and Surfaces 5.7.1 Tunable Power Divider and RF Switches 5.7.2 Tunable Metamaterials, Frequency-Selective and High-Impedance Surfaces References Appendix 1 Satellite History, Orbits, and Classification A1.1 Early History of Satellites A1.2 Satellite Orbits A1.3 Effective Aperture, Gain, and Half-Power Beam Width of Antennas A1.4 Comparison of Satellite Systems in Different Orbits A1.4.1 Covered Area A1.4.2 Signal Delay A1.4.3 Received Power for a Satellite-Earth Path A1.5 Examples of Satellite Systems in Different Orbits A1.6 Classification of Satellite Services Appendix 2 Multiphysical Modeling of Nematic Liquid Crystals A2.1 Director Dynamics A2.2 Laplace Equation of Anisotropic Continuous Materials A2.3 Computation of Waveguide Modes References Index