Terahertz Antenna Technology for Imaging and Sensing Applications

Description

This book covers terahertz antenna technology for imaging and sensing, along with its various applications. The authors discuss the use of terahertz frequency and photoconductive antenna technology for imaging applications, such as biological and bio-medical applications, non-destructive inspection of fabrics and plastics, analysis of hydration levels or detecting the presence of metallic components in samples, and detecting a variety of materials with unique spectral fingerprints in the terahertz frequency range, such as different types of explosives or several compounds used in the fabrication of medicines. Provides a comprehensive review of terahertz source and detector for imaging and sensing;Discusses photoconductive antenna technology for imaging and sensing;Presents modalities for improving the photoconductive dipole antenna performance for imaging and sensing;Explores applications in tomographic imaging, art conservation and the pharmaceutical and aerospace industries. Preface Contents About the Authors List of Figures List of Tables Chapter 1: Introduction 1.1 Introduction 1.2 Terahertz Electromagnetic Spectrum 1.3 Application of Terahertz Radiations 1.3.1 Material Characterization 1.3.2 Sensing and Imaging Security Screening of Letters, Envelopes, and Small Packages Security Screening of People (Body Scanner) 1.3.3 Next-Generation Communication 1.3.4 T-Ray Tomography 1.4 Overview of Continuous and Pulsed Terahertz Imaging Systems 1.4.1 THz Sources for Imaging Systems 1.4.2 Performance Comparison Between Continuous and Pulsed THz Imaging System 1.5 Terahertz Pulsed Imaging System for Detection of Hidden Explosives 1.5.1 Potential Challenges of THz Pulsed Imaging System 1.6 Related Work 1.7 Problem Formulation 1.8 Organization of Book 1.9 Summary References Chapter 2: Terahertz Imaging Modalities: State-of-the Art and Open Challenges 2.1 Introduction 2.2 Transmission-Type and Reflection-Type Terahertz Imaging 2.3 Terahertz Imaging Based on Conductivity 2.4 Classification of Terahertz Imaging with Diffraction Limit 2.4.1 Terahertz Imaging Below Diffraction Limit 2.4.2 Terahertz Time-of-Flight Imaging 2.5 Computed Tomography 2.5.1 Tomography with Pulse Terahertz Radiation 2.6 Special Case Imaging Applications 2.6.1 Imaging with Compressed Sensing 2.6.2 Spectroscopic Imaging 2.6.3 FMCW Radar Imaging 2.6.4 Near-Field Imaging 2.6.5 Far-Field Imaging 2.7 Summary References Chapter 3: Terahertz Antenna Technology for Imaging and Sensing Applications 3.1 Introduction 3.2 State-of-the-Art Terahertz Antennas Based on Integrated Circuits 3.2.1 Existing Technology Health Applications Military Applications Environmental Pollution Monitoring Application Technology in the Field of Entertainment Satellite Communication Application 3.2.2 Sources 3.2.3 Receiver 3.2.4 Antenna and Its Array Technology 3.3 Terahertz Antennas for Imaging Applications 3.4 Terahertz Antennas for Sensing Applications 3.5 Summary References Chapter 4: Small-Gap Photoconductive Dipole Antenna for Imaging and Sensing 4.1 Introduction 4.2 Related Work and Problem Formulation 4.3 Parametric Estimation of Photoconductive Dipole Antenna 4.3.1 Working Phenomenon of Small-Gap Photoconductive Dipole Antenna 4.3.2 Antenna Physical Parameter Estimation Technique Use of Thin LT-GaAs Superstrate Use of Silicon Hemispherical Lens 4.4 Simulation Model 4.4.1 Computation of Laser-to-Electrical Conversion Efficiency 4.4.2 Calculation of Impedance Matching Efficiency 4.4.3 Computation of Radiation Efficiency 4.5 Simulation Results and Discussions 4.6 Summary References Chapter 5: Analytical Framework of Small-Gap Photoconductive Dipole Antenna: An Equivalent Circuit Model 5.1 Introduction 5.2 Related Work and Problem Formulation 5.3 Circuit Modeling Using Numerical Equations 5.4 Radiated Power and Total Efficiency 5.5 Simulation Results and Discussions 5.6 Summary References Chapter 6: Directivity Enhancement of Terahertz Photoconductive Dipole Antenna: Approach of Frequency Selective Surface 6.1 Introduction 6.2 Related Work and Problem Formulation 6.3 Theory of Operation 6.3.1 Analysis Procedure of Frequency Selective Surface 6.3.2 Modeling of FSS Bandpass Structure 6.4 Design of FSS-PCA 6.5 Numerical Analysis and Simulation Results 6.5.1 Effect of Slot Size on Antenna Performance Parameters 6.5.2 Effect of FSS as Superstrate 6.6 Proposed Photoconductive Dipole Antenna with 4 × 4 FSS Bandpass Superstrate 6.7 Summary References Chapter 7: Highly Directive Lens-Less Photoconductive Dipole Antenna Array for Imaging Applications 7.1 Introduction 7.2 Related Work and Problem Formulation 7.3 Unit-Cell Antenna Modeling 7.4 Design of Photoconductive Antenna Array 7.5 Frequency Selective Surface for Photoconductive Antenna Array 7.5.1 Analysis of Unit-Cell Frequency Selective Surface 7.5.2 Estimation of Resonance Condition Using Ray Tracing 7.6 Numerical Analysis and Simulation Results 7.7 Summary References Chapter 8: Beam-Steering Characteristics of Highly Directive Photoconductive Dipole Phased Array Antenna 8.1 Introduction 8.2 Related Work and Problem Formulation 8.3 Design of Photoconductive Dipole Phased Array Antenna with FSS 8.4 Numerical Analysis and Simulation Results 8.5 Summary References Chapter 9: Terahertz Near-Field Imaging and Sensing 9.1 Introduction 9.2 State-of-the-Art Terahertz Near-Field Imaging 9.3 Terahertz Near-Field Measurements 9.4 Near-Fields of Various Subwavelength Holes 9.5 Kirchhoff Formalism for Near-Field Estimate 9.6 Summary References Chapter 10: Terahertz Technology for Biomedical Application 10.1 Introduction 10.2 Applications of Terahertz Imaging 10.3 Background for Medical Imaging Applications 10.4 Influence of Radiation on Biomolecules 10.5 Comparison of Different Medical Imaging Techniques 10.6 Terahertz Biosensor 10.7 Summary References Chapter 11: Terahertz Integrated Circuit Design 11.1 Introduction 11.2 Silicon Technology for Terahertz Integrated Circuit 11.3 Terahertz Sources and Detectors Based on Silicon Technologies 11.3.1 Terahertz Silicon-Based Sources 11.3.2 Terahertz Silicon Detectors 11.3.3 Terahertz Transceivers 11.4 Integrated Antenna Technology 11.4.1 State-of-the-Art Terahertz Integrated Arrays 11.4.2 Integrated Planar Antenna Arrays 11.4.3 Integrated Focal Plane Antenna Arrays 11.5 Planar Antenna Array for Near-Field Imaging 11.5.1 Near-Field Imaging System Design 11.5.2 Retina Design 11.6 Hybrid Electronic–Photonic Systems 11.7 Tomography Imaging Techniques 11.8 Summary References Index