Terahertz Antenna Technology for Imaging and Sensing Applications

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