W-band 항행 레이더용 전파흡수체에 관한 연구
|dc.description.abstract||Millimeter wave radars are employed in a wide range of commercial, military and scientific applications for remote sensing, safety, and measurements. But, radar systems suffer from two major problems such as false images and system-to-system interference. False echoes cause driving hazards. These problems can be eliminated through the use of an EM wave absorber. In this dissertation, the EM wave absorbers using Carbon black as a conductive material, TiO2 as a dielectric material, and Permalloy as a magnetic material with CPE were designed and fabricated for W-band navigation radars. First of all, the complex relative permittivity and permeability of three-type absorbing materials are calculated from the S-parameter. The optimum composition ratios of absorbing materials were determined from absorption ability of various composite. The EM wave absorption abilities at different thicknesses are simulated using material properties of the EM wave absorbers, and the EM wave absorbers were fabricated based on the simulated designs. The simulated and measured results agree very well. As a result, the sheet-type absorbers were developed to eliminate false image and system-to-system interference of navigation radars in W-band.||-|
|dc.description.tableofcontents||Contents i Nomenclature iii List of Tables iv List of Figures v Abstract x Abstract translated into korean xiii Chapter 1 INTRODUCTION 1 1.1 Dissertation Objective 3 1.2 Outline of Remaining Chapters 4 Chapter 2 NAVIGATION RADAR FUNDAMENTAL 6 2.1 History of Radar Development 6 2.2 Radar System Fundamentals 9 2.3 Millimeter Wave Radar 11 2.4 Contributions of EM Wave Absorber 15 Chapter 3 THEORY OF EM WAVE ABSORBER 17 3.1 History of EM Wave Absorber 17 3.2 Electromagnetic Theory 19 3.3 Loss mechanism 26 3.4 Classification of EM Wave Absorber 30 3.5 Application of EM Wave Absorber 33 Chapter 4 DESIGN OF EM WAVE ABSORBER 41 4.1 Introduction 41 4.2 Single-layer Absorber 43 4.3 Multi-layer absorber 47 Chapter 5 MATERIAL PROPERTIES 51 5.1 Introduction 51 5.2 Measurement Techniques of Material Properties 52 5.3 Manufacturing Process of Absorber 59 5.4 Measured Material Properties 62 5.5 SEM Photographs 75 Chapter 6 ABSORPTION ABILITY 79 6.1 Introduction 79 6.2 Measurement Techniques of Absorption Ability 80 6.3 Simulated Absorption Ability 85 6.4 Measured Absorption Ability 94 Chapter 7 CONCLUSIONS 108 References 111 Published papers concerned with this dissertation 116 Acknowledgement 122||-|
|dc.title||W-band 항행 레이더용 전파흡수체에 관한 연구||-|
|dc.title.alternative||A Study on the EM Wave Absorber for W-band Navigation Radars||-|
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