2008 Index IEEE Transactions on Control Systems Technology Vol. 16

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

2009 Index IEEE Antennas and Wireless Propagation Letters Vol. 8

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author\u27s name. The primary entry includes the coauthors\u27 names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, month, and inclusive pagination. The Subject Index contains entries describing the item under all appropriate subject headings, plus the first author\u27s name, the publication abbreviation, month, and year, and inclusive pages. Note that the item title is found only under the primary entry in the Author Index

Comparison of Near-Field Millimeter Wave Probes for Detecting Corrosion Pit under Paint

Corrosion pitting defection is a critical issue in the maintenance of aircraft. Near-field microwave nondestructive techniques have been successfully used for defection of corrosion under paint. In this paper a comparison between several different millimeter wave probes is made for the detection and evaluation of corrosion precursor pitting under paint at Ka-band and V-band. Since the pittings investigated here are very small in size, spatial resolution and sensitivity of the probes are critical issues. If is shown that modified open-ended rectangular probes namely, tapered waveguide and dielectric slab-loaded waveguide probes provide high resolution and sensitivity for the detection and evaluation of very small pittings under paint

High Resolution Near Field Microwave Imaging using Loaded Circular Aperture Probe

Circular aperture probes have been successfully used for high-resolution near-field microwave imaging. It has been established that circular aperture probes could conceivably provide higher image fidelity compared to rectangular aperture probes used conventionally for near-field imaging. In this paper, it is proposed to further enhance the near-field imaging resolution and sensitivity by loading the circular aperture with a resonant iris. The proposed probe herein operates in the X-band frequency range and exhibits very localized near-field distribution at the opening of the iris. Consequently, its imaging resolution and sensitivity are enhanced compared to the conventional aperture probes operating over the same frequency band. The imaging capability of the proposed probe is analyzed using 3D electromagnetic simulation, and its performance is validated experimentally. The efficacy of the proposed probe for high-resolution imaging is demonstrated by practical imaging dielectric and metallic samples. Furthermore, the obtained images using the proposed probe are compared to those acquired using conventional circular and rectangular aperture probes. It will be demonstrated that the proposed probe provides higher sensitivity and resolution compared to the conventional aperture probes

Design of a mm-wave Planar CPW-fed Tapered Dielectric Rod Antenna

The demand for high data rate transfers in short range areas have been increasing significantly. Millimeter wave communication systems can fulfill the requirements for such applications due to the availability of wide bandwidths at these frequencies. Particularly, 60 GHz frequency band is more appropriate among other mm-wave bands because of the oxygen energy absorption resonance at this frequency. Millimeter wave antennas are one of the desired components in short range wireless communications. High gain and broadband antennas are required for this purpose. In this study, a fully planar 60 GHz antenna is introduced. Tapered dielectric rod antenna is chosen to achieve high radiation efficiency. The antenna is designed on two common substrates with high permittivity: alumina (Al2O3) and high resistive Silicon. Both substrates are very low loss and many designs for front-end components are developed on these substrates due to their high permittivity. In other words, the proposed antenna can be integrated with the front-end platform in the same substrate. In addition, the antenna feeding is the CPW line which makes it a convenient solution for integration of the antenna with RF front-ends such as MMICs or MEMS circuits in this range of frequency

Detection of Surface Cracks in Metals using Microwave and Millimeter-Wave Nondestructive Testing Techniques-A Review

Integrity Assessment of Metallic Structures Requires Inspection Tools Capable of Detecting and Evaluating Cracks Reliably. to This End, Many Microwave and Millimeter-Wave Nondestructive Testing and Evaluation (NDT&E) Methods Have Been Developed and Applied Successfully in the Past. Detection of Fatigue Cracks with Widths Less Than 5 Μ M using Noncontact Microwave-Based Inspection Methods Was Demonstrated in the 1970s. Since their Introduction, These Methods Have Evolved Considerably Toward Enhancing the Detection Sensitivity and Resolution. Undertaking Key Application Challenges Has Attracted Considerable Attention in the Past Three Decades and Led to the Development of the Near-Field Techniques for Crack Detection. to Address a Need that Cannot Be Fulfilled by Other NDT&E Modalities, Innovative Noncontact Microwave and Millimeter-Wave NDT&E Methods Were Devised Recently to Detect Cracks of Arbitrary Orientations under Thick Dielectric Structures. While the Reported Methods Share the Same Underlying Physical Principles, They Vary Considerably in Terms of the Devised Probes/sensors and the Application Procedure. Consequently, their Sensitivity and Resolution as Well as their Limitations Vary. This Article Reviews the Various Crack Detection Methods Developed To-Date and Compares Them in Terms of Common Performance Metrics. This Comprehensive Review is Augmented with Experimental Comparisons and Benchmarking Aimed to Benefit NDT&E Practitioners and Researchers Alike

The properties of Terahertz Wave Propagation in Parallel-Plate Waveguides

테라헤르츠(이하, THz) 파는 전자기파 스펙트럼 영역에서 마이크로웨이브 영역과 적외선 영역의 사이로, 일반적으로 0.1~10THz (파장:3mm~30μm)에 해당하는 파를 말하며, 적외선이 가지는 직진성과 마이크로웨이브가 가지는 투과성을 동시에 가지는 독특한 특성을 가지는 영역대의 전자기파이다. 따라서, 비금속성을 띄는 대부분의 물질의(옷, 나무, 플라스틱, 종이 등) 투과가 가능하여 이와 같은 재질로 내부에 숨겨져 있는 물질의 확인이 가능하며(이미징), 인체와 같은 바이오 물질의 경우, 기존에 사용되어 오던 X-ray에(106THz=4.13keV) 비하여 에너지가(1THz=4.13meV) 현저히 낮기 때문에 물질의 원자나 분자를 이온화 시키지 않는 비파괴 특성을 가진다. 또한, 많은 물질의 분자들이 THz 영역에서 공진 특성을 가지고 있어 물질의 연구(분광학)에도 많이 사용되고 있다. 게다가, 앞으로 기존의 무선 통신 및 정보 처리 등에 있어 더 넓은 대역폭과 더 빠른 속도를 필요로 함에 따라 THz 파가 사용되게 될 것이다. 이렇듯, 앞으로 그 응용은 기존의 다른 영역의 기술과 결합하여 계속해서 확대 되게 될 것이다. 최근, THz 파의 단일 횡전자계(TEM) 모드의 전파가 가능한 평행금속판도파로의 특성을 이용하여, 분광학(spectroscopy), 포토닉 도파로(photonic waveguide), 이미징, 필터, 센서 등의 여러 분야에서 활발한 응용이 진행되고 있다. 이 중에서 THz 파의 다양한 응용 및 집적 회로의 구현 등, 모든 시스템에 기본적으로 필요한 수동 소자, 즉 여러 기능의 필터 개발은 반드시 필요하다. 이에 본 저자는 스펙트럼 영역에서 강한 차단 영역, 즉 밴드 갭의 형성이 가능한 포토닉 결정 구조를 평행금속판도파로 구조와 결합하여 다양한 기초 연구 및 그 응용 연구를 실시하였다. 먼저, (Chapter II) 평행금속판도파로의 기본 단일, 다중 모드 전파 특성에 관한 기초 연구를 이론 및 실험을 통하여 실시하였으며, (Chapter III) 이 중, 저주파 영역을 차단하는 스펙트럼 전파 특성을 가진 TE1 모드를 이용하여 THz 고주파 대역 통과 필터를 구현하였다. 그리고, (Chapter IV) 파장 이하의 좁은 공간에 THz 파를 집속, 전파가 가능한 평행금속판도파로의 특성을 이용하여 THz 파가 평행금속판도파로로부터 빠져 나오는 출구 근처에(THz 표면파) 슬릿 배열의 포토닉 결정 구조를 위치시켜, THz 표면파와 포토닉 결정 구조 간의 강한 Bragg 반사 현상과 이에 대한 각 슬릿의 반사 계수를 성공적으로 측정하였다. (Chapter V) 그리고, 기존까지 자유 공간을 전파하는 THz 파를 파장 이하의 평행금속판도파로 갭 사이로 결합시키기 위해 준광학 기법인 실리콘 렌즈가 사용되었다. 하지만, 이는 실리콘 렌즈의 높은 굴절률(n=3.417)에 따른 반사 손실이 두 실리콘 렌즈의 의해 약 50%가 발생하며 또한, 실리콘 내부 전반사로 인하여 시간 영역에서 긴 측정을 불가능하게 만드는 다중 반사 신호가 측정된다. 따라서, 실리콘 렌즈를 경사각 3o를 가지는 경사진 도파로 구조로 대체하여 기존 실리콘 렌즈의 사용에 비해 약 2배 이상의 결합 효율 향상 및 내부 전반사를 제거하였다. (Chapter VI) 이 장에서는 Chapter V에서 연구 된 포토닉 결정 구조, 즉 슬릿 배열을 평행금속판도파로 내의 갭 중앙에 위치시켜, 집속된 THz 파와 슬릿 배열 간의 여러 강한 밴드 갭을 구현하였고, 발생한 여러 밴드 갭에 대한 그 형성 메카니즘을 C언어를 이용하여 직접 구현한 Finite-Difference Time-Domain 시뮬레이션을 이용하여 완벽히 분석하였다. (Chapter VII) 그리고, photonic band anti-crossing 모델을 이용하여 앞서 형성된 밴드 갭 중, 평행금속판과 슬릿 사이의 간격에 따라 밴드 갭의 위치가 변화는 현상을 다른 접근에서 분석하였으며, (Chapter VIII) Chapter VI에서 형성된 밴드 갭 내에 결함 구조의 슬릿 배열을 이용, 강한 결함 모드를 발생시켜 이에 대한 연구를 실시하였다. (Chapter IX) 그리고, 앞서 분석한 밴드 갭 형성 메카니즘의 이해를 바탕으로, 저주파, 특정 주파수 대역 통과 필터 및 특정 주파수 가변 차단 필터를 개발하였고, 이를 미량의 가스 검출이 가능한 센서로의 적용을 실시하였다. (Chapter X) Chatper VI에서 연구된 슬릿 배열과 유사한 홈(groove) 배열을 평행금속판도파로의 갭 중앙이 아닌 한쪽 금속판 내에 구조화하여 앞서 슬릿 배열의 경우보다 더 많은 여러 밴드 갭의 구현 및 그 형성 메카니즘을 분석하였다. (Chapter XI) 그리고, 앞서 Chapter X에서의 여러 밴드 갭을 이용하여 여러 필터 및 미량의 가스 및 유동 액체 센서로의 응용을 실시하였다. (Chapter XII) 이 장에서는 새로운 형태의 평행금속판도파로를 제안한다. 기존의 두껍고 평평한 평행금속판 구조에서 30 μm의 얇은 금속판에 슬릿 배열을 가공하여 도파로의 내외부가 슬릿을 통하여 연결이 되도록 하였다. 따라서, 도파로 내부를 전파해 나가던 THz 파가 전자기파의 회절 현상으로 인하여 공기 슬릿 배열을 통하여 도파로 내에서 외부로 빠져나가게 되는 반면, 도파로의 공기 갭의 두 배에 해당하는 길이의 파장에서 강한 투과 공진 현상이 일어나게 되어, 마치 특정 밴드 패스 필터의 특성을 가지게 되었다. 이는 횡전자계 모드를 이용한 저주파 차단은 처음이며, 공기 갭의 조절에 의하여 특정 밴드의 주파수 가변이 가능하다. 또한, 외부로 드러나는 특이한 구조로 인하여 앞으로 다양한 응용의 가능성이 기대된다.Chapter I Introduction 1 1.1 Metal parallel-plate waveguides 1 1.2 Photonic crystals 2 1.3 Outline of Thesis 3 1.4 Broadband THz setup 5 Chapter II THz propagation through PPWGs 7 2.1 Waveguide Specimen 7 2.2 Fundamental theory of PPWG 9 2.2.1 General Wave Characteristics in a PPWG structure 10 2.2.2 TMm mode (TM0 = TEM) 11 2.2.3 TE modes 12 2.2.4 Cutoff frequencies for TM and TE modes 13 2.2.5 Waveguide Group velocity and Phase velocity 15 2.2.6 Attenuation in Waveguide 18 2.3 Single TEM and TE1 mode 19 2.3.1 Experimental Results : Reference and single TEM mode 21 2.3.2 Experimental Results : TE mode 23 2.4 Multi-TM and TE modes 25 2.4.1 Experimental Results : multi-TM modes 26 2.4.2 Experimental Results : multi-TE modes 28 2.5 Mode analysis 30 2.5.1 Spectrocronography 30 2.5.2 Fitting 32 Chapter III THz Filter Using the TE1 Mode of PPWG 34 3.1 Experimental setup 35 3.2 Experiment results : TM modes 36 3.3 Experiment results : TE1 mode 38 3.4 Analysis : High pass filter using TE1 mode 40 Chapter IV Bragg resonance of THz surface waves in photonic crystals 44 4.1 THz surface wave propagation on rectangular aperture arrays 45 4.1.1 Analysis of the propagated THz waves through samples 46 4.1.2 Analysis of the resonance phenomenon 48 4.2 Bragg reflection of THz surface wave propagation on slit aperture arrays 49 4.2.1 Measurements and analysis : Numerical fitting 50 4.2.2 Measurements and analysis : Interference phenomenon 52 4.2.3 Theoretical calculations of the reflection coefficient 54 Chapter V Improvement of THz coupling using a tapered parallel-plate waveguide 56 5.1 Experiment setup : Tapered waveguide specimen 57 5.2 Experiment results : One-sided TPPWG with the different angles 58 5.3 FDTD simulations and measurements : Round and non-round TPPWG 59 5.4 FDTD simulations : Output tapered structure for two-sided TPPWG 62 5.5 Measurements and analysis : Two-sided TPPWG 63 Chapter VI THz band gap properties by using metal slits in TPPWG 65 6.1 Experiment setup 66 6.2 Experiment results 67 6.3 FDTD simulations : A1, A2 - Bragg stop band 70 6.4 FDTD simulations : B, C – non-Bragg stop band 72 6.5 FDTD simulations : 3-D THz power transmission 74 Chapter VII Photonic band anti-crossing in a coupled system of a THz plasmonic crystal film and a metal air-gap waveguide 75 7.1 Experiment setup 76 7.2 FDTD simulations and experiment results 76 7.3 Analysis : Anti-crossing model 78 Chapter VIII Properties of defected one-dimensional THz plasmonic crystal films in a metal air-gap waveguide 81 8.1 Experiment setup 82 8.2 FDTD simulations : Defect modes 82 8.3 FDTD simulations and experimental results 83 Chapter IX Application for THz filters and Sensing based on band gaps properties by using metal slits in TPPWG 87 9.1 Experimental setup : Notch Filter 88 9.2 Experimental results : Notch Filter 89 9.3 FDTD simulations : Notch Filter 91 9.4 FDTD simulations : Notch Filter Sensor 93 9.5 FDTD simulations : Low-Pass Filter 95 9.6 Experimental results : Low-Pass Filter 97 Chapter X THz band gaps induced by metal grooves inside TPPWG 99 10.1 Experiment setup 100 10.2 Experiment results 101 10.3 FDTD simulations : Multiple Grooves vs Single Groove 103 10.4 FDTD simulations : Band gaps A~C and I~IV 104 Chapter XI Application for THz filters and Sensing based on band gaps properties by using metal grooves in TPPWG 109 11.1 Experimental setup : Notch filter 110 11.2 Experimental results : Notch filter 112 11.3 FDTD simulations : Tunable Notch filter 116 11.4 Application for tunable Notch filter using Piezo-actuator 117 11.5 FDTD simulations : Application for THz microfluidic sensor 118 11.6 FDTD simulations : Low-Pass Filter and Band-pass filter 119 11.7 Experimental results : Low-Pass Filter and Band-pass filter 121 Chapter XII Resonant transmission through slit arrays patterned parallel-plate waveguide 122 12.1 Experimental setup : Photonic PPWG 124 12.2 Experimental results and FDTD simulation : Photonic PPWG 125 12.3 FDTD simulations : Single slit and multiple slits 127 12.4 FDTD simulations : Misaligned photonic PPWG 130 12.5 FDTD simulations : Photonic PPWG 131 Chapter XIII Conclusion 132 Reference 13

Method and Apparatus for Nondestructive Sample Inspection

An apparatus for inspecting a sample for defects includes a signal generator for generating a signal and a device for splitting the signal into two separate signals which have substantially equal phase and magnitude. A sensor radiates the two signals on the sample and receives the two signals reflected from the sample. A device is provided for determining a difference between the two signals reflected from the sample without unwanted influence of variations of distance between the sensor and sample, and reflections from nearby sample edges and boundaries. A defect is determined to exist when a difference is found between the two reflected signals

Millimeter wave transmission systems and related devices

A survey was made of the state-of-the-art in millimeter (20 GHz to 300 GHz) wave transmission systems and related devices. The survey includes summaries of analytical studies and theoretical results that were obtained for various transmission line structures. This material was supplemented by further analysis where appropriate. The transmission line structures are evaluated in terms of electrical performance, ease of manufacture, usefulness for building other devices and compatibility with solid state devices. Descriptions of waveguide transmission lines which have commonly been used in the microwave frequency range are provided along with special attention given to the problems that these guides face when their use is extended into the millimeter wave range. Also, guides which have been introduced specifically to satisfy the requirements of millimeter wave transmission are discussed in detail