A 1 x 8 Linear Ultra-Wideband Phased Array With Connected Dipoles and Hyperbolic Microstrip Baluns

A 1×8 linear single polarized ultra-wideband connected dipole phased array with wide angle scan range is proposed. The dipoles in the array are connected with each other in E-plane to improve the impedance matching on the low end of the frequency band. The frequency band and the scan range in E-plane is 2~9 GHz for broadside radiation, 2~8 GHz for 30° scan, 2~7 GHz for 45° scan, and 2~6.5 GHz for 60° scan. The VSWR is better than 2.0 across the frequency band from 2 to 9 GHz for broadside radiation and the cross-polarization level is below -10 dB. A hyperbolic microstrip balun is used as an impedance transformer to connect the 50 Ω SMA connector to a 150 Ω broadband dipole in an array. The structure of this antenna is totally planar and low profile, thus it is made easy to integrate with the PCB boards. To eliminate the surface wave blindness, no other dielectric layer is used in the array. The proposed balun supports common mode (CM) current and the radiation of this CM current cancels the radiation of the dipole in some frequency for a certain scan angle, this results in feed blindness. Adding H-plane PEC walls decreases the feed blindness frequency in the design

Advances in composite right/left-handed transmission line components, antennas and systems

Résumé Les Métamatériaux (MTMs) électromagnétiques sont des matériaux artificiels qui présentent des propriétés remarquables non disponibles dans les substances naturelles. De récents travaux de recherche et de développement ont permis de démontrer des applications optiques et micro-ondes des MTMs, telles que des lentilles à super-résolution, des dispositifs d'invisibilité, de nouveaux filtres passe-bande, des coupleurs améliorés, des résonateurs et des antennes à ondes de fuite avec de nouvelles propriétés et performances. Avec la capacité à manipuler les ondes électromagnétiques se propageant par l'intermédiaire de leur support, les MTMs électromagnétiques pourraient devenir une clé importante des dispositifs et systèmes optiques, et micro-ondes de l'avenir.Cette thèse présente les dernières avancées des MTMs micro-ondes basés sur le concept des Lignes de Transmission Composites à Main Gauche/Droite (Composite Right/Left-Handed Transmission Line - CRLH TL). Les CRLH TLs sont des structures non-résonantes, constituées de la répétition périodique de série de condensateurs et d'inductances shunt très petits par rapport à la longueur d'onde guidée, qui ont une large bande et de faibles pertes pour les applications micro-ondes. De plus, les CRLH TLs planaires permettent une fabrication à faibles coûts en utilisant la technologie des circuits imprimés et un niveau élevé d'intégration avec les autres composants et systèmes. Ce travail constitue une contribution au développement de nouveaux composants, antennes et systèmes CRLH TL dans trois des classes d'applications spécifiques: onde guidée en régime harmonique, onde guidée en régime d'impulsionnel et onde rayonnée. Dans la première classe, un filtre passe-bande à large bande, un diviseur de puissance en série et des coupleurs à lignes couplées sont élaborés et vérifiés expérimentalement. La deuxième classe comprend un différentiateur et un émetteur à modulation par position d'impulsion. Dans la troisième classe, deux nouveaux concepts de recyclage de puissance améliorant systématiquement l'efficacité de rayonnement des antennes à ondes de fuite (Leaky-Wave Antenna - LWA) sont présentés, numériquement vérifiés par simulation électomagnétique et démontrés expérimentalement. Application de l'onde guidée en régime harmonique Le condensateur interdigital, généralement utilisé dans CRLH TLs, souffre d'une résonance transversale aux fréquences élevées à cause des courants en boucle formés entre ses doigts entrelacés. Cette résonance limite la bande passante des CRLH TLs. Pour cette raison, une nouvelle architecture de la CRLH TL basée sur le concept Métal-Isolant-Métal (MIM) a été proposée, caractérisée, démontrant sa capacité à supprimer complètement cette résonance transversale. La topologie MIM a les avantages d'être symétrique et de petite taille, tout en permettant d'exploiter pleinement la bande passante de la structure.----------Abstract Electromagnetic metamaterials (MTMs) are engineered artificial materials that exhibit unusual properties not available in natural materials. Recent research and development have shown promising optical and microwave applications of MTMs such as super-resolution lenses, cloaking devices, bandpass filter, enhanced couplers, resonators, and leaky-wave antennas with new properties and performance, to name a few. With the ability to manipulate electromagnetic waves propagating through its medium, electromagnetic MTMs are believed to hold an important key to many future optical and microwave devices and systems. This dissertation presents the most recent advances in microwave MTMs based on the Composite Right/Left-Handed (CRLH) transmission line (TL) concept. The CRLH TL based MTMs are non-resonant structures which are constituted of periodic repetition of series capacitors and shunt inductors with a unit cell's size much smaller than the guided wavelength and have favorable broadband and low-loss properties for microwave applications. In addition, planar CRLH TL-based MTMs permit a low-cost fabrication using printed circuit board (PCB) technology and a high level of integration with other microwave components and systems. This work contributes to the development of novel CRLH TL components, antennas and systems in three specific classes of application: harmonic regime guided-wave, impulse regime guided-wave and radiated-wave. In the first class, a wideband bandpass filter, an infinite wavelength series power divider and enhanced coupled-line coupler are developed and verified experimentally. The second class consists of a time differentiator component and a pulse position modulation transmitter system. In the third class, two novel power-recycling concepts to systematically enhance the radiation efficiency of Leaky-Wave Antennas (LWAs) are presented, verified numerically using electromagnetic simulation and demonstrated experimentally. Harmonic regime guided-wave application The interdigital capacitor, generally utilized in CRLH TLs, suffers a transverse resonance at high frequencies due to loop currents forming between adjacent interdigitated fingers. This resonance limits the operating bandwidth of CRLH TL based MTMs. For this reason, an alternative CRLH TL architecture based on Metal-Insulator-Metal (MIM) capacitors was proposed, characterized, and demonstrated to completely suppress the transverse resonance. The MIM based CRLH TL topology has advantages of symmetric design and small size while allows full operating bandwidth. Based on the new architecture, a bandpass filter with tapered coupled resonators was designed and the achieved ultra-wide bandwidth confirms its operation. In addition, an infinite wavelength series power divider using the same MIM based CRLH TL architecture in a stripline configuration was proposed and fabricated

Passive Planar Microwave Devices

The aim of this book is to highlight some recent advances in microwave planar devices. The development of planar technologies still generates great interest because of their many applications in fields as diverse as wireless communications, medical instrumentation, remote sensing, etc. In this book, particular interest has been focused on an electronically controllable phase shifter, wireless sensing, a multiband textile antenna, a MIMO antenna in microstrip technology, a miniaturized spoof plasmonic antipodal Vivaldi antenna, a dual-band balanced bandpass filter, glide-symmetric structures, a transparent multiband antenna for vehicle communications, a multilayer bandpass filter with high selectivity, microwave planar cutoff probes, and a wideband transition from microstrip to ridge empty substrate integrated waveguide

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Microwave periodic structures based on MicroElectroMechanical Systems (MEMS) and micromachining techniques

As a result of the ever growing number of functionalities and standards to be supported by communication systems, as well as the constant development of radar and imaging technologies, a key research area in the field of microwaves and millimeter waves is the achievement of reconfigurability capabilities. In recent years, the progress of MicroElectroMechanical Systems (MEMS) fabrication techniques has allowed radically challenging the performances of reconfigurable devices based on established technologies such as controllable ferrite material, semiconductor pin diodes or FET transistors. Consequently, there is presently significant effort to apply MEMS technology to the microwave field; in the case of high-cost applications (e.g. radars, satellites), the main reason is the state-of-the-art performances that MEMS technology can offer; namely, low losses, high linearity, large bandwidth. In the case of mass market (e.g.: mobile phone, GPS receiver), it is rather pushed by the increasing demand for the integration of numerous microwave functionalities into a monolithic, small, low-power consuming and low-cost device. In this context, the objective of this thesis is to contribute to the development of new periodic or cascadable microwave devices reconfigurable by means of MEMS. Indeed, numerous microwave devices take advantage of the particular propagation properties of a wave in periodic structures to achieve given functionalities (e.g. phase shifters, frequency selective surfaces, periodic antennas, antenna arrays and reflectarrays, metamaterials). For this purpose, analysis and design methods were developed based on the theory of waves propagating in periodic structures to help in dealing with different kinds of periodic or cascadable MEMS structures in an integrated approach. The method comprises the following main steps: the setup of efficient full-wave simulations of MEMS blocks, the derivation of physical and accurate circuit models, and the development of hybrid full-wave-circuit model design methods based on periodic structure modeling. It is noticeable that several theoretical developments presented are not restricted to micromachined and MEMS devices, but could be of use for many other microwave designs. Three main classes of devices have been studied and designed to illustrate the versatility of the approach, as well as the various potentialities of MEMS in microwave applications. The first structure addressed is an existing microwave MEMS structure, the distributed MEMS transmission line (DMTL), for which design methods based on the periodic structure modeling were developed. Analog and digital devices were fabricated, showing excellent agreement with the circuit modeled results. We also introduce and analyze a new topology for the reduction of the mismatch in multi-bit DMTLs. The results presented next consist mainly in theoretical developments on the metamaterial composite right/left handed transmission line (CRLH-TL) structure, carried out to overcome the limitations of existing models, which were shown to be inappropriate in the case of MEMS CRLH-TL implementations. Fixed micromachined devices were successfully designed based on the new theory, which also allowed the demonstration of the possibility to design especially low/high impedance CRLH-TLs. Next, MEMS implementations of variable CRLH-TLs are presented. Analog and digital devices were designed, and excellent agreements between full-wave simulations and circuit models are obtained in both cases. For fabrication reasons, only the analog device could be measured to exhibit the expected performances. This constitutes –to the author's knowledge– the first implementation of a MEMS-reconfigurable metamaterial structure. The last device studied is a MEMS-reconfigurable reflectarray cell. A comprehensive assessment of the numerous requirements for such a cell with regard to the functioning of a reconfigurable reflectarray is first presented, as well as detailed discussions on the rigorous simulation and measurement of the device. A monolithic MEMS reflectarray cell was then designed based on these considerations, and exhibits excellent performances in comparison with other reconfigurable reflectarray cells based on MEMS and other technologies

13th Annual Review of Progress in Applied Computational Electromagnetics at the Naval Postgraduate School, Monterey, CA, March 17-21, 1997, Conference Proceedings Volumes I & II

Includes Volumes 1 &

Aeronautical Engineering: A continuing bibliography with indexes

This bibliography lists 512 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1982