Wideband and UWB antennas for wireless applications. A comprehensive review

A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems

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

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

Gain enhancement of BiCMOS on-chip sub-THz antennas by mean of meta-cells

A MM-loaded sub-THz on-chip antenna with a narrow beamwidth, 9 dB gain and a simulated peak efficiency of 76% at the center frequency of 300 GHz is presented. By surrounding the antenna with a single MM-cell ring defined solely on the top metal of the back-end of line, an efficient suppression of the surface waves is obtained. The on-chip antenna has been designed using IHPs 130 nm SiGe BiCMOS technology with a 7-layer metallization stack, combined with the local backside etching process aimed to creating an air cavity which is then terminated by a reflective plane. By comparing the measured MM-loaded antenna performances to its non-MM-loaded counterpart, an enhanced integrity of the main lobe due to the MM-cells shielding effect can be observed. An excellent agreement between the simulated and measured performances has been found, which makes the MM-loaded antennas a valid alternative for the upcoming next-generation sub-THz transceivers

Through Wall Imaging Radar Antenna with a Focus on Opening New Research Avenues

This review paper is an effort to develop insight into the development in antennas for through wall imaging radar application. Review on literature on antennas for use in through wall imaging radar, fulfilling one or more requirements/specifications such as ultrawide bandwidth, stable and high gain, stable unidirectional radiation pattern, wide scanning angle, compactness ensuring portability and facilitating real-time efficient and simple imaging is presented. The review covers variants of Vivaldi, Bow tie, Horn, Spiral, Patch and Magneto-electric dipole antennas demonstrated as suitable antennas for the through wall imaging radar application. With an aim to open new research avenues for making better through wall imaging radar antenna, review on relevant compressive reflector antennas, surface integrated waveguide antennas, plasma antennas, metamaterial antennas and single frequency dynamically configurable meta-surface antennas are incorporated. The review paper brings out possibilities of designing an optimum through wall imaging radar antenna and prospects of future research on the antenna to improve radiation pattern and facilitate overall simple and efficient imaging by the through wall imaging radar

Silicon - polymer hybrid integrated microwave photonic devices for optical interconnects and electromagnetic wave detection

textThe accelerating increase in information traffic demands the expansion of optical access network systems that require high-performance optical and photonic components. In short-range communication links, optical interconnects have been widely accepted as a viable approach to solve the problems that copper based electrical interconnects have encountered in keeping up with the surge in the data rate demand over the last decades. Low cost, ease of fabrication, and integration capabilities of low optical-loss polymers make them attractive for integrated photonic applications to support futuristic data communication networks. In addition to passive wave-guiding components, electro-optic (EO) polymers consisting of a polymeric matrix doped with organic nonlinear chromophores have enabled wide-RF-bandwidth and low-power active photonic devices. Beside board level passive and active optical components, on-chip micro- or nano-photonic devices have been made possible by the hybrid integration of EO polymers onto the silicon platform. In recent years, silicon photonics have attracted a significant amount of attentions, because it offers compact device size and the potential of complementary metal–oxide–semiconductor (CMOS) compatible photonic integrated circuits. The combination of silicon photonics and EO polymers can enable miniaturized and high-performance hybrid integrated photonic devices, such as electro-optic modulators, optical interconnects, and microwave photonic sensors. Silicon photonic crystal waveguides (PCWs) exhibit slow-light effects which are beneficial for device miniaturization. Especially, EO polymer filled silicon slotted PCWs further reduce the device size and enhance the device performance by combining the best of these two systems. The potential applications of these silicon-polymer hybrid integrated devices include not only optical interconnects, but also optical sensing and microwave photonics. In this dissertation, the design, fabrication, and characterization of several types of silicon-polymer hybrid photonic devices will be presented, including EO polymer filled silicon PCW modulators for on-chip optical interconnects, antenna-coupled optical modulators for electromagnetic wave detections, and low-loss strip-to-slot PCW mode converters. In addition, some polymer-based devices and silicon-based photonic devices will also be presented, such as traveling wave electro-optic polymer modulators based on domain-inversion directional couplers, and silicon thermo-optic switches based on coupled photonic crystal microcavities. Furthermore, some microwave (or RF) components such as integrated broadband bowtie antennas for microwave photonic applications will be covered. Some on-going work or suggested future work will also be introduced, including in-device pyroelectric poling for EO polymer filled silicon slot PCWs, millimeter- or Terahertz-wave sensors based on EO polymer filled plasmonic slot waveguide, low-loss silicon-polymer hybrid slot photonic crystal waveguides fabricated by CMOS foundry, logic devices based on EO polymer microring resonators, and so on.Electrical and Computer Engineerin

Compact, Low-Profile, Bandwidth-Enhanced Substrate Integrated Waveguide Filtenna

© 2011 IEEE. In this letter, a compact, low-profile, bandwidth-enhanced, dual-cavity substrate integrated waveguide (SIW) filtenna is demonstrated. Two SIW cavities are stacked vertically on top of each other. A complementary split-ring resonator slot is etched in the top surface of the uppermost cavity, causing the top surface to act as a patch antenna. The operational impedance bandwidth is significantly enhanced by merging the three resonances that arise from this configuration. One is introduced by the patch, and the other two are inherently generated by the two cavities. A metallized coupling post is introduced from the ground plane through both cavities to the upper surface to excite the fundamental resonant mode of the patch, as well as to electromagnetically couple the two cavities. The optimized filtenna was fabricated by a standard printed circuit board technology and tested. It has a low profile λ 0 and a compact size 0.62λ 0×0.62λ0 at its center frequency, f0=2.95GHz. The measured results agree well with their simulated values. They demonstrate a 6.3% fractional bandwidth, a maximum realized gain of 6.73 dBi, a flat gain profile within its passband, and an excellent out-of-band selectivity

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

Analysis and design of antennas and radiometers for radio astronomy applications in microwave, Mm-wave, and THz Bands

Mención Internacional en el título de doctorWe are living in interesting times for astronomy science, since the birth of the radio astronomy field in the 20th century by Karl Jansky, the availability of new and better radio astronomy receivers is in increasing demand to push the human understanding of the universe. In this thesis, various components (antennas, baluns, antenna-arrays, and radiometers) are proposed for radio astronomy receivers. The proposed designs are belonging to three receiver topologies (direct detection, down-conversion, and up-conversion) that operate at different frequency bands from MHz up to a few of THz. Also, to demonstrate that the same proposed design is capable of working efficiently at different operating frequencies, multiple adjusted designs are presented for several practical radio astronomy and space applications. Firstly, a receiver based on the direct detection of the Electromagnetic (EM) radiation through a radio telescope working on cryogenic cooling conditions. In this part, the focus is on designing conical log-spiral antennas and baluns (balanced to unbalanced transformers) to be used as feeds for VLBI Global Observing System (VGOS) ground-based radio telescopes. The feeds cover the Ultrawideband (UWB) from 2 GHz to 14 GHz with Circular Polarization (CP) radiation and stable radiation patterns. After integration of the feeds to the radio telescope, the whole system operates with high aperture efficiency and high System Equivalent Flux Density (SEFD) over the whole required wide range. The fabrication, assembly, and measurements for single-element and four-elements array are provided for achieving the requirements for single CP and dual CP operation. Also, in the same first part, the proposed single-element feed (antenna + balun) is readjusted for being used for CryoRad spaceborne Earth observations. This feed has a single CP over low-frequency UWB from 400MHz to 2 GHz with low weight and physical size compared to standard horn feeds. The second part of the thesis is dedicated to a THz source to be used as a local oscillator for heterodyne radio astronomy THz receivers in which the down-conversion of the THz radiation to a lower frequency occurs. The source is based on an array of self-complementary bow-tie antennas and photomixers that lies on a dielectric lens. The source can be scaled easily to cover different UWB ranges, three ranges are analyzed from 200 GHz to 2 THz, 100 GHz to 1 THz, and 50 GHz to 0.5 THz. Additionally, in this part, a complete study for the effects of metal losses on such THz planar antennas is performed which are not well-investigated in literature yet, the physical explanations behind such effects are also provided. Although these proposed THz sources themselves can work at room temperature, the receiver probably still needs the cooling for the other receiver components (such as the mixer) to work efficiently at such high frequencies. This is the motivation for the third part of this thesis which presents a different type of radio astronomy receiver that is completely able to work without cooling. The third receiver is based on the nonlinear up-converting of the microwave radiation into the optical domain using Whispering Gallery Mode (WGM) resonators which can work at room temperature efficiently. For such advantage and since this concept is naturally narrow-band, it can be a proper candidate for Cosmic Microwave Background (CMB) spectroscopy and space applications. The system design and its performance are analyzed for Ku band at 12 GHz with proposing a novel microwave coupling scheme for enhancing the up-conversion photonic efficiency which is the main limitation for such upconversion systems. Likewise, several high gain 3D-printed Dielectric Resonator Antenna (DRA)s are proposed in both isolated and array configurations to have a direct coupling of the microwave radiation to the proposed scheme. Another practical application for such receiver is presented for CubeSat missions at the mm-wave band (183 GHz) for climate change forecasting. It is clear here that removing the cryogenic cooling conditions decreases satellite weight and cost, which in turn significantly increases its lifetime. Also, it is worth noting that besides the radio astronomy applications, the proposed receivers (and/or their antenna/components) can be used for many other applications. For example, the UWB antennas in the first part can be used as wideband scalable probes for EM compatibility testing or other wireless systems that require single or dual CP such as radar and military applications. This is because the solutions provide constant beam characteristics with good CP polarization purity and stable performance over the operating UWB. In the same way, the proposed THz source in the second part can be used in several THz applications such as very high-speed wireless communications, highresolution imaging for medical and security purposes. This is because of its key benefits as decade bandwidth, compact size, low noise, low power demand, high tunability, and the ability to work at room temperature. For the up-conversion scheme proposed in the third part, due to its high photonic efficiency, low noise level which enables it to work at room temperature, and its scalability from a few GHz up to several THz, it is suitable for low-cost and high sensitivity applications. Specifically, the ones that need to get rid of the hard cryogenic cooling conditions, or at least, relax them and allow the system to work efficiently at higher temperatures. For instance, portable mm-wave and THz systems for quality control, security, and biochemistry. Finally, in this part, the proposed DRA elements and arrays, due to their low cost, high gain, and low losses, can be used for sensing applications and 5G base station antennas.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Raed Shubair.- Secretario: Adrián Amor Martín.- Vocal: José Manuel Fernández Gonzále

Reconfigurable and Tunable Metamaterials: A Review of the Theory and Applications

Metamaterials are being applied to the development and construction of many new devices throughout the electromagnetic spectrum. Limitations posed by the metamaterial operational bandwidth and losses can be effectively mitigated through the incorporation of tunable elements into the metamaterial devices. There are a wide range of approaches that have been advanced in the literature for adding reconfiguration to metamaterial devices all the way from the RF through the optical regimes, but some techniques are useful only for certain wavelength bands. A range of tuning techniques span from active circuit elements introduced into the resonant conductive metamaterial geometries to constituent materials that change electromagnetic properties under specific environmental stimuli. This paper presents a survey of the development of reconfigurable and tunable metamaterial technology as well as of the applications where such capabilities are valuable