A Review: Substrate Integrated Waveguide Antennas and Arrays

This study aims to provide an overview and deployment of Substrate-Integrated Waveguide (SIW) based antenna and arrays, with different configurations, feeding mechanisms, and performances. Their performance improvement methods, including bandwidth enhancement, size reduction, and gain improvement are also discussed based on available literature. SIW technology, which acts as a bridge between planar and non-planar technology, is a very favorable candidate for the development of components operating at microwave and millimeter wave band. Due to this, SIW antennas and array take the advantages of both classical metallic waveguide, which includes high gain, high power capacity, low cross polarization, and high selectivity, and that of planar antennas which comprises low profile, light weight, low fabrication cost, conformability to planar or bent surfaces, and easy integration with planar circuits

A review on improved design techniques for high performance planar waveguide slot arrays

Planar waveguide slot arrays (WSAs) have been used since 1940 and are currently used as performing antennas for high frequencies, especially in applications such as communication and RADAR systems. We present in this work a review of the most typical waveguide slot array configurations proposed in the literature, describing their main limitations and drawbacks along with possible effective countermeasures. Our attention has been focused mainly on the improved available design techniques to obtain high performance WSAs. In particular, the addressed topics have been reported in the following. Partially filled WSAs, or WSAs covered with single or multilayer dielectric slabs, are discussed. The most prominent second-order effects in the planar array feeding network are introduced and accurately modeled. The attention is focused on the T-junction feeding the array, on the effect of interaction between each slot coupler of the feeding network and the radiating slots nearest to this coupler, and on the waveguide bends. All these effects can critically increase the first sidelobes if compared to the ideal case, causing a sensible worsening in the performance of the arra

Technologies for Near-Field Focused Microwave Antennas

This paper provides a review spanning different technologies used to implement near-field focused antennas at the microwave frequency band up to a few tens of GHz: arrays of microstrip patches and printed dipoles, arrays of dielectric resonator antennas, reflectarrays, transmitarrays, Fresnel zone plate lenses, leaky-wave antennas, and waveguide arrays

New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits

Research interest: In recent years we have seen the emergence of commercial applications at high frequencies, such as the top part of the microwave band and the millimeter and sub-millimeter bands, and it is expected a big increase in the coming years. This growing demand requires a rapid development of low-cost technology with good performance at these frequencies, where common technologies, such as microstrip and standard waveguides, have some shortcomings. In particular, existing solutions for high-gain planar scanning antennas at these frequencies su er from the disadvantages of these technologies giving rise to high-cost products not suitable for high volume production. Objectives: The main objective of this thesis is to study the feasibility of a new proposal to improve existing solutions to date for low-cost high-gain planar scanning antennas at high frequencies. This overall objective has resulted in another central objective of this thesis, which is the research of new quasi-TEM waveguides that are more appropriate than current technologies for the realization of circuits and components at these frequency bands. These guided solutions make use of periodic or arti cial surfaces in order to con- ne and channel the elds within these waveguides. Methodology: The work follows a logical sequence of speci c tasks aimed at achieving the main objective of this thesis. Chapter 2 presents the proposed guiding solution and shows its performance numerical and experimentally. The optimized design of high-gain antennas based on waveguide slot arrays requires the development of e cient ad-hoc codes. The implementation and validation of this code is presented in Chapter 3, where a new method for the analysis of corrugated surfaces is proposed, and in Chapter 4, which extends this code to the analysis of waveguide slot arrays. The process design and optimization of a two-dimensional array is described in Chapter 5, where a preliminary experimental validation is also described. Moreover, the proposed guiding solution has inspired the development of a new guiding technology of wider bandwidth and more versatile for the realization of circuits and components at high frequencies. Chapter 6 presents the contributions to the study of this technology and its application to the design of circuits.Alfonso Alós, E. (2011). New quasi-TEM waveguides using artificial surfaces and their application to antennas and circuits [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11073Palanci

Performance of a New Design Based on Substrate-Integrated Waveguide Slotted Antenna Arrays for Dual-Band Applications (Ku / K)

This paper introduces and discusses the study of a new concept for SIW array antenna development. This conducted development is based on three designs, two of them related to 1x2 arrays fed by SIW line, combined with SIW inset line, and the last designed for 2X2 array antenna feed by SIW inset line. All these structures are designed to give dual-band at (Ku - K) bands with enhanced gain and bandwidth. The new 2x2 array antenna has a high gain, and it consists of four SIW cavities staggered patches with a 90° phase shift, which are fed using microstrip line shielded by SIW vias. The designs were conducted using full-wave simulator ANSYS HFSS - the frequency domain solver. The 2x2 array antenna gives a return loss about (-20 dB), a high gain of 9.05 dB, and two bandwidth equals 210 MHz and 1310 MHz respectively at both of the operating bands. To validate the simulated results the simulation was conducted again using the time-domain solver of the CST Microwave Studio (MWS) full-wave simulator. Simulation results obtained from the two software having different solvers were in good agreement in the results

High-Efficiency Ka-Band Circularly Polarized Radial-Line Slot Array Antenna on a Bed of Nails

[EN] Radial-line slot-array antennas (RLSAs) provide an extremely simple solution to achieve high-gain circularly polarized radiation patterns without the need for complicated feeding networks or polarizers. The dielectric-filled radial waveguide, however, drastically reduces the efficiency that is potentially achievable by RLSA antennas at millimeter waveband. In this article, a novel architecture for an all-metal RLSA is proposed by replacing the dielectric material with a regular bed of metallic nails, thus maintaining the required slow wave characteristic within the radial waveguide. The slot array is efficiently optimized by using an ad hoc method-of-moments solver, based on the definition of an equivalent problem in the waveguide region. This accurate optimization process, along with the all-metal nature of the antenna, allows to reach a measured peak total efficiency above 80% at 30 GHz. The fabricated prototype consists of two pieces: the bottom waveguide with the bed of nails and the top slotted plate, which are easily assembled by means of a few screws. Experimental results report a peak gain of 35.0 dBi for a radiation efficiency of 94%, and a wideband matching performance with a very pure axial ratio, below 0.6 dB.This work was supported by MCIN/AEI/10.13039/501100011033 under Grant PID2019-107688RB-C22.Herranz Herruzo, JI.; Valero-Nogueira, A.; Ferrando-Rocher, M.; Bernardo-Clemente, B. (2022). High-Efficiency Ka-Band Circularly Polarized Radial-Line Slot Array Antenna on a Bed of Nails. IEEE Transactions on Antennas and Propagation. 70(5):3343-3353. https://doi.org/10.1109/TAP.2021.31373763343335370

Rectangular waveguide narrow-wall longitudinal-aperture antenna arrays for high-power applications

This work deals with the design and bench test of rectangular waveguide narrow-wall longitudinal-aperture antenna arrays for high power applications. The best narrow-wall longitudinal-aperture array designs in the work are called the double-narrow-wall-slot-HPB-array and the double-split-waveguide-HPB-array. The double-narrow-wall-slot-HPB-array (double-split-waveguide-HPB-array) consists of two identical narrow-wall-slot-HPB-arrays (split-waveguide-HPB-arrays) with a common broad wall. All elements of the split-waveguide-HPB-array are identical and are called H-plane-bend-radiators (HPB-radiators). An HPB-radiator is an H-plane bend terminating in a radiating aperture with the narrow dimension of the waveguide flaring out. Optimizing the HPB-radiators performance involves designing its aperture dimensions and the function that determines the H-plane taper to minimize the reflected power into the feed-waveguide while maintaining a half sine wave aperture electric field (E-field) distribution. Once the optimal HPB-radiator is designed, the design of the split-waveguide-HPB-array is similar to designing a uniform linear array. There is minimal mutual coupling between the elements through the waveguide, and for design purposes, external coupling between the elements can be ignored. The first four elements of the narrow-wall-slot-HPB-array are longitudinal-slots in the narrow wall of a rectangular waveguide, and the last element is an HPB-radiator with the same optimal performance criteria as that of the split-waveguide-HPB-array. The narrow-wall-slot-HPB-array is designed by a combination of computational and microwave network analysis techniques. First, computational analysis of the individual slots is performed separately. In the next step, each longitudinal-slot in the narrow wall of the guide is reduced to a lossy two port microwave network whose S-parameters have been obtained from the computational analysis; the loss in the network represents the power radiated by the slot. Finally, microwave network analysis is used to design a uniform linear array with a low reflected power into the feed-waveguide. The primary advantage of the split-waveguide-HPB-array over the narrow-wall-slot-HPB-array is its ability to beam steer since the inputs to its elements can be controlled separately. Since the structures are used for high power applications, the HPB-radiator\u27s H-plane taper function needs to be smooth without any sharp corners. Its design procedure, using just computational or analytical methods, was intractable. The design procedure is therefore formalized using a novel approach, which processes the computational analysis data using iterative search algorithms. This approach is made possible by mapping a design output variable that is computationally intensive, to another that requires much less computational time. This approach is based on a hypothesis that is called the \u27dimensional offset hypothesis\u27. The behavior of narrow-wall longitudinal-slots with dimensions comparable to a free-space wavelength is also characterized. The similarities they possess with wire radiators are presented. The experimental results validate the theoretical analysis results for the design of an HPB-radiator and from the microwave network analysis. The power handling capability analysis for the double-narrow-wall-slot-HPB-array and the double-split-waveguide-HPB-array is also presented.\u2

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

S band narrow-wall slotted waveguide antenna For high-power applications

This work seeks designs of novel antennas, such as the rectangular waveguide narrow-wall longitudinal-aperture antenna arrays for S band high power applications. This antenna is designed to perform as a uniform array with minimum power reflected into the feed-waveguide. Based on the configuration, the double-narrow-wall-slot-array design is proposed for higher gain and grating lobes suppression. This work also deals with the S band compact narrow-wall slot-array proposed to be rendered as a conformal antenna structure. Moreover, this work proposes a circularly polarized narrow-wall longitudinal-aperture array design to produce both vertically and horizontally polarized radiated power. In the end, this work presents and discusses a couple of mechanisms for beam-steering of S band narrow-wall longitudinal-aperture array designs. The S-band narrow-wall longitudinal-aperture array design consists of four narrow wall longitudinal-slot radiators and one H-plane-bend-radiator. The design is a combination of computational and microwave network analysis techniques. First, HFSS is used to analyze the S-parameters, phases and radiated power of the narrow-wall longitudinal-slot radiators as well as the H-plane-bend radiator. Second the microwave network is applied to design a uniform linear array by neglecting the external coupling between the elements. Finally, Full-wave analysis is used to validate the array design from microwave network analysis. The double-narrow-wall slot-array design is the best narrow-wall longitudinal-slot array design with a peak gain of approximately 15dB. It consists of two identical narrow-wall-slot-arrays with a common broad wall. It has a much more uniform aperture electric field distributuion than the single array design. As a result, a higher gain with suppressed grating lobes is achieved. The S-band curved rectangular waveguide narrow-wall longitudinal-aperture antenna is proposed to perform as a conformal antenna structure. It is based on a rectangular waveguide bend so that it can be mounted easily on vehicles. It also consists of four narrow-wall longitudinal radiators and one H-plane-bend-radiator similar to the narrow-wall longitudinal slot-array. A circularly polarized narrow-wall longitudinal-aperture array design is also discussed. It produces both vertically and horizontally polarized radiated power. The configuration verified by simulation places adjacent narrow-wall longitudinal radiators orthogonally and keeps the centers of all four narrow-wall longitudinal radiators at the same level. A study of beam-steering capability is also conducted. It is divided into two parts. One moves the main beam on the plane orthogonal to the narrow-wall and orthogonal to the broad-wall of the rectangular waveguide. The other moves the main beam on the plane orthogonal to the narrow-wall and parallel to the broad-wall of the rectangular waveguide. The S-band narrow-wall longitudinal-slot array design works well both ways. Finally, the experiment is designed and conducted to validate the theoretical analysis results for the design of S-band narrow-wall longitudinal-slot array. The results obtained lead to the conclusion that there is good agreement between the theoretical and experiment results