Microstrip to Double Ridge Empty Substrate Integrated Waveguide Transitions Based on Exponential and Superelliptical Dielectric Taper

[EN] The Empty Substrate IntegratedWaveguides (ESIW) maintain the advantages of the Substrate Integrated waveguide (SIW) (i.e. low-volume, low profile, lightweight, easy manufacturing, and integration in a planar circuit board), and present lower losses and higher quality factors in resonators due to the propagation of the fields through air, instead of through lossy dielectric as in SIW. The operational (monomode) bandwidth of the ESIW can be increased with the Single Ridge ESIW (SRESIW). However, the bandwidth can be further increased with the Double Ridge ESIW (DRESIW). In this paper, a brief study of possible DRESIW geometries has been performed, and two transitions from microstrip line (MS) to DRESIW with a dielectric taper geometry based on different equations are proposed. The new wideband transitions present simulated return losses in back-to-back configurations greater than 20 dB in more than a 95% fractional bandwidth. The transition that presents a better compromise between return losses, bandwidth and ease of fabrication is manufactured. The measured return and insertion losses are better than 19.7 dB and 1.5 dB, respectively, in a 96.4% fractional bandwidth.This work was supported by the Ministerio de Ciencia e Innovacion, Spanish Government, under Project PID2019-103982RB-C44 and Project PID2019-103982RB-C41.Herraiz Zanón, D.; Esteban González, H.; Herraiz, D.; Vidal Pantaleoni, A.; Belenguer, Á.; Boria Esbert, VE. (2021). Microstrip to Double Ridge Empty Substrate Integrated Waveguide Transitions Based on Exponential and Superelliptical Dielectric Taper. IEEE Access. 9:165745-165753. https://doi.org/10.1109/ACCESS.2021.3134089165745165753

Low-Loss Periodically Air-Filled Substrate Integrated Waveguide (SIW) Band-Pass Filters

ABSTRACT The electrical response of low-frequency band-pass filters based on periodic substrate integrated waveguide (SIW) technology typically shows permitted and forbidden frequency bands. Therefore, this type of filters can be designed using a conceptually very simple and efficient procedure based exclusively on the study of the dispersion properties of the periodic structure. In this paper, we go a step further with the design of a periodically air-filled SIW band-pass filter in which part of the dielectric substrate is removed to reduce insertion losses, and whose unit cell parameters, which are directly related to the center frequency (fc) and bandwidth (BW) of the first passband, and also to the first stopband or bandgap (BG) of the structure, have been appropriately selected for filtering purposes, thus providing some useful design rules. Furthermore, we apply the concept of glide symmetry for achieving a much larger fractional bandwidth (FBW) than that obtained in conventional air-filled SIW filters found in the technical literature. Finite implementations of both periodic structures with and without glide symmetry have been analyzed, showing their filtering response for validation purposes. Additionally, to overcome the matching level restrictions in the resulting air-filled periodic SIWs, a microstrip-to-SIW transition including a novel coupling iris is proposed. A prototype of the proposed air-filled glide-symmetric periodic SIW filter has been manufactured and experimentally validated, illustrating the potential of this technique to obtain large FBWs that can not be achieved in conventional air-filled SIW filters. The proposed filter proves to be a good candidate for millimeter wave applications

Manufacturing Methods Based on Planar Circuits

Manufacture of hybrid 3D-planar circuits, especially those incorporating empty waveguides on substrates, can benefit from most standardized planar fabrication processes, although they are not exactly the same. For this reason, planar circuit manufacturing methods must be adapted to the requirements of these new circuits. Through numerous fabrications and successful designs, several enhancing strategies have been established to improve all the manufacturing phases to achieve better results. They all have been proved in the following substrate-integrated technologies for the manufacturing of microwave devices: ESIW, ESICL, continuous profile, and microstrip. Thanks to these improvements, good-quality prototypes such as transitions, filters, circulators, couplers, antennas, among others, have been fabricated. Throughout the next chapter, these strategies applied along the manufacturing process will be explained: from the first manufacturing phase to the final welding of the whole circuit and taking into account external elements such as wires that may be present in these structures. For this purpose, some devices that have been published will be used as examples

GITT. Diseño, fabricación y caracterización de una transición microstrip-ESIW-E en banda Ka

El principal objetivo de este proyecto fin de grado es diseñar y fabricar un dispositivo ope- rativo y funcional para comunicaciones satélites en la banda de frecuencias Ka. Se propone fabricar un dispositivo similar al creado por A.Belenguer, JuanCano, HectorEsteban, EduardoArtal y VicenteBoria[1]en una banda frecuencial distinta y con un filtro paso banda añadido. Mediante una tecnología que está a la orden del día como son las guías integradas en sus- tratos vacíos (ESIW) se plantea una geometría en plano E aprovechando el gran número de soluciones ya disponibles en el mercado. Se hablará también de otras tecnologías similares. Posteriormente se diseñará también por separado un filtro que se integrará en la transición, Será un tipo de filtro Chebyshev centrado en 30GHz. Se utilizará el programa matemático Matlab para los cálculos teóricos y el programa de Simulación de onda completa CST para las simulaciones correspondientes del dispositivo. Después del proceso de optimización se procederá a su fabricación con las máquinas y el material del grupo de investigación donde se desarrolla este proyecto. Una vez fabricado se valorará el comportamiento de un dispositivo fabricado en la realidad y se comparará con otros dispositivos similares. Este proyecto se ha desarrollado dentro del grupo de investigación Gamma en la Escuela Politécnica de Cuenca de la Universidad de Castilla-La Mancha

Design of a Wide-Bandwidth, High-Gain and Easy-to-Manufacture 2.4 GHz Floating Patch Antenna Fed with the Through-Wire Technique

This paper presents a feasibility study for designing a floating patch antenna structure fed with a probe from a microstrip. The main premise is to eliminate the dielectric in the patch design, which is equivalent to having an air dielectric and leads to the necessity of proper support to fasten the patch in the air. The novelty of this paper is that this new device, apart from being fed with the though-wire technique directly from the microstrip line, has to be, by design, robust and easy to manufacture, and, at the same time, it has to present, simultaneously, good values in all of the performance indexes. A prototype has been designed, manufactured, and measured with good performance results: a bandwidth higher than 10% around 2.4 GHz, a radiation efficiency higher than 96%, a 9.63 dBi gain, and a wide beamwidth. The main advantages of this prototype, together with its good performance indexes, include its low fabrication cost, low losses, light weight, robustness, high integration capability, the complete removal of the dielectric material, and the use of a single post for feeding the patch while simultaneously fixing its floating position

A new blood DNA methylation signature for Koolen-de Vries syndrome: Classification of missense KANSL1 variants and comparison to fibroblast cells

Pathogenic variants in KANSL1 and 17q21.31 microdeletions are causative of Koolen-de Vries syndrome (KdVS), a neurodevelopmental syndrome with characteristic facial dysmorphia. Our previous work has shown that syndromic conditions caused by pathogenic variants in epigenetic regulatory genes have identifiable patterns of DNA methylation (DNAm) change: DNAm signatures or episignatures. Given the role of KANSL1 in histone acetylation, we tested whether variants underlying KdVS are associated with a DNAm signature. We profiled whole-blood DNAm for 13 individuals with KANSL1 variants, four individuals with 17q21.31 microdeletions, and 21 typically developing individuals, using Illumina's Infinium EPIC array. In this study, we identified a robust DNAm signature of 456 significant CpG sites in 8 individuals with KdVS, a pattern independently validated in an additional 7 individuals with KdVS. We also demonstrate the diagnostic utility of the signature and classify two KANSL1 VUS as well as four variants in individuals with atypical clinical presentation. Lastly, we investigated tissue-specific DNAm changes in fibroblast cells from individuals with KdVS. Collectively, our findings contribute to the understanding of the epigenetic landscape related to KdVS and aid in the diagnosis and classification of variants in this structurally complex genomic region