Flexible and Efficient Computer-Aided Design Tool for Advanced Comb-Line Rectangular Waveguide Filters

A very flexible and efficient computer-aided design (CAD) tool, specifically suited for advanced comb-line rectangular waveguide filters, is presented in this work. The developed software tool, which makes use of a full-wave analysis technique based on the Boundary Integral—Resonant Mode Expansion method, allows loading the considered comb-line resonators with any number of radially symmetrical partial-height metallic posts. The implemented CAD tool also allows dealing with coupling windows of arbitrary cross-section, thus drastically enhancing the flexibility of the CAD process. The excitation of the analyzed components, which is performed using generalized coaxial probes, has also been integrated in the implemented software tool, thus achieving a full-wave electromagnetic characterization of the whole component. Furthermore, a novel simple procedure to efficiently connect all the obtained wide-band matrices is proposed. To validate the accuracy and efficiency of this novel CAD tool, several new designs concerning advanced band-pass comb-line waveguide filters are presented. The accuracy of the developed CAD tool has been successfully validated by comparing the obtained results with numerical data provided by a commercial tool based on the finite-element method

Systematic procedure for the efficient design of folded waveguide comb-line filters

[EN] A systematic procedure for the efficient design of folded waveguide comb-line filters is presented. The proposed strategy is based on dividing the design process in more simple stages, in order to reduce the number of variables to be optimized in each step of the design process. The electrical response of an equivalent circuit model of the waveguide component considered in each step is used as a target response. Moreover, a method for obtaining an initial value for some key dimensions of the filter is also addressed. Finally, an S-band 6-pole folded comb-line filter has been successfully designed following the proposed design strategy.San-Blas, AA.; Pérez-Guijarro, J.; Boria Esbert, VE.; Guglielmi, M. (2019). Systematic procedure for the efficient design of folded waveguide comb-line filters. IEEE. 1-4. https://doi.org/10.1109/NEMO.2019.8853707S1

Overlooked gall-inducing moths revisited, with the description of Andescecidium parrai gen. et sp. n. and Oliera saizi sp. n. from Chile (Lepidoptera, Cecidosidae)

There are still many gall systems associated with larvae of Lepidoptera in which the true gall-inducers have not been identified to species. Reports on misidentification of gall inducers have been recurrent for these galls, particularly in complex gall-systems that may include inquilines, kleptoparasites, and cecidophages, among other feeding guilds such as predators and parasitoid wasps. Here we describe and illustrate the adults, larvae, pupae and galls, based on light and scanning microscopy, of Andescecidium parrai gen. et sp. n. and Oliera saizi sp. n., two sympatric cecidosid moths that are associated with Schinus polygamus (Cav.) Cabrera (Anacardiaceae) in central Chile. Adults, immatures, and galls of the former did not conform to any known cecidosid genus. Galls of A. parrai are external, spherical, and conspicuous, being known for more than one century. However, their induction has been mistakenly associated with either unidentified Coleoptera (original description) or Oliera argentinana Br糨es (recently), a distinct cecidosid species with distribution restricted to the eastern Andes. Galls of O. saizi had been undetected, as they are inconspicuous. They occur under the bark within swollen stems, and may occur on the same plant, adjacent to those of A. parrai. We also propose a time-calibrated phylogeny using sequences from mitochondrial and nuclear loci, including specimens of the new proposed taxa. Thus in addition to clarifying the taxonomy of the Chilean cecidosid species we also tested their monophyly in comparison to congeneric species and putative specimens of all genera of Neotropical and African cecidosids.Fil: Silva, Gabriela T.. Universidade Federal do Rio Grande do Sul; BrasilFil: Moreira, Gilson R. P.. Universidade Federal do Rio Grande do Sul; BrasilFil: Vargas, Héctor A.. Universidad de Tarapacá de Arica; ChileFil: Gonçalves, Gislene L.. Universidade Federal do Rio Grande do Sul; Brasil. Universidad de Tarapacá de Arica; ChileFil: Mainardi, Marina D.. Universidade Federal do Rio Grande do Sul; BrasilFil: San Blas, Diego German. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa; ArgentinaFil: Davis, Donald. National Museum of Natural History; Estados Unido

Compensation of the impact of low-cost manufacturing techniques in the design of E-plane multiport waveguide junctions

In this work, a full-wave tool for the accurate analysis and design of compensated E-plane multiport junctions is proposed. The implemented tool is capable of evaluating the undesired effects related to the use of low-cost manufacturing techniques, which are mostly due to the introduction of rounded corners in the cross section of the rectangular waveguides of the device. The obtained results show that, although stringent mechanical effects are imposed, it is possible to compensate for the impact of the cited low-cost manufacturing techniques by redesigning the matching elements considered in the original device. Several new designs concerning a great variety of E-plane components (such as right-angled bends, T-junctions and magic-Ts) are presented, and useful design guidelines are provided. The implemented tool, which is mainly based on the boundary integral-resonant mode expansion technique, has been successfully validated by comparing the obtained results to simulated data provided by a commercial software based on the finite element method.All the data necessary to understand, evaluate, replicate, and generate the figures and results presented in this paper have been included in the present manuscript. A full-wave custom code and the commercial software Ansys HFSS have been used to generate the simulated results provided by the authors. This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under the Research Projects TEC2013-47037-C5-1-R and TEC2013-47037-C5-4-R.San Blas Oltra, ÁA.; Roca, JM.; Cogollos Borras, S.; Morro, JV.; Boria Esbert, VE.; Gimeno Martinez, B. (2016). Compensation of the impact of low-cost manufacturing techniques in the design of E-plane multiport waveguide junctions. Radio Science. 51(6):619-628. https://doi.org/10.1002/2016RS006027S61962851

Polarization conversion on nanostructured metallic surfaces fabricated by LIPSS

Conference on Laser-Based Micro-and Nanoprocessing (LBMP) at Photonics West Conference (13ª. 2019. San Francisco, California). ISBN: 978-1-5106-2455-9 © 2019 SPIE. This work is part of the following projects: ECOGRAB, funded by the Government of Spain under the RETOS COLABORACIÓN I+D+i programme. LASER4SURF has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 768636.Waveplates modify polarization by generating a phase change. Laser Induced Periodic Surface Structures (LIPSS) have recently started to be studied as waveplates due to the birefringence in-duced by the nanoripples, easily fabricated in a one-step process by laser, where LIPSS morphology is defined by the characteristics of the laser process parameters and the substrate material. The optical properties of these waveplates are defined by LIPSS parameters such as period, depth or width of the ripples. In this work we have deposited thin film coatings on stainless steel samples containing LIPSS for different coating thickness and composition. Results show that thin film coatings are a good candidate for the tunability of LIPSS birefringence since the coating modifies the induced polarization change and reflectivity of the sample depending on coating thickness and composition, as expected from numerical simulations.Depto. de ÓpticaFac. de Ciencias FísicasTRUEUnión Europea. H2020Ministerio de Ciencia e Innovación (MICINN)pu

LIPSS manufacturing with regularity control through laser wavefront curvature

Laser-Induced Periodic Surface Structures (LIPSS) manufacturing is a convenient laser direct-writing technique for the fabrication of nanostructures with adaptable characteristics on the surface of virtually any material. In this paper, we study the influence of 1D laser wavefront curvature on nanoripples spatial regularity, by irradiating stainless steel with a line-focused ultrafast laser beam emitting 120 fs pulses at a wavelength of 800 nm and with 1 kHz repetition rate. We find high correlation between the spatial regularity of the fabricated nanostructures and the wavefront characteristics of the laser beam, with higher regularity being found with quasi-plane-wave illumination. Our results provide insight regarding the control of LIPSS regularity, which is essential for industrial applications involving the LIPSS generation technique

Femtosecond laser fabrication of LIPSS-based waveplates on metallic surfaces

A fast and reliable method for the fabrication of polarization modifying devices using femtosecond laser is reported. A setup based on line focusing is used for the generation of LIPSS on stainless steel, processing at different speeds between 0.8 and 2.4 mm/s with constant energy per pulse of 1.4 mJ. SEM and AFM characterizations of the LIPSS show a progressive increase in period as the processing speed increases, while height remains approximately constant in the studied range. Optical characterization of the devices shows an induced change in the polarization of the reflected beam that varies with the processing speed, which allows a controlled fabrication of these devices

Taxonomy of five neglected South American species of Dargida Walker (Lepidoptera: Noctuidae).

Abstract The taxonomy of five South American species of Dargida Walker currently allocated in Leucania Ochsenheimer (four species) and in Lasionycta Aurivillius (one species) is revised. Leucania roseilinea (Köhler, 1947), Leucania phaeoneura Hampson, 1913, Leucania mocoides Dognin, 1897, Leucania alboradiata (Hampson, 1905) and Lasionycta radiata (Köhler, 1966), are here combined with the genus Dargida Walker for the first time (comb. nov.). Two new synonyms are proposed, Leucania roseilineoides Poole, 1989 is an objective junior synonym of Borolia roseilinea Köhler, 1947 (syn. nov.) (ICZN 51.4), and B. lilloana Köhler, 1947 is a subjective junior synonym of Leucania phaeoneura Hampson, 1913 (syn. nov.). Lectotype for Borolia lilloana is designated to ensure nomenclatural stability and recognizability of the taxon. All species are redescribed and discussed, and the habitus and male and female genitalia (when available) are given, as well as an updated geographical map