Precise dielectric properties determination of laminar shaped materials in a partially filled waveguide

An enhanced technique for complex dielectric properties characterization of laminar-shaped materials is presented. The technique is based upon scattering measurements of a partially-filled rectangular waveguide. The influence of the different parameters regarding the achievable accuracy have also been analyzed in order to determine the optimum sample configuration. Measurements of some commercial dielectric substrates used for printed antenna design were performed and have been used for validation purpose

Microwave Technique: A Powerful Tool for Sintering Ceramic Materials

[EN] Microwave sintering has emerged in recent years as a promising technology for faster, cheaper and eco-friendlier processing of a wide variety of materials, which are regarded as significant advantages against conventional sintering procedures. The present investigation describes a technique for sintering two different ceramic materials by microwave heating: alumina-15vol.% zirconia and hydroxyapatite nanopowders. The results show that microwave sintering achieves higher density values, excellent mechanical properties and a homogeneous microstructure at lower sintering temperatures. The densities of microwave processed samples were close to the theoretical densities, and the near-net-shape of the green body was preserved without significant dimensional changes. The main advantages of microwave heating can be summarized as follows: a more flexible process, reduced processing times and production costs, and environmental benefits. Thus, microwaves are a clear alternative to conventional heating methods, using up to 70% less energy throughout the whole sintering processThis work has been carried out under a programme that supports research and development at the Polytechnic University of Valencia under multidisciplinary projects PAID2011/059, SP20120621 and SP20120677. A. Borrell acknowledges the Spanish Ministry of Science and Innovation for her JdC contract (JCI2011-10498). A. Borrell and F. L. Penaranda-Foix want to thank the Generalitat Valenciana for the grant obtained in the frame of the Program BEST/2012.Borrell Tomás, MA.; Salvador Moya, MD.; Miranda, M.; Peñaranda Foix, FL.; Catalá Civera, JM. (2014). Microwave Technique: A Powerful Tool for Sintering Ceramic Materials. Current Nanoscience. 10(1):32-35. https://doi.org/10.2174/1573413709666131111225053S323510

Mechanical characterization of conventional and non-conventional sintering methods of commercial and lab-synthesized Y-TZP zirconia for dental applications

[EN] Ceramics for dental applications have become increasingly important in the last decades. Particularly, the introduction of yttria-stabilized zirconia tetragonal polycrystalline (Y-TZP) materials as an alternative to the manufacturing of dental implants and prosthesis has provided a powerful tool to meet the demands required for these replacements in terms of biocompatibility, toughness, hardness and optical properties. Several commercial Y-TZP materials are currently available on the market and strong efforts in research and development facilities are being carried out to improve processing of Y-TZP to fully consolidate odontological pieces. Novel processing methods for ceramic powder sintering, including Y-TZP, aim to reduce processing times and production costs significantly, while maintaining or even improving the resulting microstructure and mechanical properties of the material. One of these methods includes microwave sintering. The purpose of this study is to characterize and compare the resulting properties of Y-TZP materials after conventional sintering and the non-conventional method of microwave heating. In this work one commercial material and one laboratory-synthesized Y-TZP powder are considered. The results suggest that microwave sintering results, generally, in better mechanical properties of the material in terms of hardness and fracture toughness than conventional sintering.The authors would like to thank the financial support received from Universidad Politécnica de Valencia under project SP20120677 and Ministerio de Economía y Competitividad (MINECO) and co-funded by ERDF (European Regional Development Funds) through the project (TEC2012- 37532-C02-01). A. Borrell acknowledges the Spanish Ministry of Science and Innovation for a Juan de la Cierva contract (JCI-2011-10498). A. Presenda acknowledges the Generalitat Valenciana for his Santiago Grisolía program scholarship (REF. GRISOLÍA/2013/035). The authors would also like to acknowledge the SCSIE of the University of Valencia.Presenda Barrera, Á.; Salvador Moya, MD.; Peñaranda Foix, FL.; Catalá Civera, JM.; Borrell Tomás, MA. (2014). Mechanical characterization of conventional and non-conventional sintering methods of commercial and lab-synthesized Y-TZP zirconia for dental applications. Advances in Science and Technology. 87:151-156. https://doi.org/10.4028/www.scientific.net/AST.87.151S15115687C. Piconi, G. Maccauro, Zirconia as a Ceramic Biomaterial. Biomaterials, 20 (1999) 1‐25.M. Guazzato, M. Albakry, S. Ringer, M. Swain, Strength, Fracture Toughness and Microstructure of a Selection of All-Ceramic Materials. Dental Materials, 20 (2004) 449-456.R. M. McMeeking, A. G. Evans, Mechanics of Transformation-Toughening in Brittle Materials. Journal of the American Ceramic Society, 65 (1982) 242–246.R. Benavente, Estudio de Materiales con Coeficiente de Dilatación Controlado Sinterizados por Técnicas No-Convencionales para Aplicaciones Espaciales, 2013, Master Thesis, Instituto de Tecnología de Materiales, Universidad Politécnica de Valencia.M. Oghbaei, O. Mirzaee, Microwave versus Conventional Sintering: A Review of Fundamentals, Advantages and Applications. Journal of Alloys and Compounds, 494 (2010) 175-189.K. Niihara, R. Morena, D. P. H. Hasselman, Evaluation of KIC of Brittle Solids by the Indentation Method with Low Crack-to-Indentation Ratios. Journal of Materials Science Letters, 1 (1982) 13-16.A. Borrell, M. D. Salvador, F. Peñaranda-Foix, J.M. Cátala-Civera, Microwave Sintering of Zirconia Materials: Mechanical and Microstructural Properties. International Journal of Applied Ceramic Technology, 10 (2013) 313-320.A. Borrell, M. D. Salvador, E. Rayón, F. Peñaranda-Foix, Improvement of Microstructural Properties of 3Y-TZP Materials by Conventional and Non-Conventional Sintering Techniques. Ceramics International, 38 (2012) 39-43.J. R. Kelly, I. Denry, Stabilized Zirconia as a Structural Ceramic: An Overview. Dental Materials, 24 (2008) 289-298.S. Zinelis, A. Thomas, K. Syres, N. Silikas, G. Eliades, Surface Characterization of Zirconia Implants. Dental Materials, 26 (2010) 295-305

Low temperature degradation behaviour of 10Ce-TZP/Al2O3 bioceramics obtained by microwave sintering technology

[EN] Zirconia is one of the most used ceramics, especially for biomedical applications, due to its exceptional mechanical properties. However, it is commonly known that its properties can be diminished owing to a low temperature degradation (LTD). This phenomenon consists on a spontaneous phase transformation, from tetragonal to monoclinic, under certain conditions, which is accelerated when the samples are exposed under high levels of humidity at a temperature range between 20-300 ºC. In addition to the fact that the monoclinic phase presents worse mechanical properties than the tetragonal one, there is a volume change of 4% between phases that gives rise to defects in the material as microcracks. Due to this reason, zirconia prostheses failed catastrophically inside the human body between 1999 and 20011. Previous researches reveal that Al2O3 addition suppress the propagation of phase transformation2. Thus, the aim of the present work is to study the hydrothermal ageing of zirconia doped with ceria and toughened with alumina (10Ce-TZP/Al2O3) composite, which has been sintered by microwave employing two different frequencies: 2.45 and 5.8 GHz. Microwave heating technology is based on the absorption of electromagnetic radiation by the material, which allows the sample to be heated. So far, most microwave heating equipments use 2.45 GHz; accordingly, the novelty of this study is to employ a frequency of 5.8 GHz and to investigate its effect on LTD. LTD is carried out in an autoclaved in steam at 120 ºC and 1.2 bar, because these conditions accelerate the hydrothermal aging process3. In order to characterize the degraded samples, micro-Raman spectroscopy, AFM, nanoindentation technique and electronic microscopy have been performed. References 1. Norton, M. R., Yarlagadda, R., Anderson, G. H. J. Bone Joint Surg. Br., 2002, 84–B, 631–635. 2. Fabbri, P., Piconi, C., Burresi, E., Magnani, G., Mazzanti, F., Mingazzini, C. Dent. Mater., 2014. 3. Presenda, Á., Salvador, M. D., Moreno, R., Borrell, A. J. Am. Ceram. Soc., 2015, 98, 3680–3689.The authors thank the Generalitat Valenciana for the financial support provided to the PROMETEU/2016/040 project. A. Borrell is grateful to the Spanish Ministry of Economy and Competitiveness for her RyC contract (RYC-2016-20915).Gil-Flores, L.; Salvador Moya, MD.; Peñaranda Foix, FL.; Rosa, R.; Veronesi, P.; Leonelli, C.; Borrell Tomás, MA. (2019). Low temperature degradation behaviour of 10Ce-TZP/Al2O3 bioceramics obtained by microwave sintering technology. En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 426-432. https://doi.org/10.4995/AMPERE2019.2019.9887OCS42643

Microwave, spark plasma and conventional sintering to obtain controlled thermal expansion beta-eucryptite materials

Lithium aluminosilicate was fabricated by conventional and non-conventional sintering: microwave and spark plasma sintering, from 1200 to 1300 ºC. A considerable difference in densification, microstructure, coefficient of thermal expansion behavior and hardness and Young’s modulus was observed. Microwave technology made possible to obtain fully dense glass-free lithium aluminosilicate bulk material (>99%) with near-zero and controlled coefficient of thermal expansion and relatively high mechanical properties (7.1 GPa of hardness and 110 GPa of Young’s modulus) compared to the other two processes. It is believed that the heating mode and effective particle packing by microwave sintering are responsible to improve these properties.The authors would like to thank Dr. Emilio Rayon for performing the nanoindentation analysis in the Materials Technology institute (ITM) of the Polytechnic University of Valencia (UPV) and your financial support received of UPV under project SP20120621 and SP20120677 and Spanish government through the project (TEC2012-37532-C02-01) and cofunded by ERDF (European Regional Development Funds). A. Borrell acknowledges the Spanish Ministry of Science and Innovation for a Juan de la Cierva contract (JCI-2011-10498) and SCSIE of the University of Valencia.Benavente Martínez, R.; Salvador Moya, MD.; Borrell Tomás, MA.; García Moreno, O.; Peñaranda Foix, FL.; Catalá Civera, JM. (2015). Microwave, spark plasma and conventional sintering to obtain controlled thermal expansion beta-eucryptite materials. International Journal of Applied Ceramic Technology. 1-7. https://doi.org/10.1111/ijac.12285S17Bach, H. (Ed.). (1995). Low Thermal Expansion Glass Ceramics. Schott Series on Glass and Glass Ceramics. doi:10.1007/978-3-662-03083-7Roy, R., Agrawal, D. K., & McKinstry, H. A. (1989). Very Low Thermal Expansion Coefficient Materials. Annual Review of Materials Science, 19(1), 59-81. doi:10.1146/annurev.ms.19.080189.000423García-Moreno, O., Kriven, W. M., Moya, J. S., & Torrecillas, R. (2013). Alumina Region of the Lithium Aluminosilicate System: A New Window for Temperature Ultrastable Materials Design. Journal of the American Ceramic Society, 96(7), 2039-2041. doi:10.1111/jace.12428Chen, J.-C., Huang, G.-C., Hu, C., & Weng, J.-P. (2003). Synthesis of negative-thermal-expansion ZrW2O8 substrates. Scripta Materialia, 49(3), 261-266. doi:10.1016/s1359-6462(03)00213-6Abdel-Fattah, W. I., & Abdellah, R. (1997). Lithia porcelains as promising breeder candidates — I. Preparation and characterization of β-eucryptite and β-spodumene porcelain. Ceramics International, 23(6), 463-469. doi:10.1016/s0272-8842(96)00054-5Sheu, G.-J., Chen, J.-C., Shiu, J.-Y., & Hu, C. (2005). Synthesis of negative thermal expansion TiO2-doped LAS substrates. Scripta Materialia, 53(5), 577-580. doi:10.1016/j.scriptamat.2005.04.028Soares, V. O., Peitl, O., & Zanotto, E. D. (2013). New Sintered Li2O-Al2O3-SiO2Ultra-Low Expansion Glass-Ceramic. Journal of the American Ceramic Society, 96(4), 1143-1149. doi:10.1111/jace.12266Hu, A. M., Li, M., & Mao, D. L. (2008). Growth behavior, morphology and properties of lithium aluminosilicate glass ceramics with different amount of CaO, MgO and TiO2 additive. Ceramics International, 34(6), 1393-1397. doi:10.1016/j.ceramint.2007.03.032Ogiwara, T., Noda, Y., Shoji, K., & Kimura, O. (2011). Low-Temperature Sintering of High-Strength β-Eucryptite Ceramics with Low Thermal Expansion Using Li2O-GeO2 as a Sintering Additive. Journal of the American Ceramic Society, 94(5), 1427-1433. doi:10.1111/j.1551-2916.2010.04279.xAnselmi-Tamburini, U., Garay, J. E., & Munir, Z. A. (2006). Fast low-temperature consolidation of bulk nanometric ceramic materials. Scripta Materialia, 54(5), 823-828. doi:10.1016/j.scriptamat.2005.11.015Borrell, A., Salvador, M. D., Peñaranda-Foix, F. L., & Cátala-Civera, J. M. (2012). Microwave Sintering of Zirconia Materials: Mechanical and Microstructural Properties. International Journal of Applied Ceramic Technology, 10(2), 313-320. doi:10.1111/j.1744-7402.2011.02741.xYoshimura, M. (1998). Journal of Materials Science Letters, 17(16), 1389-1391. doi:10.1023/a:1026476430465Nishimura, T., Mitomo, M., Hirotsuru, H., & Kawahara, M. (1995). Fabrication of silicon nitride nano-ceramics by spark plasma sintering. Journal of Materials Science Letters, 14(15), 1046-1047. doi:10.1007/bf00258160Chaim, R. (2007). Densification mechanisms in spark plasma sintering of nanocrystalline ceramics. Materials Science and Engineering: A, 443(1-2), 25-32. doi:10.1016/j.msea.2006.07.092Chaim, R. (2006). Superfast densification of nanocrystalline oxide powders by spark plasma sintering. Journal of Materials Science, 41(23), 7862-7871. doi:10.1007/s10853-006-0605-7Borrell, A., Salvador, M. D., Rayón, E., & Peñaranda-Foix, F. L. (2012). Improvement of microstructural properties of 3Y-TZP materials by conventional and non-conventional sintering techniques. Ceramics International, 38(1), 39-43. doi:10.1016/j.ceramint.2011.06.035Benavente, R., Borrell, A., Salvador, M. D., Garcia-Moreno, O., Peñaranda-Foix, F. L., & Catala-Civera, J. M. (2014). Fabrication of near-zero thermal expansion of fully dense β-eucryptite ceramics by microwave sintering. Ceramics International, 40(1), 935-941. doi:10.1016/j.ceramint.2013.06.089Cheng, J., Agrawal, D., Zhang, Y., & Roy, R. (2002). Microwave sintering of transparent alumina. Materials Letters, 56(4), 587-592. doi:10.1016/s0167-577x(02)00557-8García-Moreno, O., Fernández, A., Khainakov, S., & Torrecillas, R. (2010). Negative thermal expansion of lithium aluminosilicate ceramics at cryogenic temperatures. Scripta Materialia, 63(2), 170-173. doi:10.1016/j.scriptamat.2010.03.047P. J. Plaza-Gonzalez A. J. Canos J. M. Catala-Civera J. D. Gutierrez-Cano Proceedings of the 13th International Conference on Microwave and RF Heating 447 450 2011Oliver, W. C., & Pharr, G. M. (1992). An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments. Journal of Materials Research, 7(6), 1564-1583. doi:10.1557/jmr.1992.1564Wang, S.-Y., Wang, W., Wang, W.-Z., & Du, Y.-W. (2002). Preparation and characterization of highly oriented NiO(200) films by a pulse ultrasonic spray pyrolysis method. Materials Science and Engineering: B, 90(1-2), 133-137. doi:10.1016/s0921-5107(01)00922-9Ghosh, S., Chokshi, A. H., Lee, P., & Raj, R. (2009). A Huge Effect of Weak dc Electrical Fields on Grain Growth in Zirconia. Journal of the American Ceramic Society, 92(8), 1856-1859. doi:10.1111/j.1551-2916.2009.03102.xCoble, R. L. (1961). Sintering Crystalline Solids. I. Intermediate and Final State Diffusion Models. Journal of Applied Physics, 32(5), 787-792. doi:10.1063/1.1736107Munir, Z. A., Quach, D. V., & Ohyanagi, M. (2010). Electric Current Activation of Sintering: A Review of the Pulsed Electric Current Sintering Process. Journal of the American Ceramic Society, 94(1), 1-19. doi:10.1111/j.1551-2916.2010.04210.xRybakov, K. I., Olevsky, E. A., & Krikun, E. V. (2013). Microwave Sintering: Fundamentals and Modeling. Journal of the American Ceramic Society, 96(4), 1003-1020. doi:10.1111/jace.12278Pelletant, A., Reveron, H., Chêvalier, J., Fantozzi, G., Blanchard, L., Guinot, F., & Falzon, F. (2012). Grain size dependence of pure β-eucryptite thermal expansion coefficient. Materials Letters, 66(1), 68-71. doi:10.1016/j.matlet.2011.07.107Bruno, G., Garlea, V. O., Muth, J., Efremov, A. M., Watkins, T. R., & Shyam, A. (2012). Microstrain temperature evolution in β-eucryptite ceramics: Measurement and model. Acta Materialia, 60(12), 4982-4996. doi:10.1016/j.actamat.2012.04.033Ramalingam, S., & Reimanis, I. E. (2012). Effect of Doping on the Thermal Expansion of β-Eucryptite Prepared by Sol-Gel Methods. Journal of the American Ceramic Society, 95(9), 2939-2943. doi:10.1111/j.1551-2916.2012.05338.xVaidhyanathan, B., Annapoorani, K., Binner, J., & Raghavendra, R. (2010). Microwave Sintering of Multilayer Integrated Passive Devices. Journal of the American Ceramic Society, 93(8), 2274-2280. doi:10.1111/j.1551-2916.2010.03740.

Comparison in mechanical properties of zirconium titanate (ZrTiO4) synthetized by alternative routes and sintered by microwave (MW)

[EN] At present, ZrTiO4 nanopowders are used as a dielectric in the electroceramic field, applications of catalysis, microwave telecommunications devices, pigments, composites, etc. One of the most interesting applications is the potential as structural material and similar applications that require a high thermal resistance. However, all the properties of zirconium titanate are still a subject of interest for the industrial field.12 There are several routes of synthesis of ZrTiO4; among them is the sol-gel method and lyophilization. These methods have been used to make powders or small pieces of zirconium titanate. However, structural applications require materials in large quantities, so it is necessary to identify the differences between the methods of synthesizing and allowing the preparation of powders suitable for the generation of green materials for subsequent sintering.3 To develop a new generation of nanomaterials with microstructural differences it is necessary to innovate in the sintering process. Years ago, the use of conventional oven for sintering material was the usual procedure. Nowadays, non-conventional methods as Microwave sintering (MW) are a bright way to produce high dense materials, using heating rates in reduce dwell times and lower consumption using 70%-80% less energy. 4 This reactive sintering technique achieves excellent mechanical properties, homogeneous microstructure employing lower sintering temperatures. All these energy and economic advantages generate a new vision for the future on ceramic materials and their industrial production. The main objective of this study is to make a comparison of the mechanical properties of the materials synthesized by sol-gel method and lyophilization and sintered by microwaves.The authors would like to thank to the Generalitat Valenciana for financial support received for Santiago Grisolía program scholarship (GRISOLIAP/2018/168). A. Borrell acknowledges the Spanish Ministry of Economy and Competitiveness for her RyC contract (RYC-2016-20915).Guillén Pineda, RM.; Borrell Tomás, MA.; Salvador Moya, MD.; Peñaranda Foix, FL.; Moreno, R. (2019). Comparison in mechanical properties of zirconium titanate (ZrTiO4) synthetized by alternative routes and sintered by microwave (MW). En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 433-438. https://doi.org/10.4995/AMPERE2019.2019.9892OCS43343

Mechanical properties and coefficient of thermal expansion of β-eucryptite sintered by microwave technique

[EN] Microwave non-conventional sintering technique allows obtaining fully dense glass-free β-eucryptite bulk material (∼99 %). A considerable difference in the densification, microstructure, coefficient of thermal expansion behaviour and mechanical properties, between conventional and non-conventional sintered specimens was observed. The hardness and Young’s modulus values obtained by microwaves at 1200 °C-5min have been relatively high, 6.8 GPa and 101 GPa, respectively, compared to conventional sintering (3.9 GPa and 58 GPa, respectively). Very low thermal expansion materials have been obtained in a wide temperature range including cryogenic temperatures (from -150 ºC to 150 ºC). The high heating rate along with the lower energy consumption makes microwave technique a clear alternative to other types of sintering methods.[ES] La técnica de sinterización no convencional de microondas permite obtener materiales de β-eucriptita en estado sólido cristalino con densidades cercanas a la teórica (∼99 %). Se ha observado una diferencia considerable en estos materiales respecto a la técnica convencional en términos de densificación, microestructura, coeficiente de expansión térmica y propiedades mecánicas. Los valores de dureza y módulo de Young obtenidos mediante sinterización por microondas a 1200 ºC-5 min han sido relativamente altos, 6.8 GPa y 101 GPa, respectivamente, en comparación con el material obtenido mediante horno convencional (3.9 GPa y 58 GPa, respectivamente). Los datos dilatométricos obtenidos, incluyendo el intervalo de temperatura criogénica (-150 ºC a +150 ºC), muestran un coeficiente de expansión térmica controlado y negativo en todo el rango de temperaturas. La combinación de un calentamiento rápido junto con la reducción drástica en el tiempo de ciclo y el ahorro energético, hace que la técnica de microondas sean una clara alternativa a otro tipo de calentamientos.Los autores desean agradecer al Dr. Emilio Rayón por la realización de los ensayos de nanoindentación en el Instituto de Tecnología de Materiales (ITM) de la Universidad Politécnica de Valencia (UPV). El apoyo financiero recibido de la UPV dentro de los proyectos SP20120621 y SP20120677 y, al gobierno español a través del proyecto (TEC2012-37532-C02-01). A. Borrell, agradece al Ministerio de Ciencia e Innovación su contrato de Juan la Cierva (JCI-2011-10498).Benavente Martínez, R.; Borrell Tomás, MA.; Salvador Moya, MD.; García-Moreno, O.; Peñaranda Foix, FL.; Catalá Civera, JM. (2014). Propiedades mecánicas y coeficiente de dilatación térmica de la beta-eucriptita sinterizada por la técnica de microondas. Boletín de la Sociedad Española de Cerámica y Vidrio. 133-138. https://doi.org/10.3989/cyv.xx2014S13313

Measurement of the dielectric properties of liquid crystal material for microwave applications

[EN] Liquid Crystal (LC) is an anisotropic liquid material which flows like a liquid, but at the same time its molecules have an orientational order like in the solid state [1]. Thus, LC is a promising dielectric material for designing reconfigurable devices at microwave frequencies. In order to optimize the design of reconfigurable microwave devices, accurate values of the dielectric permittivity and the loss tangent of LCs are needed. However, new LCs are not well characterized at these frequencies because of its recent use for microwave applications. Therefore, the characterization in this frequency range is required for its practical use within microwave components and devices [2]. In this work, the split-cylinder resonator method has been used for the characterization of LCs at two frequency points, i.e. 5 and 11 GHz. The method is based on the measurement of the resonance frequency and quality factor of the two states of the LC molecules for extracting the complex dielectric permittivity [3]. For achieving these two states, no electric or magnetic fields are needed, just the cell must be turned 90º inside the cavity. The dielectric properties (permittivity and loss tangent) of four different LC samples, GT3-23002 from Merck and QYPD193, QYPD142, and QYPD036 from Qingdao QY Liquid Crystal Co, have been obtained. The highest values of the dielectric anisotropy are presented for the samples QYPD036 and QYPD193, together with the highest values of the corresponding loss tangent parameters. Furthermore, it is observed for all the LCs that the loss tangent decreases and the dielectric anisotropy increases at higher frequencies, which must be taken into account in the development of reconfigurable microwave devices.Sanchez, J.; Nova Giménez, V.; Bachiller Martin, MC.; Villacampa, B.; De La Rua, A.; Kronberger, R.; Peñaranda Foix, FL.... (2019). Measurement of the dielectric properties of liquid crystal material for microwave applications. En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 506-510. https://doi.org/10.4995/AMPERE2019.2019.998350651

Filtros Paso Bajo de Microondas realizados con Saltos de Impedancia

Este vídeo describe el procedimiento de síntesis de un filtro paso bajo de microondas con saltos de impedancia. Es decir, líneas de alta y baja impedancia alternativamentehttps://polimedia.upv.es/visor/?id=68db2c47-c6d1-5746-ad00-14ee3a1b2e11Peñaranda Foix, FL. (2011). Filtros Paso Bajo de Microondas realizados con Saltos de Impedancia. http://hdl.handle.net/10251/1021

Permitividad efectiva de una línea microstrip

Calcula la permitividad relativa efectiva de una línea microstriphttps://laboratoriosvirtuales.upv.es/eslabon/eps_r_efPeñaranda Foix, FL. (2008). Permitividad efectiva de una línea microstrip. http://hdl.handle.net/10251/66