Programa del congreso

Empty substrate integrated waveguide (ESIW) is a transmission line that appeared to improve the well-known substrate integrated waveguide (SIW). This improvement consists of removing the dielectric substrate that does not allow the SIW performance to be good at high frequency. As it is a relatively new technology, not all the devices that have been presented based on SIW technology have been designed in ESIW. One of the devices that has not been designed yet in ESIW is a circulator. Thus, a ferrite-based Y-junction circulator designed and fabricated in ESIW technology to operate at a central frequency of 30 GHz is presented. The results obtained by the full wave simulations and the experimental measurements exhibit the correct operation of the circulator at Ka band.

In this work, we present a new compact topology of interdigital bandpass filters implemented in coaxial waveguide technology. Compared to classical coaxial resonators, which are typically loaded with cylindrical metallic posts, the resonators that we propose are based on rectangular cavities loaded with flat metallic strips of a finite thickness. The main advantages of the proposed topology are compactness and

low-cost practical realization. The design process, which is based on the calculation of the input/output and the inter-resonator couplings, employs the well-known Aggressive Space Mapping technique, with the aim of reducing the overall computation effort. In order to validate the new proposed topology and the design procedure, interdigital filters of orders 3 and 5 operating in the S-band have been designed. For validation purposes, the obtained results have been successfully compared to data provided by two different full-wave software tools (Ansys HFSS and CST Studio Suite).

Este artículo muestra la solución adoptada para suprimir una interferencia generada por un potente radar de basura espacial a 1,75 Km de la estación RAEGE Santa María.Dada la alta sensibilidad requerida en los receptores radioastronómicos, los filtros superconductores de alta temperatura (HTS) son la mejor solución a adoptar para degradar en la menor medida de lo posible los receptores ultra sensibles utilizados. Por ello, un filtro HTS basado en resonadores espirales ha sido diseñado, fabricado e instalado en la estación.

El rechazo de este filtro ha permitido al radiotelescopio RAEGE Santa María observar en presencia de este radar.

This paper presents the practical implementation of a diplexer, for satellite applications designed using Empty Substrate Integrated Waveguide (ESIW) technology. The proposed diplexer comprises two bandpass ESIW filters based on inductive windows and a resonant T-junction. The filters are centered at 11.575 GHz and 11.825 GHz, both with bandwidths of 155 MHz. The proposed diplexer demonstrates return and insertion losses better than 23 dB and lower than 0.30 dB, respectively, as well as an isolation level better than 30 dB. This technology enables the creation of a high-performance diplexer with a focus on Size, Weight, Power, and Cost (SWaP-C) as crucial indexes.

We introduce a novel reflectarray unit cell based on a SIW cavity resonator, designed for operation at 18.7 GHz. It can achieve a full phase cycle of phase shifting and low losses, while keeping manufacturing requirements simple. Furthermore, by relying on a resonant cavity instead of open elements, inter-cell coupling effects are reduced. This can lower the approximation errors resulting from using the cell response under a fully periodic environment during the design process.

This contribution describes a dual-band polarizing reflectarray antenna for small-satellite communications. The proposed an-tenna has been designed to convert the incident dual-linearly polarized field into dual-circular polarization in K and Ka bands, generating a high gain beam as well. The unit-cell is composed of two layers of metallization, where each layer has orthogonal groups of dipoles and is designed to independently operate at a different frequency. The polarization conversion process has been generalized to operate with non-stacked dual polarization elements, which allows to use a single dielectric layer per operating frequency. Simulated results of a 20 cm polarizing reflectarray antenna with a dual-layer configuration show a maximum gain larger than 30 dBi and an axial ratio below 1.5 dB at both design frequencies (19.7 and 29.5 GHz).

In this contribution, two designs of dual-band reflectarray surfaces are proposed for coverage-enhancing applications in millimeter-wave 5G networks. The first design is based on a two-layer reflectarray panel with simultaneous operation at 28 and 39 GHz, which is able to generate two independent collimated beams in dual polarization (one beam at each frequency). The second design is based on a single-layer reflectarray that operates at 28 and 60 GHz. In this case, a beamforming technique has been applied to broaden the beams in the azimuth plane, in order to cover a wider angular range. The proposed reflectarrays can be used to enable wireless communications in millimeter-wave networks, providing coverage of blind zones in both indoor and outdoor scenarios.

Cost-effective multibeam millimeter wave antenna solutions are required to enable the deployment of 5G NR . The complex trade-off between system complexity and RF requirements (such as high gain, number of beams, beam scanning capability, ) needs to be carefully optimzed. Transmit-arrays (TAs) can provide a low-cost solution for multibeam operation by having aN feeding array placed at a given focal distance. However, the maximum number of feeds and cross-over levels are constrained by the focal distance to aperture diameter ratio (F/D). On the one hand, reducing the F/D allows designing more compact feeding array elements, on the other hand, it limits the maximum angle coverage due to scanning aberrations. In this work, we show that a TA optimized for operating simultaneously with low F/D and wide-angle coverage can improve the performance of this classical configuration. We design a Ka-band multibeam antenna with a TA fed by a 19x5 array of standard WR38 waveguide operating with F/D=0.34. It provides 25 dBi of gain with scan losses below 3 dB when scanning in a zenith plane up to -55 degrees, covering 80 degrees (-55 to 25 degrees) with cross-over levels around 3 dB.

Este trabajo presenta la caracterización de la conductividad efectiva de los materiales de fabricación aditiva utilizados para la manufactura de dispositivos para comunicaciones de alta frecuencia. Tanto el tipo de material, la porosidad, la rugosidad, como la oxidación disminuyen el valor de dicha conductividad llevando a un incremento en las pérdidas de inserción de los dispositivos fabricados. Para la caracterización se ha diseñado un resonador de cavidad en banda X sobre guía de onda rectangular y se ha medido el factor de calidad de diferentes realizaciones con técnicas y materiales diversos. Se han obtenido valores de hasta 17.70 $MS/m$ para materiales poliméricos metalizados y de hasta 5.32 $MS/m$ para aleaciones metálicas.

Empty Substrate Integrated Waveguides (ESIW)

integrate hollow 3D waveguides into printed circuit boards

(PCBs), thereby creating an empty waveguide with reduced

height while maintaining low cost, low profile, and easy in-

tegration. Several transitions have been proposed to connect

ESIW circuits to microstrip lines. However, these transitions

generally increase the complexity of the manufacturing process

and cannot be directly connected to measurement equipment.

Therefore, in this communication, a direct coaxial-to-ESIW

transition based on magnetic coupling is proposed. This structure

can be manufactured with reduced complexity, requiring only

simple cuts and metalization. An equivalent circuit model has

been proposed, which provides initial values for the transmission

parameters, and reduces the optimization time by 20%.

This article presents the design and manufacturing

of a fully metallic X-band bandpass filter in coaxial-line tech-

nology. The device is 3D-printed as a self-supported structure

without any dielectric inside. A short-circuit λ/4 parallel stub

bandpass filter an electrical connection between the inner and

outer coaxial-line conductors, and provide the required me-

chanical support for the self-supported 3D-printing process. To

enhance filter out-of-band performance, a second stage consisting

of a stepped-impedance low-pass filter is integrated, also using

coaxial-line technology. Both filters are designed separately and

then combined to achieve desired frequency specifications. A

prototype with a passband at X-band (between 8 and 12 GHz)

is manufactured using Selective Laser Melting, showing exce-

llent agreement between simulations and measurements. This

approach promises highly integrated, multifunctional monoblock

coaxial filters with additional benefits such as increased RF

shielding and protection against electrostatic discharge.

El efecto multipactor plantea un reto importante en los dispositivos de RF y microondas de alta potencia, como los filtros combline, ya que afecta a la integridad de la señal y al rendimiento del dispositivo. En este artículo, proponemos emplear un perfil de superficie corrugado para mitigar este efecto. Mediante simulaciones numéricas, demostramos que la introducción de una superficie corrugada suprime significativamente la aparición y propagación de descargas multipactor dentro de la estructura del filtro. El perfil corrugado altera eficazmente las condiciones propicias para la formación de avalanchas de electrones, aumentando así el nivel umbral de ruptura y reduciendo la probabilidad de degradación de la señal inducida por el multipactor. Además, exploramos la influencia de diversos parámetros geométricos del perfil corrugado en la supresión del efecto multipactor, proporcionando información sobre las consideraciones de diseño óptimas para mitigar este fenómeno. Nuestros hallazgos no sólo ofrecen una valiosa guía para el desarrollo de filtros combline robustos y fiables, sino que también contribuyen a una comprensión más amplia de las técnicas de supresión de multipactor en aplicaciones de RF y microondas de alta potencia.

In this work, the practical design of a Ka-band

diplexer and triplexer in half-mode groove gap waveguide (HMGGW)

technology is proposed. The first device is composed of

two bandpass HM-GGW filters, an E-plane T-junction and the

corresponding transitions to the input/output WR28 rectangular

waveguide ports. The second one has a manifold herringbone

configuration where three bandpass HM-GGW filters are directly

coupled on the common short line without the use of stubs.

In order to demonstrate the applicability of this technology, a

diplexer prototype has been successfully fabricated, showing inband

measured return and insertion losses of 21 dB and 0.87 dB

in the lower band, 16 dB and 0.86 dB in the upper band, and a

good isolation level (better than 32.5 dB) in the whole operational

frequency range. This good electrical behaviour demonstrates

that HM-GGW is an attractive technology for the design of high

frequency components, thus helping to reduce its size respect to

the equivalent component in the classical GGW technology.

Por hacer

The development of smart communications technologies brings new capabilities to the packaging industry, notably enhancing traceability within logistical operations. Radio Frequency IDentification (RFID) technologies hold significant promise in this regard but also pose challenges due to their expense and issues concerning recycling. Chipless RFID technology emerges as an alternative by eliminating the need for encoded chips and improving sustainability. This work introduces a chipless RFID system featuring an affordable reader designed for integration into packaging applications utilizing paper substrates. In this sense, 2-D geometrical patterns printed with conductive ink on paper-based substrates are analyzed, comparing them with printed circuit boards employing FR-4 substrate. The reader is developed utilizing conventional software-defined radio (SDR) platforms within the 0–6 GHz and 0–12 GHz frequency ranges, avoiding the use of a vector network analyzer (VNA) equipment.

In this contribution, the design of a novel logarithmic-spiral-shaped (LSS) anisotropic dielectric polarizer is presented for millimeter-wave applications within the Ka-band (28-30 GHz). The proposed antenna is composed of a conical horn fed by a waveguide dual-mode converter (DMC), where the TE01 and TM01 modes are independently excited to generate linearly azimuthal polarized and linearly radial polarized conical beam radiation patterns, respectively. The horn antenna is loaded with the novel LSS dielectric polarizer, which converts the linearly radial polarized wave generated by the excitation of the TE01 mode into a right-handed circularly polarized (RHCP) wave and the linearly azimuthal polarized wave generated by the excitation of the TM01 mode into a left-handed circularly polarized (LHCP) wave. In order to experimentally validate the proposed design, both the DMC along with the conical horn antenna and the novel LSS dielectric polarizer are manufactured by means of distinct 3D printing techniques. An excellent agreement between simulations and measurements is achieved.

This paper explores the potential of combining additive manufacturing (AM) with printed circuit board (PCB) technology for the fabrication of radio frequency (RF) components and circuits. This approach seeks to leverage the design freedom offered by AM while capitalizing on the established processes and design knowledge associated with PCB manufacturing. A helical microstrip line segment is chosen as the test vehicle for this study. The paper proposes a procedure for embedding this 3D structure into a printed circuit board (PCB) substrate. Electrical connectivity and mechanical stability are both considered during the definition of the embedding steps. To demonstrate the functionality of the proposed method for the design of more complex structures, two embedded helical microstrip line segments are combined to form a compact 2-way Wilkinson power divider/combiner suitable for operation at the low RF frequency band.

La fabricación aditiva (AM) se puede aplicar a nuevos escenarios donde las técnicas sustractivas tradicionales limitan la geometría y la libertad de ensamblaje. Uno de estos escenarios es el desarrollo de antenas, donde la AM ofrece la capacidad de implementar geometrías de alta complejidad, reduciendo el peso y coste de los dispositivos. Este trabajo presenta el proceso de fabricación aditiva de dos antenas MIMO de cuatro puertos con cavidad trasera utilizando tecnología de impresión 3D SLA. Los dispositivos impresos se metalizaron mediante un proceso autocatalítico de baños químicos. Finalmente, se midieron sus respuestas frecuenciales, ganancia, eficiencia, diagramas de radiación y peso, y se compararon con las fabricadas mediante métodos tradicionales de fresado sobre metal. La respuesta electromagnética de las antenas de AM es excelente y comparable con las fabricadas con técnicas sustractivas.

This communication aims to demonstrate the fea-

sibility of manufacturing complex structures through additive

manufacturing with conductive material. Enabling more intri-

cate designs and greater detail to meet the necessary specifi-

cations in today’s context. A comparison is conducted on the

performance of two conical horns, Ka-band and M-band, whose

manufacturing requirements are significantly different.

This paper presents a 3D-printed prototype of a novel top-metalized Dielectric Resonator Antenna (DRA). The inclusion of top metallization induces a modification in the boundary conditions, resulting in a frequency reduction in the fundamental mode of the DRA. Still, it does not degrade its radiation performance. The dielectric part is manufactured using fused deposition modeling (FDM) printing techniques and a commercially available Zirconia-loaded filament. The prototype presents a –10-dB bandwidth from 2.54 to 2.68 GHz with a minimum of –21 dB at 2.60 GHz. The radiation maxima occur in the top and bottom directions, with a simulated gain of 2.7 dBi. Thus, a low-cost and fast method to implement and manufacture a miniaturized DRA is presented.

This communication proposes an all-metal radial-line slot array antenna with a tilted beam, intended to mm-wave communications. An azimuthal variation of the propagation constant within the feeding waveguide is created by a non-uniform bed of nails, tailoring each pin height accordingly. When feeding a uniformly-spaced array with such inhomogeneous waveguide, the main beam tilts within a defined plane. Moreover, if such a waveguide illuminates a non-uniformly spaced slot array, beam-steering capability can be achieved by simply rotating the bottom plate with the bed of nails. This concept is intended to be experimentally validated through the fabrication of a prototype using additive manufacturing.

Advanced Driver Assistance Systems (ADAS) heavily rely on radar technology, particularly within the 76-81 GHz band, for precise obstacle detection and enhanced road safety. This paper introduces a novel metal-only antenna designed using gap waveguide technology. The antenna, featuring a scalable 1×8 slotted array fed through groove gap waveguide technology, offers multi-channel and multibeam operation, making it adaptable to various traffic scenarios.

Key features of the antenna include low transmission losses and robust obstacle detection capabilities within the 76-81 GHz band, crucial for ADAS applications. Its metal-only construction allows for integration into vehicle chassis, optimizing performance within automotive frequency bands.

Validation through simulations using CST Microwave Studio confirms the behavior and performance of the antenna. Results suggest potential as a candidate for antennas capable of multibeam performance in the E-band, underscoring its suitability for radar-based ADAS applications.

This work introduces a metal-only slot array built upon groove gap waveguide technology. This metal-only design facilitates seamless integration into vehicle chassis and ensures minimal losses within the automotive frequency bands. The fully integrated feeding network, featuring a -3dB power splitter, offers the flexibility of multi-port feeding. This adaptability has proven particularly valuable in achieving beam scanning, as changing the feeding port enables this capability. Furthermore, the multiport configuration has the potential to support multiple input/output channels, enhancing the extraction of additional angular information for a wide range of applications.

This paper presents a fully metallic radiating element that produces dual circular polarization over a wide bandwidth. A quasi-square waveguide section with a pair of corrugated walls is used, which converts ±45º linear polarization into dual circular polarization. The inclusion of periodic corrugations slows the propagation of one of the fundamental modes, leading to a phase difference exhibiting parabolic behavior. This significantly broadens the range in which a pure circular polarization of less than 1 dB of axial ratio can be attained. The behavior of the semi-corrugated waveguide is studied, and its dimensions are analyzed as a function of the bandwidth and required length. Two versions of the element with different heights and bandwidths are designed. The proposed fully metallic radiating element has small dimensions, which allow for integration into an array with low profile, while its versatile design enables the attainment of large bandwidths with pure dual circular polarization.

En este trabajo se propone un análisis de distintos métodos para la obtención de las propiedades dieléctricas de materiales de impresión 3D. En el diseño de dispositivos de microondas fabricados mediante impresión 3D, es esencial conocer con precisión las propiedades dieléctricas de los materiales empleados. Este trabajo compara tres métodos aplicados en materiales dispersivos (TW-CON175BK) y no dispersivos (PLA, ABS, Preperm-dk3, Preperm-dk10), para identificar las técnicas que obtienen las características de cada material de forma precisa. Las muestras se fabrican con la anchura y altura de las guías de onda estandarizadas WR-90 y WR-137. La longitud de las muestras depende de las propiedades de absorción del material, siendo TW-CON175BK el único cuya longitud es más corta respecto a las secciones de 51 mm empleadas en el resto de materiales. Se mide la respuesta de los parámetros [S] para cada material, y se aplican los métodos, proporcionando resultados favorables para materiales no dispersivos, y ajustando correctamente las características del material dispersivo únicamente con dos de estos métodos.

In this contribution a water drop Luneburg lens is presented. These types of antennas are very interesting in contexts such as mobile communications. With the rise of 5G, especially in the millimeter band, new radiant systems are necessary to solve the problems involved. With the increase in frequency and, therefore, propagation losses, high gain and efficiency antennas are needed. This is why devices such as geodesic lenses are a very attractive solution since they eliminate dielectric losses and can present a high gain. Additionally, their multiport and angular scanning capabilities make them highly desirable for MIMO system implementation. Additionally, thanks to advances in the development of additive manufacturing technologies, this type of geodesic lenses can have their manufacturing process greatly simplified. Light devices can be obtained at very low cost and granting great performance.

Additive Manufacturing Laser Powder-Bed Fusion (AM LPBF) technique is evaluated to manufacture monolithic antennas in metal, simplifying the conventional procedure based on, first, manufacturing a dielectric skeleton, and then, applying a coating process to obtain the desire microwave component. To validate the technique, a difference pattern array of 4×4 horn antennas is designed to operate at mm-wave frequencies. The antenna is based on a complex structure to obtain a difference radiation pattern by rotating twisted section in two different orientations. The prototype is manufactured in a monolithic piece of aluminum alloy AlSi10Mg, providing a single structure that includes both radiating elements and feeding network, including twisters and power dividers in waveguide. The prototype is evaluated in anechoic chamber and planar near-field scanner, obtaining a good agreement with full-wave simulations within the operational bandwidth (34 to 36 GHz). The experimental validation demonstrates that the technique LPBF is a suitable candidate to produce monolithic metal-only microwave components in the Ka band.

Esta comunicación describe las herramientas de software desarrolladas en entorno MATLAB para extraer modelos funcionales para transistores de microondas a partir de medidas reales de RF calibradas (medidas Load-Pull). Estas herramientas permiten extraer modelos lineales y no lineales.

Los modelos lineales están limitados a una sola impedancia y a valores de pequeña señal. Estos modelos son los parámetros S, Y y Z de pequeña señal.

Los modelos no lineales extraídos se basan en los modelos de Cardiff:

modelo A-B convencional, Cardiff filtrado, modelo avanzado de Cardiff y modelo Cardiff suavizado.

Se han diseñados aplicaciones auxiliares para importar datos de medición calibrados y

también para generar gráficos de prueba para evaluar los modelos extraídos.

Finalmente, se ha explorado otro tipo de modelo, basado ​​en redes neuronales artificiales. Otra aplicación MATLAB ha sido diseñada para entrenar redes neuronales superficiales: tipo perceptrón multicapa (MLP), con un nivel oculto.

Para todos los modelos se calcula un factor de mérito consistente en la SNR en dB, obtenida comparando las mediciones (señal deseada) con las predicciones del modelo (señal recibida). Gracias a esto se comprueba que todos los modelos extraídos obtienen buenos resultados para todos y se hace una comparación entre ellos.

This paper presents the design and measurement of a High Power Amplifier (HPA) for Multifunction RF (MFRF) systems. The amplifier have been designed employing Leonardo’s

pHEMT GaN process with 250 nm of gate length (LDO GN25). The amplifier achieves more than 43 dBm of output power with a power added efficiency higher than 20% in the 2-10 GHz frequency band. This HPA is a suitable amplifier to be integrated in the future Transmit and Receive Modules (TRMs) for Active Electronically Scanned Array (AESA) systems that include Radar, Electronic Warfare (EW) and Communications (COMMs) capabilities in the same system.

Pole-Zero Identification has been applied for a large-signal stability-based design of an oscillator for active sensing. The oscillator is formed by a Complementary Split Ring

Resonator (CSRR) and an active feedback. Prototypes has been manufactured to validate the sensing capability when placing different electrically well-known liquids (acetone, methanol and deionized water). Although promising results have been obtained for dielectric characterization given the high frequency selectivity of the oscillator, further work is required to characterize electromagnetic losses.

Small-signal unconditional stability versus load terminations must be evaluated for reliable operation of microwave amplifiers. While extensively studied in 2-port devices, extending stability analysis to N>2 port configurations remains challenging due to the lack of streamlined methodologies. Existing tools often necessitate the use of multiple programs to assess intrinsic stability and unconditional stability, adding complexity to the process. This paper introduces an innovative approach by presenting an all-in-one simulation method for evaluating unconditional stability in 4-port devices using exclusively Advanced Design System (ADS) CAD platform. The Ohtomo’s method implemented through Winslow probes is used to verify the proviso while parametrized S-parameter simulation data are used for calculating the geometrical µ factor. Obtained simulation results are compared with measured data for a 4-port amplifier prototype.

Este trabajo presenta la regresión sparse de modelos de comportamiento basados en la serie de Volterra y predistorsionadores digitales (DPDs) mediante un Stagewise Doubly Orthogonal Matching Pursuit (StDOMP). Se presenta el marco teórico general de las regresiones sparse y se formula el StDOMP aplicando una estrategia por etapas al algoritmo DOMP, i.e., permitiendo que la técnica seleccione un bloque de componentes en cada iteración sin necesidad de realizar una iteración por átomo. La selección por bloques permite reducir la complejidad computacional hasta cierto punto donde se espera que se degraden las prestaciones. Los resultados experimentales destacan el comportamiento de la técnica en la predistorsión de un amplificador de potencia (PA) clase AB trabajando en su régimen no lineal, concluyendo que el StDOMP es capaz de reducir el tiempo de ejecución al mismo tiempo que mantiene el nivel de prestaciones con respecto a DOMP.

Este trabajo aborda el diseño comparativo de dos amplificadores de potencia (APs) de alta eficiencia en banda L, con diferente requerimiento de ancho de banda, para su uso en arquitecturas de transmisión inalámbrica con modulación de la carga. La generalización de las ecuaciones de diseño de un clase E ofrece la flexibilidad para seleccionar la inductancia de polarización del drenador y la red de salida asociada, de modo a cubrir el ancho de banda deseado. Los APs a GaN HEMT implementados, destinados a funcionar en una sola (E5) o dos (E5 y E6) bandas del sistema de navegación Galileo, proporcionan una potencia de salida de alrededor de 40 dBm junto con una eficiencia superior al 75%.

In this paper a novel configuration for ridge gap waveguide (RGW) that allows work at three different frequency bands is presented. The proposed configuration, which uses a

metallized photoresist ridge, lays the groundwork for alternative solutions to address packaging and manufacturing at these frequencies, even the integration of non-lineal devices. Validation through simulation results within the 150-300 GHz and 1-15 GHz

bands confirmed satisfactory performance, featuring a return loss exceeding 15 dB and an insertion loss below 0.2 dB.

En las búsquedas de materia oscura, el factor de calidad de las cavidades de microondas sumergidas en campos magnéticos fuertes desempeña un papel importante en la detección de axiones. Del mismo modo, el factor de forma y el volumen de las cavidades influyen en el rendimiento del haloscopio.

El uso de superconductores de alta temperatura (HTS) puede aumentar considerablemente este factor de calidad, pero los huecos entre las tiras de supercondutores pueden ser perjudiciales. En este estudio, describimos cómo las tapas de la cavidad del superconductor y los huecos entre las tiras HTS (tanto horizontales como verticales) afectan al rendimiento del experimento.

Además, demostramos que modificar la geometría de las capas en una cavidad HTS mejora el factor de calidad, pero esta mejora es compensada por la disminución del factor de volumen y forma, disminuyendo la cifra global de mérito. Además, la existencia de lagunas entre las bandas HTS puede reducir significativamente el factor de calidad. Se indican los límites superiores de estas lagunas.

The aerospace industry has experienced remarkable advances through the adoption of composite materials and 3D technologies, due to their optimal strength-to-weight ratio. However, the extreme temperature gradients of the space environment raise challenges in the behavior of these materials. This paper presents the design and validation of a non-resonant electromagnetic characterization system to evaluate permittivity in dielectric materials at low and high temperatures. Dual microstrip line technology is used in conjunction with the transmission line phase extraction method to measure permittivity over a wide range of frequencies and temperatures, evaluating materials such as FR-4, ROGERS 4350B and CuClad 250. Two types of tests are carried out: one validation test at room temperature and one in the thermal chamber, in a temperature range from -50ºC to 80ºC. Although challenges persist, the system shows consistency and reliability in the measurements, highlighting the significant variation of permittivity with temperature.

In electronics, ferrite core inductors are used to filter and protect electronic equipment against electromagnetic interference (EMI). Therefore, knowledge of the performance of these cores is very important. Their use at high voltage levels can cause their behaviour to change from the linear to non-linear regime, also known as the saturation state in magnetic materials. Under these conditions, the common mode impedance in the power supply and signal lines is modified and the ferrite core inductors do not have the expected characteristics. This paper presents the results of the study of this phenomenon. The test has been carried out by injecting high energy pulses of different amplitudes into a ferrite core inductor until non-linear behaviour can be identified with the saturation state. This study will allow future lines of research on the behaviour of magnetic materials against this kind of pulse of interferences.

En esta contribución se propone una formulación de Ecuaciones Integrales para el análisis de circuitos de microondas basados en la concatenación de diferentes guías de onda rectangulares unidas por una discontinuidad de forma arbitraria. Para ello, se utilizan las funciones de Green según el calibre Lorenz de las guías de onda rectangulares y sus derivadas. Además, se ha empleado el método de Ewald para acelerar significativamente la evaluación de estas funciones de Green de guías de onda rectangulares. En esta contribución, se utiliza una densidad de corriente magnética superficial equivalente definida en la discontinuidad para conectar los problemas equivalentes de cada guía de onda rectangular. El uso de esta densidad de corriente magnética superficial reduce el número de incógnitas en comparación con la ecuación integral del campo eléctrico (EFIE). Además, permite el análisis de dispositivos que son imposibles de modelar directamente con la EFIE. Finalmente, la técnica propuesta ha sido validada por comparación con los resultados proporcionados por software comercial de onda completa como ANSYS HFSS y EFIE, mostrando una buena concordancia y eficiencia numérica.