Open Access
Con tantos problemas en la Tierra ¿investigar en el espacio? Investigación espacial: un viaje de ida y vuelta
(2013) Gómez Laso, Miguel Ángel; Duque, Pedro; Guglielmi, Marco; Boria Esbert, Vicente; Cortés, Juan Carlos; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Parlamento de Navarra
¿Cómo se justifica la inversión en investigación en el espacio cuando no faltan los problemas en la Tierra? ¿Realmente nos beneficiamos en nuestra vida cotidiana de investigaciones realizadas para resolver cosas que ocurren tan lejos de nosotros? ¿Cuál es o debería ser la postura correcta de nuestros políticos ante la investigación espacial? ¿Se puede hacer investigación espacial en nuestras universidades o es sólo cosa de las grandes Agencias del Espacio? ¿Cuál es el papel que juegan las agencias espaciales, las empresas privadas del sector, los centros de investigación y la administración pública? Durante esta Conversación se tratará de responder a estas preguntas y aclarar por qué la investigación en el espacio es tan relevante y contribuye al progreso económico y social. La charla pretende también subrayar ante la sociedad el valor de la investigación en general y de la investigación espacial en particular.
Open Access
Chirping techniques to maximize the power-handling capability of harmonic waveguide low-pass filters
(IEEE, 2016) Teberio Berdún, Fernando; Arregui Padilla, Iván; Gómez Torrent, Adrián; Arnedo Gil, Israel; Chudzik, Magdalena; Zedler, Michael; Goertz, Franz-Josef; Jost, Rolf; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A novel chirping technique is applied to the design of very high-power waveguide harmonic low-pass filters. The technique could be used, for instance, to avoid multipactor testing in multicarrier systems such as the output multiplexer of a communications satellite. The novel chirped filter shows low insertion loss, all higher order mode suppression, and broad stopband rejection up to the third harmonic. This paper focuses on the maximization of the filter power-handling capability without affecting its excellent frequency behavior. Given a certain frequency response, the E-plane mechanical gap of the structure and the length (in the propagation direction) of the waveguide sections between its constituent bandstop elements can be considered to improve the high-power behavior. However, the power performance may not be sufficient yet in some applications if we wish, for instance, multipactor testing to be avoided. This becomes feasible by chirping the length (in the propagation direction) of the bandstop elements. An example for Ku band is discussed for relevant frequency specifications. An improvement from ∼8 kW (non-chirped filter) to more than 100 kW (chirped filter) is obtained. As a reference, the equivalent waffle-iron filter can handle only 0.15 kW. Such high-power threshold levels have never been reported before for such kind of filters.
Open Access
Rectangular waveguide filters with meandered topology
(IEEE, 2018) Teberio Berdún, Fernando; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arnedo Gil, Israel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2017-000130
In this paper, a new topology for rectangular waveguide bandpass and low-pass filters is presented. A simple, accurate, and robust design technique for these novel meandered waveguide filters is provided. The proposed filters employ a concatenation of ±90° E-plane mitered bends (±90° EMBs) with different heights and lengths, whose dimensions are consecutively and independently calculated. Each ±90° EMB satisfies a local target reflection coefficient along the device so that they can be calculated separately. The novel structures allow drastically reduce the total length of the filters and embed bends if desired, or even to provide routing capabilities. Furthermore, the new meandered topology allows the introduction of transmission zeros above the passband of the low-pass filter, which can be controlled by the free parameters of the ±90° EMBs. A bandpass and a low-pass filter with meandered topology have been designed following the proposed novel technique. Measurements of the manufactured prototypes are also included to validate the novel topology and design technique, achieving excellent agreement with the simulation results.
Open Access
Design procedure for new compact waffle-iron ilters with transmission zeros
(IEEE, 2018) Teberio Berdún, Fernando; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arnedo Gil, Israel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a novel waffle-iron filter with transmission zeros at multiple frequencies, along with its design procedure, is presented. The proposed filter features a high-power behavior and a wide rejected band in a single compact structure by means of a set of transmission zeros that can also be placed close to the passband. Its design method rests on a divide-and-rule strategy, where the physical dimensions of the constituent design entities (DEs) can be easily computed in a very short time. A novel high-power compact waffle-iron filter with transmission zeros at multiple frequencies has been designed as well as several classical waffle-iron filters with transmission zeros at one frequency only, using a detailed step-by-step procedure which avoids the bruteforce optimizations needed until now. Multipactor and corona simulations have been conducted proving a high-power handling capability of 1.8 kW and 78.6 W, respectively. A prototype of the novel filter has been fabricated, obtaining a remarkable accordance between the simulated and measured results.
Open Access
Producing and exploiting simultaneously the forward and backward coupling in EBG-assisted microstrip coupled lines
(IEEE, 2016) Percaz Ciriza, Jon Mikel; Chudzik, Magdalena; Arnedo Gil, Israel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a methodology is proposed for the design of EBG-assisted coupled line structures in microstrip technology, controlling independently the forward and backward coupling. It is based on the use of a single-frequency-tuned electromagnetic bandgap (EBG) structure to produce a single backward-coupled frequency band, in combination with the forward-coupled frequency bands produced by the difference between the even and odd mode propagation constants present in microstrip technology. Thus, the central frequency of the backward-coupled band is controlled by the period of the EBG structure, while the frequencies of the forward coupled bands are fixed by the length of the device. The rest of the frequencies go to the direct port giving rise to a device with the input port matched at all the frequencies and where the coupled bands are easily controllable by adjusting the corresponding design parameter. The novel methodology proposed has been successfully demonstrated by designing a triplexer intended for the GSM (900 MHz) and WLAN (2.4 GHz and 5.5 GHz) telecommunication bands.
Open Access
Planar magnetoinductive wave transducers: theory and applications
(AIP Publishing, 2004) Freire, M. J.; Marqués, R.; Medina, Francisco; Gómez Laso, Miguel Ángel; Martín, F.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Transduction of magnetoinductive waves (MIWs) in planar technology is demonstrated. A transducer consisting of a one-dimensional periodic array of metallic split squared ring resonators (SSRR), placed between a pair of microstrip lines on a planar substrate has been fabricated and measured. The microstrip lines are inductively coupled to the SSRRs located at the ends of the periodic array and excite MIWs that propagate along the array. The theoretical model for the dispersion of MIWs is used to predict the dispersion relation and the delay time in the device. The delay time was measured and a good agreement was found with the theoretical predictions. The transmission coefficient of the device was also measured. The theoretical and experimental results suggest that the proposed configuration can find application in the design of delay lines and other microwave devices. In fact, the behavior of the proposed transducer is similar to that of the conventional ferrite magnetostatic-wave transducer. However, ferrite devices are fragile, difficult to integrate, and require a heavy external magnet or electromagnet to magnetize the ferrite to saturation. Since all these drawbacks are not present in the proposed configuration, it may be a useful alternative to those devices for many practical applications.
Open Access
Synthesis of one dimensional electromagnetic bandgap structures with fully controlled parameters
(IEEE, 2017) Arnedo Gil, Israel; Chudzik, Magdalena; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Teberio Berdún, Fernando; Benito Pertusa, David; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we propose a novel synthesis strategy for the design of one dimensional electromagnetic bandgap (1- D-EBG) structures where all the performance parameters of these devices can fully be controlled, i.e., the central frequency of the forbidden band, its attenuation level and bandwidth, and the ripple level at the passbands. The novel synthesis strategy employs a new inverse-scattering technique to accurately synthesize the 1-D-EBG structure, targeting a properly interpolated version of a classical periodic filter fulfilling the required frequency specifications. The new inverse-scattering technique follows a continuous layer peeling approach and relies on the coupled-mode theory to precisely model the microwave structures. Telecommunication and radar systems, as well as material characterization devices, will be profited by this proposal with which enhanced filters, sensors, power dividers, couplers, mixers, oscillators, and amplifiers can be designed in many different technologies. As a proof of concept, a 1-D-EBG structure in microstrip technology with a single forbidden band (free of spurious stopband replicas), with attenuation level of 30 dB, fractional bandwidth larger than 100%, and return loss level at the passbands of 20 dB, has been designed and fabricated. The measurements obtained are in very good agreement with the simulations and target specifications, being free of spurious replicas up to the 15th harmonic, showing the robustness and very good performance of the novel design strategy proposed.
Open Access
Passive microwave component design using inverse scattering: theory and applications
(Hindawi, 2013) Arnedo Gil, Israel; Arregui Padilla, Iván; Chudzik, Magdalena; Teberio Berdún, Fernando; Lujambio Genua, Aintzane; Benito Pertusa, David; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We briefly review different synthesis techniques for the design of passive microwave components with arbitrary frequency response, developed by our group during the last decade. We provide the theoretical foundations based on inverse scattering and coupledmode theory as well as several applications where the devices designed following those techniques have been successfully tested. The main characteristics of these synthesis methods are as follows. (a) They are direct, because it is not necessary to use lumpedelement circuit models; just the target frequency response is the starting point. (b)They are exact, as there is neither spurious bands nor degradation in the frequency response; hence, there is no bandwidth limitation. (c) They are flexible, because they are valid for any causal, stable, and passive transfer function; only inviolable physical principles must be guaranteed. A myriad of examples has been presented by our group in many different technologies for very relevant applications such as harmonic control of amplifiers, directional couplerwith enhanced directivity and coupling, transmission-type dispersive delay lines for phase engineering, compact design of high-power spurious free low-pass waveguide filters for satellite payloads, pulse shapers for advanced UWB radar and communications and for novel breast cancer detection systems, transmission-type Nth-order differentiators for tunable pulse generation, and a robust filter design tool.
Open Access
Arrangements of via-holes in microstrip lines as metallodielectric periodic structures
(Wiley, 2000) Gómez Laso, Miguel Ángel; Lopetegui Beregaña, José María; Bacaicoa, Miguel; Hernández, Jorge; Gonzalo García, Ramón; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
In this paper, the use of via holes in microstrip lines to design periodic structures that can be regarded as metallodielectric electromagnetic crystals is analyzed. The proposed novel periodic structures achieve a notably increased reflectivity compared to that obtained with a single via hole. Theoretical analysis and experimental results are provided showing a satisfactory performance for these devices as broadband reflectors or short circuits with enhanced behavior at high frequencies.
Open Access
Routing with classical corrugated waveguide low-pass filters with embedded bends
(EMW Publishing, 2018) Teberio Berdún, Fernando; Percaz Ciriza, Jon Mikel; Arregui Padilla, Iván; Martín Iglesias, Petronilo; Lopetegui Beregaña, José María; Gómez Laso, Miguel Ángel; Arnedo Gil, Israel; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A very simple design method to embed routing capabilities in classical corrugated filters is presented in this paper. The method is based on the calculation of the heights and lengths of the so-called filters design building blocks, by means of a consecutive and separate extraction of their local reflection coefficients along the device. The proposed technique is proved with a 17th-order Zolotarev filter whose topology is bent twice so that the input and output ports are in the same plane while preserving the in-line filters behaviour. This new filter allows the possibility of eliminating subsequent bending structures, reducing the insertion loss, weight, and PIM.