Open Access
Hexagonal CORPS-BFN to feed OLAF SAR instrument
(IEEE, 2021) Biurrun Quel, Carlos; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Río Bocio, Carlos del; Institute of Smart Cities - ISC
The concept of Coherently Radiating Periodic Structures-based Beam Forming Networks is applied to feed OLAF (OverLapped SubArray Fed) antenna for SAR Instrument at L-Band. The proper feeding of this system requires the multiple beams to be highly overlapped, and that is generated by a CORPS-BFN using a new 4-port Gysel power combiner/divider implemented in a suspended stripline technology. The network provides high isolation between inputs/outputs, low insertion loss, great return loss and the desired ovelapping of the different beams.
Open Access
Feeder system design for OLAF SAR instrument
(IEEE, 2022-04-11) Biurrun Quel, Carlos; García-García, Quiterio; Río Bocio, Carlos del; Institute of Smart Cities - ISC
The design of the feeding system for the focal array in OLAF (Over-Lapped Sub-Array Fed) antenna for SAR Instrument at L-Band is presented. The proposed design consists of a circular patch with a balanced excitation all of it embedded in a ground plane which is connected to the lower ground plane by some shorting pins, reducing the mutual coupling with the neighbour radiating elements of the focal array. The balanced excitation has been implemented with a 180° hybrid using the differential input port. Dual polarization is achieved by using two 180° hybrids within the same layer. The stringent requirements for the system, namely low in cross-polarization, high isolation between the two polarizations (both below the-25dB reference level) and azimuthal symmetry of the radiation pattern are fulfilled within all the working bandwidth.
Open Access
Development of a microscopic driver-centric simulator with Unity3D and SUMO
(2016) Biurrun Quel, Carlos; Serrano Arriezu, Luis Javier; Olaverri Monreal, Cristina; Escuela Técnica Superior de Ingenieros Industriales y de Telecomunicación; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola Teknikoa; University of Applied Sciences Technikum Wien (Austria)
Diversas herramientas han sido desarrolladas en el campo de la simulación de tráfico. Estas herramientas permiten recrear situaciones de tráfico complejas de una forma realista, que pueden ser empleadas en la planificación de sistemas de transporte o para evaluar comunicaciones V2V (Vehículo a vehículo) en situaciones reales de tráfico. A pesar de que ciertos trabajos han sido llevados a cabo en el campo de la representación 3D de las simulaciones de tráfico, no existen demasiados ejemplos de plataformas Driver-Centric (con perspectiva del conductor) en los que el comportamiento del resto de vehículos es modelado por un simulador de tráfico. En este Trabajo Fin de Grado se presenta la elaboración de un simulador de tráfico Driver-Centric, capaz de emplear redes de carreteras reales junto con modelos de tráfico realistas, en un escenario 3D. Una librería existente en Java ha sido traducida a .NET y usada en Unity3D para implementar el protocolo TraCI y lograr la comunicación con el programa de simulación microscópica de tráfico, SUMO. Finalmente, se ha evaluado el funcionamiento del simulador y se han presentado futuras líneas de trabajo.
Open Access
Multi-channel feedarray reflector antenna based radar concept for HRWS SAR imaging
(IEEE, 2021) Castillo, Javier del; Orgaz, Lara; García, Quiterio; Memeletzoglou, Nafsika; Toso, Giovanni; Imbembo, Ernesto; Biurrun Quel, Carlos; Río Bocio, Carlos del; Institute of Smart Cities - ISC
Large deployable reflector based multi-channel antenna systems are a key component of next generation SAR missions as they allow implementing multi-beam imaging capabilities and provide an efficient way to overcome the classical SAR resolution-coverage trade-off, covering wide swaths with high azimuth resolution. The presented work shows the design of a multichannel L-band SAR system and antenna architecture based on different feeders concepts and capable to map 400 km ground swath with 5 meter spatial resolution in dual polarization. The paper describes a preliminary design and architecture of the SAR system and the antenna where different design aspects including beamforming concepts and feedarray implementation techniques have been identified and assessed in view of achieving the required SAR performances while reducing the overall complexity of the solution.
Open Access
Impedance modelling for high frequency unitraveling-carrier photodiodes
(IEEE, 2021) Grzeslo, Marcel; Biurrun Quel, Carlos; Stöhr, Andreas; Institute of Smart Cities - ISC
High-speed photodiodes stand out as potential candidates to enable next-generation communication systems working as mmWave/THz sources due to their intrinsic broadband behaviour. Impedance matching is an essential task in microwave engineering that enables an efficient delivery of the power generated by the source (i.e. photodiode) to the load (i.e. antenna). In this work, we analyse the impedance of a generic uni-travelling carrier photodiode and its dependency with frequency, bias voltage and other operational parameters. In addition, we present some calculations and use cases, highlighting the importance of properly matching this impedance in an actual system.
Open Access
Photonic-assisted 2-D terahertz beam steering enabled by a LWA array monolithically integrated with a BFN
(Optica, 2022) Haddad, Thomas; Biurrun Quel, Carlos; Lu, Peng; Tebart, Jonas; Sievert, Benedikt; Makhlouf, Sumer; Grzeslo, Marcel; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Stöhr, Andreas; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
A novel photonic-assisted 2-D Terahertz beam steering chip using only two tuning elements is presented. The chip is based on an array of three leaky wave antennas (LWAs) with a monolithically integrated beamforming network (BFN) on a 50 µm-thick indium phosphide substrate. The THz beam angle in elevation (E-plane) is controlled via optical frequency tuning using a tunable dual-wavelength laser. An optical delay line is used for azimuth (H-plane) beam control. The simulated beam scanning range is 92° in elevation for a frequency sweep from 0.23 THz to 0.33 THz and 69.18° in azimuth for a time delay of 3.6 ps. For the frequency range from 0.26 THz to 0.32 THz, it is confirmed experimentally that the THz beam scans from −12° to +33°, which is in good agreement with the numerical simulations. The beam direction in azimuth scans with a total angle of 39° when applying a delay difference of 1.68 ps. A good agreement is found between theoretically predicted and experimentally determined THz beam angles with a maximum angle deviation below 5°. The experimental scanning angles are limited due to the mechanical constraints of the on-wafer probes, the on-chip integrated transition and the bandwidth of the THz receiver LNA. The mechanical limitation will be overcome when using a packaged chip.
Open Access
New hexagonal CORPS-BFN for multibeam antenna applications
(IEEE, 2020) Biurrun Quel, Carlos; Montesano, Antonio; Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Río Bocio, Carlos del; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This work presents a new topology of a Coherently Radiating Periodic Structure - Beam Forming Network (CORPS-BFN) and its application for multibeam systems. A unit cell, consisting of a transition from a coaxial input to an intersection of three strip-lines with an angular span of 120 degrees, is proposed and analysed. A periodical replication of the cell gives rise to a uniform layer, allowing a proper matching of the ports of the network. Stacked layers allow in-phase propagation and distribution of the energy through the structure, increasing the number of output ports with each layer.
Open Access
Noise in coherently radiating periodic structures beam forming networks
(IEEE, 2022) Biurrun Quel, Carlos; Río Bocio, Carlos del; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Following the noise wave theory, beam forming networks based on Coherently Radiating Periodic Structures (CORPS-BFN) are analysed and proven to be capable of enhancing the Signal to Noise Ratio of the system by analogically multiplexing the signal and noise contributions present at every input port. The geometry of the network determines the maximum enhancement achievable, which is demonstrated to be independent from insertion losses. These findings are supported by a mathematical approach, as well as with experimental data.
Open Access
Characterization of 3D-printed choke horn antenna for 5G backhaul applications
(IEEE, 2019) Biurrun Quel, Carlos; Lacombe, Elsa; Gianesello, Frederic; Luxe, Cyril; Río Bocio, Carlos del; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The 200 and 320 GHz frequency band constitutes an interesting window with approximately constant attenuation, which could potentially have applications in the area of ultrahigh-capacity wireless links. The user's demand of data for future 5G mobile systems will require backhaul systems to be able to provide several dozens of GHz in order to satisfy those demands. Furthermore, additive manufacturing techniques stand as an interesting way of reducing costs without sacrificing performance. In this work, a choke horn antenna, designed at a central frequency of 240 GHz and manufactured by 3D-printing technology is presented. This antenna is thought to serve as the feed of a compact parabolic reflector. The antenna has been measured by Near- and Far-Field techniques and these measurements show an adequate agreement with simulation results. Additionally, the measurement set-up included a novel dynamic time-domain, software-controlled gating that readjusts itself for every measured point.
Open Access
Evaluating noise in passive beam forming networks for multibeam applications
(Elsevier, 2023) Biurrun Quel, Carlos; Río Bocio, Carlos del; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this work, we identify that the analysis in terms of noise of multibeam passive beam forming networks requires a proper formulation, in order not to overestimate the noise generated by the network. We show that the inherent spatial diversity offered by this type of networks results in an improvement of the SNR, similar to the one obtained by digital architectures, with a penalty due to the insertion loss. To illustrate this phenomena, two generalized equivalent circuits are proposed are a numerical example is presented.