Open Access
Reduction of phase shifters in planar phased arrays using novel random subarray techniques
(MDPI, 2024-07-06) Valle, Juan L.; Panduro, Marco A.; Río Bocio, Carlos del; Brizuela, Carlos A.; Covarrubias, David H.; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza
Reducing the number of phase shifters by grouping antenna elements into subarrays has been extensively studied for decades. The number of phase shifters directly affects the cost, complexity, and power consumption of the system. A novel method for the design of phased planar antenna arrays is presented in this work in order to perform a reduction of up to 70%70% in the number of phase shifters used by the array, while maintaining the desired radiation characteristics. This method consists of creating fusions of subarrays to generate random sequences that form the best feeding network configuration for planar phased arrays. The obtained solution allows scanning the mainlobe at 𝜃=−40∘θ=−40∘ elevation with a range of scanning of [−75∘<𝜙<75∘][−75∘<ϕ<75∘] in the azimuth plane, while maintaining a side lobe level below −10−10 dB and achieving a reduction of 62%62% in the number of phase shifters. It is shown that each solution is created based on search criteria, which influence the morphology of the array in terms of subarray size and orientation. The proposed methodology shows great flexibility for creating new phased antenna array designs that meet the requirements of specific applications in a short period of time.
Open Access
An innovative way of using coherently radiating periodic structures for phased arrays with reduced number of phase shifters
(IEEE, 2021) Juárez, Elizvan; Panduro, Marco A.; Covarrubias, David H.; Reyna, Alberto; Sánchez, Brian; Río Bocio, Carlos del; Institute of Smart Cities - ISC
This article presents an innovative design technique for feeding phase antenna arrays using coherently radiating periodic structure (CORPS) technology for reducing the number of phase shifters (PSs) in limited-scan applications with low sidelobe level (SLL). The proposed configuration is implemented taking advantage of the phase interpolation property of a CORPS network of one layer. This configuration is built by interconnecting 2×3 CORPS networks in a strategic way in order to provide a reduction in the number of PSs while maintaining the scanning capability. Experimental results and full-wave simulations based on CST Microwave Studio reveal that the proposed design technique reduces the recombination losses and generates a better phase slope with respect to the basic CORPS network providing a reduction in the number of PSs. As a novel contribution, this article provides the full antenna system design in order to analyze and study the PSs reduction performance and scanning capabilities of the proposed technique to feed linear antenna arrays. The proposed design technique provides a reduction in the number of PSs for a scanning range of ±25° in linear arrays. The array design model includes the application of the raised cosine amplitude distribution to generate a radiation pattern with minimum SLL. The linear array system was validated by experimental measurements of the full system prototype and full-wave simulations results are provided to verify the accuracy of the array model and to take mutual coupling into account. The proposed case provides a good design compromise with respect to other cases in the state of the art.
Open Access
Resolution capabilities of future THz cameras
(2010) Lizarraga Cubillos, Juan Camilo; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
THz technology for developing imaging systems has recently aroused great interest, mainly due to the large number of applications in which these frequencies can be used: security, vision in hard environments, etc. In this paper we propose a method that reduces significantly the number of detectors needed for achieving certain resolution by means of diffraction that paradoxically is its main limiting factor in current imaging devices. The method uses diffraction as a way of achieving spatial diversity and as an anti-aliasing LPF. Decimation is used to reduce the number of detectors.
Open Access
Diseño de una antena dual gaussiana de doble profundidad de corrugación
(2003) Ortiz Pérez de Eulate, Noelia; Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper a new design of a dual-band corrugated horn antenna is presented. The design is based on a gaussian profile to allow high pattern symmetry, low-crosspolar levels and low-side-lobes over a wide frequency range. To achieve a dual-band corrugated horn antenna, dual depth corrugations were used along the whole profile. The design presents a nice far field radiation pattern, which is compatible with the frequency reuse requirements in satellite communication antennas. The horn has been designed to operate in two frequency bands between X, Ku and K bands. Simulations and measurements show pretty good radiation patterns with return loss below –20dB and crosspolar-levels below –30dB in both frequency bands.
Open Access
Coherently radiating periodic structures (CORPS): aplicaciones prácticas
(2005) Ibáñez Loinaz, Asier; Betancourt Quiñones, Diego; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper some possible applications of the new philosophy to design antenna systems based on the Coherently Radiating Periodic Structures (CORPS) is presented. This principle could allow the designer to simplify the needed feeding network for many array antenna systems since some elements could be coupled from the neighbouring ones, keeping the original excitation profile. It will be also shown in this paper how the three dimensional version of CORPS could be understood as a focusing planar lens, since it is possible to distribute the information of one element to many radiating elements by using the coherent coupling mechanism between all the elements of the whole structure. With this configuration, many directive beams could be really close to each other, increasing the possibilities to handle high resolution in imaging systems.
Open Access
Design of concentric ring antenna arrays for isoflux radiation in GEO satellites
(Institute of Electronics, Information and Communication Engineers (IEICE), 2011) Reyna, Alberto; Panduro, Marco A.; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The design of concentric rings arrays for isoflux radiation is reported in this paper. This design considers the reduction of the side lobe level and the isoflux radiation requirements for Geostationary Earth Orbit (GEO) satellites. The optimization problem considers the spacing between rings and the levels of amplitude excitations. The well-known method of Particle Swarm Optimization (PSO) is utilized for the optimization. The obtained results could lead the satellite hardware to be reduced significantly even more than results presented previously in the literature.
Open Access
Design and characterization of terahertz CORPS beam forming networks
(Springer, 2023) Biurrun Quel, Carlos; Haddad, Thomas; Sievert, Benedikt; Kress, Robin; Weimann, Nils; Erni, Daniel; Rennings, Andreas; Stöhr, Andreas; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
This work reviews the design and applicability of beam-forming networks based on Coherently Radiating Periodic Structures (CORPS-BFN) at Terahertz (THz) frequency bands. These versatile networks offer two operation modes: a continuous beam steering – feeding an antenna array with a linearly progressive phase distribution – using a reduced number of phase controls; or a multi-beam operation, generating independent, overlapped beams. These networks are built upon the concatenation of power combiners/dividers (PCDs) with isolated outputs. The isolation is provided by monolithically integrated resistors, implemented with Ti/TiO thin films for the first time. In this work, a planar prototype of a (inputs/outputs) microstrip CORPS-BFN for operation in the WR3.4/WM-864 band (220–330 GHz) on a thin 50 m Indium Phosphide (InP) substrate is designed, fabricated, and characterized. The measured S-parameters show a reflection coefficient better than -15 dB and an insertion loss between 1.6 and 3.2 dB in the whole band. In addition, an isolation better than 20 dB between the input ports has been measured. An overall remarkable agreement is observed between the measurements and the simulations. Last, the applications, scalability and efficiency of this type of networks at the targeted band are discussed in detail.
Open Access
Freehand system for antenna diagnosis based on amplitude-only data
(IEEE, 2021) Álvarez Narciandi, Guillermo; Laviada, Jaime; Álvarez López, Yuri; Ducournau, Guillaume; Luxe, Cyril; Belem Goncalves, Cybelle; Gianesello, Frederic; Nachabe, Nour; Río Bocio, Carlos del; Las-Heras, Fernando; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This article presents a portable system for freehand antenna diagnosis and characterization based on amplitude-only data. The amplitude-only samples are acquired by moving a handheld probe, which is tracked by a motion capture system, in front of the antenna under test (AUT) aperture. The acquired measurements are processed using the phaseless sources reconstruction method to compute an equivalent current distribution on the AUT aperture. Finally, the radiation pattern of the AUT can be obtained by evaluating the corresponding radiation integrals. Unlike previous work, the use of amplitude-only data avoids the need of a phase reference, paving the way to the diagnosis and characterization of antennas under operational conditions. This fact, together with the handheld capabilities, makes the system very convenient for measurements of already deployed and onboard antennas. Moreover, these amplitude-only acquisitions also simplify the required hardware. The system has been validated through measurements in a wide frequency range from Ka-band up to 300 GHz. Despite that one cannot expect the same degree of accuracy that can be achieved under laboratory conditions (including an anechoic environment and highly accurate positioners), the system shows excellent capabilities to detect malfunctions, such as wrong amplitude/phase distributions, as well as a fair estimation of the far field.
Open Access
Synthesis of volumetric ring antenna array for terrestrial coverage pattern
(Hindawi, 2014) Reyna, Alberto; Panduro, Marco A.; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X -Y, the positions of the rings on the plane X -Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction.
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.