Open Access
Fully metallic Luneburg metalens antenna in gap waveguide technology at V-band
(IEEE, 2023) Pérez Quintana, Dayan; Bilitos, Christos; Ruiz-García, Jorge; Ederra Urzainqui, Íñigo; Teniente Vallinas, Jorge; González-Ovejero, David; Beruete Díaz, Miguel; Institute of Smart Cities - ISC
This article presents the design of a flat Luneburg metalens antenna at V-band using gap waveguide (GW) technology. The metalens consists of a parallel plate waveguide (PPW) loaded with metallic pins whose height is modulated to get an effective refractive index that follows the Luneburg equation. A Groove GW (GGW) H-plane horn is used to illuminate the metalens, such that the rays are collimated and a planar wavefront is generated in the direction of propagation. Since the structure at hand is planar, it can be efficiently integrated on flat surfaces. Moreover, the fully metallic structure is mechanically robust and presents lower losses than lenses including dielectric substrates. A prototype has been fabricated and tested, simulations and experimental results are in very good agreement. The metalens yields an input reflection coefficient (S11) below −10 dB from 45 to 70 GHz, whereas the −3 dB gain fractional bandwidth is 26.2% with respect to a center frequency of 60 GHz, with a peak of 22.5 dB at 61 GHz. These features make this design an interesting solution for millimeter-wave (MMW) applications.
Open Access
Compact antennas in ridge gap waveguide with circular polarization
(IEEE, 2020) Pérez Quintana, Dayan; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper, two compact antennas in Ridge Gap Waveguide (RGW) technology, working at 60 GHz, with a high-purity circular polarization (CP) within a broad bandwidth are manufactured and measured. The antennas are fed from the bottom plane with a WR-15 waveguide (V-band), which couples the wave to the RGW. CP is generated in a simple and effective way, by means of two orthogonal feeder arms that excite a CP in a diamond-shaped slot on top. A broadband matching with reflection coefficient magnitude below -10 dB (S-11 < -10 dB) is achieved from approximately 60.3 to 69.6 GHz (> 9 GHz). Applying the axial ratio criterion (AR < 3dB) the bandwidth in CP is 14.48%, with respect to the central frequency (59 to 70 GHz). The maximum gain in both designs is obtained at 67 GHz, with a value of 5.49 and 11.12 dB respectively.
Open Access
A gap waveguide fed circular polarization antennas in the millimeter wave range
(IEEE, 2020) Pérez Quintana, Dayan; Torres García, Alicia E.; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this work, a novel circular polarization (CP) antennas in ridge gap waveguide (RGW) working in the V-band of the millimeter-wave spectrum is presented. CP is generated in a simple and effective way by means of two orthogonal feeder arms that excite a CP in a rotated square-shaped slot placed on top metallic lid. Parametric simulation studies demonstrate that a difference between both arms length of approximately λ/4 leads to high-purity CP within a relatively broad bandwidth. A square-shaped slot antenna is manufactured and experimentally analyzed. A broadband matching with a reflection coefficient magnitude below -10 dB (S11 <; -10 dB) is achieved from 60.5 to 69.3 GHz. Applying the axial ratio criterion (AR <; 3 dB) the bandwidth in CP is 10.74%, with respect to the central frequency. The maximum gain at broadside is 5.49 dB at 66.8 GHz.
Open Access
Flat lens antenna using gap waveguide technology at millimeter waves
(IEEE, 2021) Pérez Quintana, Dayan; Bilitos, Christos; Ruiz-García, Jorge; González-Ovejero, David; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
In this paper, a flat lens antenna using Gap Waveguide (GW) technology working in the millimeter waves band was designed. The metamaterial lens is fed using a Groove Gap Waveguide (GGW) horn antenna in order to achieve a plane wavefront at broadside. Both devices, metalens and GGW antenna achieve excellent radiation results when combined together. Due to metallic composition, the structure presents more robustness, low loss, and adaptability to a flat surface, able to be used in millimeter wave application.
Open Access
Compact pillbox reflector based on geodesic lens
(IEEE, 2022) Pérez Quintana, Dayan; Chen, Q.; Beruete Díaz, Miguel; Quevedo-Teruel, O.; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
We propose a pillbox antenna in combination with a geodesic lens at 60 GHz. The antenna is implemented in a dual-layer parallel plate waveguide. The waves from a geodesic lens in a first layer, after being reflected by a parabolic mirror connecting the rims of the two layers, enter a second layer and illuminate the radiation aperture. Since the lens produces a virtual focus, the reflector works as if it is fed from that a further location, making the system more compact.
Open Access
Compact bull's-eye antenna in ridge gap waveguide with circular polarization at 60 GHz
(IEEE, 2021) Pérez Quintana, Dayan; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this work, a Bull's-Eye (BE) antenna with circular polarization (CP) based on ridge gap waveguide (RGW) technology, working in the millimeter-wave band (60 GHz) is numerically and experimentally demonstrated. The structure is coupled through a step transition to a ridge-line that ends in two orthogonal arms of different lengths to generate CP. The wave is coupled to the top plate by a central diamond slot surrounded by the BE structure, which consists of four concentric periodic corrugations around the slot. Simulations and experimental results are in good agreement, with practical bandwidth of 6.8% with respect to center frequency and peak gain of 18.4 dB. The antenna has right-handed CP (RHCP) with polarization discrimination of more than 30 dB.
Open Access
Liquid crystals in reconfigurable reflectarray antennas for sub-millimeter waves
(IEEE, 2024-08-21) Pérez Quintana, Dayan; Aguirre Gallego, Erik; Olariaga Jauregui, Eduardo; Kuznetsov, Sergei A.; Lapanik, Valeri I.; Sutormin, Vitaly S.; Zyryanov, Victor Ya; Marcotegui Iturmendi, José Antonio; Beruete Díaz, Miguel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Accelerated technological progress responds to the dynamic evolution of wireless communication systems, fueled by the advent of 5G, the emergence of 6G, and the pervasive integration of the IoT paradigm. Smart antennas play a pivotal role in this advancement, facilitating electronic beam steering to meet escalating demands for enhanced bandwidth and elevated operating frequencies. The spotlight shifts to reconfigurable reflectarray antennas, gaining prominence over conventional phased arrays. Notably, liquid crystals (LCs) emerge as a promising avenue for creating electronically reconfigurable/switchable reflectarrays, specifically tailored for short millimeter and terahertz waves. LCs, as a unique aggregate state combining solid and liquid features, address current technology limitations. Their uniaxial nature and the ability to manipulate molecule orientation enable effective fine-tuning of dielectric permittivity without drawbacks present in existing technologies.
Open Access
Compact groove diamond antenna in gap waveguide technology with broadband circular polarization at millimeter waves
(IEEE, 2020) Pérez Quintana, Dayan; Torres García, Alicia E.; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this paper, three compact antennas using the Ridge Gap Waveguide (RGW) technology working in the millimeter-wave band (60 GHz), with a high-purity and broadband circular polarization (CP) are numerically and experimentally analyzed. The structure is fed from the bottom by means of a standard WR-15 waveguide (V-band) to make it compatible with standard measurement systems. It is coupled with a miniaturized step transition to a ridgeline that ends in two arms of different lengths. CP is generated in a simple and effective way, by means of two orthogonal feeder arms that excite a CP in a diamond-shaped slot on top. Simulations and measurements have an excellent agreement reaching a matching bandwidth (S11 <-10 dB) from 60.3 to 69.6 GHz (> 9 GHz). Applying the axial ratio criterion (AR < 3 dB) the bandwidth in CP is 14.48%, with respect to the central frequency (59 to 70 GHz). The maximum gain is obtained with the most evolved design incorporating a diamond aperture with a horn taper and a circular groove, reaching a value of 11.12 dB at 67.3 GHz.
Open Access
Metal 3D printed D-Band waveguide to surface wave transition
(IEEE, 2020) Freer, Suzanna; Martinez, Rafael; Pérez Quintana, Dayan; Beruete Díaz, Miguel; Hanham, Stephen M.; Attallah, Moataz M.; Navarro Cía, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The coupling efficiency between free space waves and surface waves is low, narrowband, or both. Highly efficient broadband (better than 20% fractional bandwidth) coupling from waveguide modes can be achieved through sophisticated transitions whose fabrication can be enabled through additive manufacturing (e.g. selective laser melting). Here, we present alternative metallic transitions designed to couple the fundamental mode of a D-band waveguide to the fundamental transversemagnetic surface mode supported by a periodic metal corrugated grating. Simulations of the coupling process and initial measurements have been undertaken.
Open Access
Bull’s-eye antenna with circular polarization at millimeter waves based on ridge gap waveguide technology
(IEEE, 2021) Pérez Quintana, Dayan; Ederra Urzainqui, Íñigo; Beruete Díaz, Miguel; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In this communication, a Bull’s-Eye (BE) antenna with circular polarization (CP) based on ridge gap waveguide (RGW) technology is numerically and experimentally demonstrated. The structure is excited from the bottom with a standard WR-15 waveguide (V -band) coupled through a step transition to a ridgeline that ends in two orthogonal arms of different lengths to generate CP. Radiation is coupled to the top plate by a central diamond slot surrounded by the BE structure, which consists of four concentric periodic corrugations around the slot. Simulations and experimental results are in good agreement, with axial ratio below 1 dB at the operation frequency and peak gain of 18.4 dB. The antenna has right-handed CP (RHCP) with polarization discrimination of more than 30 dB.