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
Reduced loss and prevention of substrate modes with a novel coplanar waveguide based on gap waveguide technology
(MDPI, 2023) Biurrun Quel, Carlos; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
The Gap Waveguide technology utilizes an Artificial Magnetic Conductor (AMC) to prevent the propagation of electromagnetic (EM) waves under certain conditions, resulting in various gap waveguide configurations. In this study, a novel combination of Gap Waveguide technology and the traditional coplanar waveguide (CPW) transmission line is introduced, analyzed, and demonstrated experimentally for the first time. This new line is referred to as GapCPW. Closed-form expressions for its characteristic impedance and effective permittivity are derived using traditional conformal mapping techniques. Eigenmode simulations using finite-element analysis are then performed to assess its low dispersion and loss characteristics. The proposed line demonstrates an effective suppression of the substrate modes in fractional bandwidths up to 90%. In addition, simulations show that a reduction of up to 20% of the dielectric loss can be achieved with respect to the traditional CPW. These features depend on the dimensions of the line. The paper concludes with the fabrication of a prototype and validation of the simulation results in the W band (75–110 GHz).
Open Access
Diseño de alimentadores optimizados para la cámara anecoica de la Universidad de Limoges
(2006) Teniente Vallinas, Jorge; Arnaud, Eric; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, high technology optimized feed horn designs are presented. These feed horns have been designed to improve the quite zone size and behaviour of the CATR of the CREAPE research team at Limoges University. Very nice results are obtained maintaining the quite zone at its maximum size over the whole frequency range with low crosspolar levels and high phase center stability. The designs are very simple and small, resulting in a very low manufacturing cost.
Open Access
Gaussian profiled horn antennas
(1999) Gonzalo García, Ramón; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In many different applications parameters such efficiency, gain, directivity, etc., are really critical. By using the Gaussian techniques presented here, the radiating features of existing horn antenna systems can be improved, only by adding some portion of Gaussian horn antenna at the end or designing a new horn antenna system. In this paper some special features of the Gaussian profiled horn antennas are presented. Furthermore, different design methods based on the Gaussian techniques are analyzed, describing the advantages of these methods versus the existing methods. Some practical examples, comparisons and measurements are also given.
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
Alimentadores gaussianos en guía de onda rectangular
(1999) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A new and efficient design of a rectangular corrugated waveguide mode converter, from TE10 mode in a smooth rectangular monomode waveguide to HE11 mode in a corrugated rectangular waveguide, is proposed. The main idea is the application of Gaussian design techniques, described in the given references, previously applied in circular waveguides. By using these techniques compact and very efficient components are obtained. The obtained far field pattern is rather good as illuminator of square or rectangular parabolic reflectors, with very low sidelobes and crosspolarisation levels, avoiding the use of a rectangular to circular waveguide converter.
Open Access
New approach to the design of corrugated horn antennas
(1997) Gonzalo García, Ramón; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we present two new corrugated horn antenna designs in circular waveguide. The first one is a converter horn antenna from monomode circular waveguide TE11 to corrugated waveguide HE11 mode in a very efficient way. The conversion efficiency varies between 98 % and 99%. The HE11 mode has highly desired radiation pattern characteristics for applications like satellite communications, radar, remote- sensing, etc, nevertheless, when the requirements are more stringent this mode is not good enough and we must look for other solution. This one corresponds to the fundamental gaussian beam, which has outstanding features, such as being a free space mode, having high matching efficiency with a reflector, no sidelobes, perfect symmetry, etc. The second horn antenna presented generates very efficient fundamental gaussian beams at the output (99%-99.9%). It is important to say that the input must look like a gaussian beam, an HE11 for instance, which presents a 98.4% of gaussian beam or similar. We also show a new design in which we are working now, consisting in the junction of the two aforementioned designs. They form an unique horn antenna that results in the TE11 mode, from the fundamental gaussian beam mode. These components have been analysed using the Mode Matching and the Generalised Scattering Matrix techniques and the Moment Method as well as the equations in [1] to get the far field radiation pattern. Our results have been checked against those obtained by other authors.
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
Optimal horn antenna design to excite high purity gaussian beam using overmoded waveguides
(1996) Gonzalo García, Ramón; Río Bocio, Carlos del; Teniente Vallinas, Jorge; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we present an original and optimal multimode horn antenna design to excite the fundamental Gaussian beam from an overmoded waveguide. In particular, we focus the study in overmoded circular corrugated waveguide.The horn antenna design considered here, improves the gaussian conversion efficiency, the cross-polarisation and the sidelobes level of some good mixture (aprox. 85% of TE11 and 15% of TM11).
Open Access
Choked-gaussian corrugated horn antenna design small global coverage horn antenna for TT&C with extremely low sidelobe level
(2003) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Extremely low sidelobe horn antennas are often required for the actual technology. This type of horn antennas are important to avoid interference with other systems. In this paper we describe a new design implementing a radical change in the current technology. It consists in attaching together a choked-waveguide antenna with a classical pure gaussian output corrugated horn. A really impressive radiation pattern with very low sidelobes and crosspolar levels in a very short antenna is obtained. This antenna shape was firstly presented in [1]. In this paper an improvement in size, weight, bandwidth and crosspolar level of the design is shown. This improvement has been possible due to the optimisation of the profile by means of the use of a mode matching code (mwave Wizard) instead of a time consuming finite element code.