Open Access
Gaussian beam propagation versus Huygens method in non-paraxial conditions
(1997) Gonzalo García, Ramón; Turullols, Pedro; Río Bocio, Carlos del; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, we present a study about the difference between Gaussian beam propagation and Huygens method to obtain the radiation pattern in the case of non-paraxial conditions. We fix a way to determine the error in the Gaussian beam propagation, in this way, we could know if the approximation is good enough. The computational results show that it is not possible to use the Gaussian propagation equation when we are working with Gaussian beams in non-paraxial conditions.
Open Access
Optimum horn antennas for high order mode beam waveguides
(1995) Río Bocio, Carlos del; Gonzalo García, Ramón; Sorolla Ayza, Mario; Thumm, Manfred; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Higher order free space modes can be considered as serious candidates for power millimeter wave transmission in advanced material processing by using medium power CW gyrotrons. These modes can be propagated in a beam waveguide with properly designed mirrors. Here, we present some optimal ways to excite these higher order free space modes from circular symmetric cylindrical waveguide modes by using optimal non linear horn launchers. An original synthesis procedure is proposed which has been successfully tested by computational simulation.
Open Access
Comparación entre antenas cónicas corrugadas y antenas gaussianas corrugadas
(2002) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, a study of two equal size corrugated horn antennas; a conical and a gaussian profiled horn antenna (GPHA) has been developed. It will be demonstrated that GPHA´s provide lower sidelobes and wider bandwidths, while conical corrugated horn antennas offer higher directivities for the same aperture. Both type of antennas provide low crosspolar levels.
Open Access
Nuevas técnicas para el diseño de antenas de bocina corrugadas
(2004) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The present paper deals with the design of modern corrugated horn antennas for extremely low sidelobe level with the use of the well known corrugated Gaussian Profiled Horn Antenna (corrugated GPHA’s) to improve the radiation pattern features and reduce the antenna size. Basic design rules will be given to start with an appropriate profile which can be quickly used as input profile for modern optimization codes to improve antenna characteristics, i.e. its size.
Open Access
Measurements of a new gaussian profile corrugated horn antenna for millimeter wave applications
(IEEE, 1998) Gonzalo García, Ramón; Martí Canales, J.; Teniente Vallinas, Jorge; Río Bocio, Carlos del; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The measurements results of a new design of corrugated horn antennas [1, 2, 3] following the gaussian expansion are presented in this paper. The performance of two corrugated horn antennas of this kind was verified in the ESTEC Compact Antenna Test Range (CATR) [4]. Very high agreement between measured and predicted results is found.
Open Access
Diseño óptimo de antenas de bocina multimodo para excitar un haz gaussiano fundamental de alta pureza
(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 main idea to design this multimode horn antenna, is to increase the waveguide radius as the desired gaussian mode expands. This principle has also been applied to smooth circular waveguides to excite higher order Gaussian beams from TE0n modes. The horn antenna design considered here, improves the gaussian conversion efficiency, the crosspolarisation and the sidelobes level of some good mixture ( aprox. 85% of TE11 and 15% of TM11 ).
Open Access
Estudio de la posibilidad de utilizar modos de orden superior en guías de onda cuasi-ópticas
(1995) Río Bocio, Carlos del; Gonzalo García, Ramón; Marín Pilz, Miguel; Sorolla Ayza, Mario; Möbius, Arnold; Thumm, Manfred; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The possibility to employ low power gyrotron tubes (10-30 kW, CW) at millimeter wave frequencies (30-100 GHz) has potential applications in advanced ceramic sintering, surface coating, radar, remote sensing, etc.. In materials processing applications, the final shape of the beam is not relevant, because the experiment have to be done in a cavity which has a metallic mode stirrer in order to obtain inside a uniform distribution of the electromagnetic fields. In this paper, we present a preliminar study, showing that it is possible to use high order modes in the transmission line to carry the power to the final experiment efficiently.
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
Generación del modo HE11 a partir de una guía circular lisa monomodo
(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 taper design to obtain the HE11 corrugated circular waveguide mode exciting with a pure TE11 monomode smooth circular waveguide mode. The proposed corrugated taper has a longitudinal section composed of two hyperbolic profiles in series, one concave and the other convex united at a point, such that the derivative is continuous. Superimposed there is an additional tapering of the corrugation depth that goes from l/2 at taper input to l/4 within the first hyperbola. This original synthesis procedure has been successfully tested by computational simulation. The calculation method has been validated by experimental results of other authors.
Open Access
Domain integral equations for electromagnetic band-gap slab simulations
(2004) Hon, B.P. de; Beurden, M.C. van; Gonzalo García, Ramón; Martínez Pascual, Beatriz; Ederra Urzainqui, Íñigo; Río Bocio, Carlos del; Azcona, L.; Alderman, B.; Huggard, P.G.; Maagt, Peter de; Marchand, L.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Electromagnetic band-gap substrates o er advantages regarding cross-coupling in sub-mm range imaging array applications. Electromagnetic scattering by such substrates may e ectively be formulated in terms of integro- di erential equations. The scattered elds are evaluated via the spectral domain in which the 3-D problem reduces to an in nite system of coupled 1-D integro-di erential equations. The associated matrix-vector products are dominated by FFTs. For moderate frequencies an elementary preconditioner in combination with a prudent initial estimate usually su ces to reach rapid convergence using the transpose-free quasi-minimal residual method.