Novel modelling techniques for Waveguide Antenna Feeders and its application to micro/millimeter-Wave Antenna Design

• Autores: Lucas Polo López
• Directores de la Tesis: Jorge Alfonso Ruiz Cruz (dir. tes.), Juan Corcoles Ortega (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2020
• Idioma: inglés
• Títulos paralelos:
  • Nuevas técnicas de modelado para alimentadores de antena en guía de onda y su aplicación al diseño de antenas de microondas y milimétricas
• Tribunal Calificador de la Tesis: Mauro Ettorre (presid.), José Luis Masa-Campos (secret.), Jesús Rubio Ruiz (voc.)
• Programa de doctorado: Programa de Doctorado en Ingeniería Informática y de Telecomunicación por la Universidad Autónoma de Madrid
• Materias:
  • Ciencias tecnológicas
    • Tecnología electrónica
      • Antenas
      • Dispositivos de microondas
• Enlaces
  • Tesis en acceso abierto en: Biblos-e Archivo
• Resumen

  • This thesis is framed in the context of advanced waveguide antenna feeders. More specifically, it is devoted to the development of modelling techniques that can be applied in the design of new antenna systems, either to increase the performance of already known antennas or to create designs with completely novel characteristics.

    To achieve this goal, the thesis is divided into three main parts: 1) computation of the radiation pattern produced by radiating apertures and radiation pattern synthesis in apertures, 2) quasi-analytical horn antenna simulation and its application to horn antenna design, and 3) innovation in other non-radiating devices used in antenna feeders.

    The two pillars that sustain the modelling ideas presented in this thesis are the radiating aperture field equivalence principle, which relates the aperture electromagnetic field distribution to the far-zone radiated field, and the waveguide modal field expansion, which allows to express any aperture field distribution as a weighted summation of modal field functions. Thanks to the combination of these two concepts, the total radiation pattern produced by the aperture can be expressed as the weighted summation of the radiation patterns corresponding to each of the modal field functions that exist in a waveguide with the same cross-section as the aperture. One application of this analysis approach is the synthesis of an aperture field distribution that generates a radiation pattern with certain specified characteristics, including the specific case of monopulse difference patterns.

    This radiation pattern calculation strategy can also be used for the fast analysis of horn antennas. The mode-matching method is a waveguide device analysis technique well-known for providing accurate results and being computationally efficient. By a mode-matching analysis of the horn profile it is possible to determine the electromagnetic field distribution at the horn aperture, from which the radiation pattern produced by the horn antenna can be obtained. The accuracy of this analysis strategy is comparable to that achieved by general purpose numerical tools, but the computation time is significantly reduced. Therefore, this mode-matching analysis can be efficiently integrated with an optimization routine in order to tune the design parameters of a horn profile. To show the usefulness of this optimization scheme a sophisticated W frequency band monopulse horn feed with a triple radiation pattern is designed.

    Finally, the design of two innovative waveguide devices is presented: a reconfigurable phase shifter completely implemented in waveguide technology and a compact circular polarizer. Although they are not directly responsible for radiating or receiving electromagnetic waves, these devices also play a key role in the feed chain of many wireless applications like radar, phased arrays or satellite communications among others.