Design of a gap waveguide antenna for a 5G repeater at the mmWaves

The rapid expansion of 5G networks demands for the development of advanced antenna systems to enhance signal coverage and reliability. A prominent solution to counteract the unfavourable propagation conditions at the mmWaves are smart repeaters. The antennas in the repeater need to provide high dire...

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Detalles Bibliográficos
Autor: Bock Filella, Roger
Tipo de recurso: tesis de maestría
Fecha de publicación:2024
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/424055
Acceso en línea:https://hdl.handle.net/2117/424055
Access Level:acceso abierto
Palabra clave:Antennas (Electronics)
Millimeter wave devices
Wave guides
5G
mmWaves
smart repeater
gap waveguides
corporate feed network
dispersion diagram
twin slot antenna
grating lobes
cross-polarization
Antenes (Electrònica)
Dispositius d'ones mil·limètriques
Guies d'ones
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Antenes i agrupacions d'antenes
Descripción
Sumario:The rapid expansion of 5G networks demands for the development of advanced antenna systems to enhance signal coverage and reliability. A prominent solution to counteract the unfavourable propagation conditions at the mmWaves are smart repeaters. The antennas in the repeater need to provide high directivity, have a low loss feed, be easy to integrate with electronics and be cost-effective. Gap waveguide (GW) structures have recently been proposed to substitute other types of transmission lines at frequencies in the mmWaves and beyond. They provide some key features such as low transmission loss, broadband performance and a contactless guiding mechanism. In this work, the use of inverted microstrip gap waveguide (IMGW) to implement the corporate feed network (CFN) of an 8 element twin slot array antenna for a GW repeater has been investigated. First, the design of the artificial magnetic conductor (AMC) of the GW structure is carried out. A parametric study of the dimensions of its unit cell has been conducted in order to adjust its dispersion diagram to generate a stopband at the desired frequency range. The impedance, electric field distribution and guided wavelength of the IMGW transmission line have been studied and the losses have been computed from the S-parameter results and compared with microstrip technology. The radiation characteristics of the employed twin slot antenna element are presented and different arrangements of the elements in the antenna array have been analyzed, paying close attention to the appearance of grating lobes and the relative power of the cross-polarization component. A symmetrization technique has been proposed to reduce the latter and the feeding network has been designed in accordance to it. In total three antenna prototypes have been simulated, with different type of linear polarizations: vertical, horizontal and slant 45º. The cross-polarization component in all the prototypes remains under -30 dB. All of them operate between 24.25 GHz and 27.5 GHz and present fan fixed beam radiation patterns with peak gains of at least 14 dB in the broadside and a total efficiency over 80%. The Eigenmode analysis has been performed in CST to extract the dispersion diagrams of the AMC unit cells and HFSS has been employed to extract of the radiation parameters of the antennas. Matlab has been used for post-processing of the results.