Study and fabrication of a microwave circulator with magnetic nanoparticles oriented in the 40-60 GHz range
type: Dataset
description: Microwave passive components become increasingly commercialized and used in telecommunications systems. Technological growth and the increased demand for new applications require higher performance and lower costs. In wireless applications, especially in "transceivers", circulators are used for transmitting and receiving signals simultaneously using a single antenna. Magnetic layers traditionally deposited and integrated require a high crystallization temperature and the application of an external magnetic field to keep the orientation of magnetic moments. This orientation is however obtained by heavy and bulky magnets. Given these technological limitations and the need to miniaturize, the use of barium hexaferrite particles envisages the development of self-biased and miniaturized circulators having magnetic composite materials. The ambition of this work is to study and to fabricate a microwave circulator with magnetic nanoparticles oriented in the 40 - 60 GHz range. The state of the art describes various topologies coplanar circulators from which the coplanar topology is chosen for our application. The analytical study is based on Bosma’s work to model the stripline circulator. The main geometric dimensions obtained are then transposed to the coplanar structure using the 3D simulation tool HFSS. Faced with this tool’s limitations, different structures were studied and simulated numerically to shape the best the composite material. Several series of prototypes are then manufactured. The magnetic composite material was deposited in layers having thicknesses of 40 and 100 μm. The microwave characterizations show the performance of the fabricated device. Research tracks are proposed to improve the performance of our prototypes
identifier: NNT: 2011STET4012
issued: 2026-05-18T22:22:27.437989
language: fr
modified: 2026-05-18T22:22:27.437995
contact point: Organization
  fn: CCSD
keyword: barium-hexaferrite-nanoparticles
keyword: caracterisation-hyperfrequences
keyword: circulateur-coplanaire
keyword: composants-passifs
keyword: coplanar-circulator
keyword: ferrite
keyword: infoeu-reposemanticsdoctoralthesis
keyword: magnetic-nanocomposite
keyword: microwave-characterization
keyword: nanocomposite-magnetique
keyword: nanoparticules-dhexaferrite-de-baryum
keyword: passive-components
keyword: spiotherengineering-sciences-physicsother
keyword: su-8
keyword: theses
landing page: https://theses.hal.science/tel-00670799

Study and fabrication of a microwave circulator with magnetic nanoparticles oriented in the 40-60 GHz range
type: Distribution
format: HTML
issued: 2026-05-18T22:22:27.528566
modified: 2026-05-18T22:22:27.391473
access URL: https://theses.hal.science/tel-00670799

test_moissonnage_selune
type: Agent