%0 Journal Article %T Compact Expressions for Efficiency and Bandwidth of Patch Antennas Over Lossy Magneto-Dielectric Materials %+ Pôle Electronique et Systèmes %+ Institut d'Électronique et des Technologies du numéRique (IETR) %A Niamien, Constant %A Collardey, Sylvain %A Sharaiha, Ala %A Mahdjoubi, K. %< avec comité de lecture %@ 1536-1225 %J IEEE Antennas and Wireless Propagation Letters %I Institute of Electrical and Electronics Engineers %V 10 %P 63-66 %8 2011-12 %D 2011 %R 10.1109/LAWP.2011.2107493 %K Substrates %K Bandwidth %K Magnetic resonance imaging %K Microstrip antennas %K Dielectric losses %Z Engineering Sciences [physics]/Electromagnetism %Z Engineering Sciences [physics]/Materials %Z Engineering Sciences [physics]/ElectronicsJournal articles %X Closed-form formulas for calculating the radiation efficiency and bandwidth of patch antennas over lossy magneto-dielectric materials are proposed by using the cavity model. These expressions agree well with simulations. It is well known that the bandwidth of microstrip antennas is enhanced when the dielectric substrate is replaced by a magnetic one. Here, we confirm more generally that not only the bandwidth, but also the radiation efficiency, can be improved when the permeability (μ r ) is greater than the permittivity (ε r ). %G English %L hal-02428426 %U https://hal-normandie-univ.archives-ouvertes.fr/hal-02428426 %~ UNIV-NANTES %~ UNIV-RENNES1 %~ CNRS %~ INSA-RENNES %~ IETR %~ CENTRALESUPELEC %~ COMUE-NORMANDIE %~ UR1-HAL %~ UR1-MATH-STIC %~ UR1-UFR-ISTIC %~ IETR-BEAMS %~ IETR-CUTE %~ IETR-ADH %~ TEST-UR-CSS %~ IRSEEM %~ UNIV-RENNES %~ UNIROUEN %~ INSA-GROUPE %~ ESIGELEC %~ UR1-MATH-NUM %~ IETR-STAR %~ NANTES-UNIVERSITE %~ UNIV-NANTES-AV2022