title: Characteristics of microstrip muscle-loaded single-arm Archimedean spiral antennas as investigated by FDTD numerical computations.
abstract: The radiation characteristics and mode of operation of single-arm, groundplane backed, Archimedean spiral antennas are investigated by means of conformal finite difference time domain numerical analysis. It is shown that this antenna type may be categorized as a well-matched, broadband, circularly polarized traveling wave structure that can be fed directly by nonbalanced coaxial networks. The study further concentrates on relevant design and description features parameterized in terms of measures like radiation efficiency, sensing depth, directivity, and axial ratio of complementary polarizations. We document that an antenna of only 30-mm transverse size produces circularly polarized waves in a two-octave frequency span (2-8 GHz) with acceptable radiation efficiency (76%-94%) when loaded by muscle-like tissue.
authors.affiliation: Electrical Engineering Group, Institute of Physics, Faculty of Science, University of Tromsø, N-9037 Tromsø, Norway. Svein.Jacobsen@phys.uit.no
authors.forename: Svein
authors.initials: S
authors.lastname: Jacobsen
authors.forename: Hans Olav
authors.initials: HO
authors.lastname: Rolfsnes
authors.forename: Paul R
authors.initials: PR
authors.lastname: Stauffer
mesh_terms: D000818:Animals; D003198:Computer Simulation; D017076:Computer-Aided Design; D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods; D008872:Microwaves / Q000627:therapeutic use*; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000502:physiology* / Q000528:radiation effects*; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*