Title :
A miniaturized rectangular-spiral Bi-band coplanar antenna for off-body communications
Author :
El Hajj, W. ; Person, C. ; Wiart, Joe
Author_Institution :
Lab.-STICC, Whist-Lab., Telecom Bretagne, Brest, France
Abstract :
A new rectangular spiral Bi-band coplanar antenna for off-body communications is presented. This antenna covers two ISM bands, SRD/868 (868-870 MHz) and ISM/2450 (2.4-2.5 GHz). It is considered as electrically small at the lower band, thanks to the specific shape selected. The weak influence of the body on antenna characteristics is described over the two bands using the instantaneous Poynting vectors. The frequency dependence of body characteristics are taken into account over each band. An unexpected phenomenon of efficiency increase with the body proximity in the lower operating band is observed and interpreted. All results are validated through comparative simulations and measurements.
Keywords :
UHF antennas; multifrequency antennas; planar antennas; ISM band; ISM/2450 band; SRD/868 band; biband coplanar antenna; body characteristic; body proximity; electrically small antenna; frequency 2.4 GHz to 2.5 GHz; frequency 868 MHz to 870 MHz; instantaneous Poynting vector; miniaturized coplanar antenna; off-body communications; rectangular coplanar antenna; spiral coplanar antenna; Antenna measurements; Impedance; Reflector antennas; Spirals; Vectors; BAN; Bi-Band Antenna; Body Interaction; Efficiency; Spiral antenna;
Conference_Titel :
Antennas and Propagation (EuCAP), 2013 7th European Conference on
Conference_Location :
Gothenburg
Print_ISBN :
978-1-4673-2187-7
Electronic_ISBN :
978-88-907018-1-8
