Title :
Microstrip patch designs which do not excite surface waves
Author :
Bhattacharyya, A.K. ; Jackson, D.R. ; Williams, J.T. ; Smith, R.
Author_Institution :
Dept. of Electr. Eng., Saskatchewan Univ., Saskatoon, Sask., Canada
Abstract :
Two types of microstrip antennas are presented which do not excite the dominant TM/sub 0/ surface wave, and thus have a radiation efficiency of 100%. The first design is a circular path antenna with a ´cored´ substrate, in which a circular piece of substrate material is removed from the region directly below the patch, with the resulting hole filled by a material (such as air) which has a lower permittivity. The second design consists of an annular ring patch which is short-circuited to the ground plane at the inner boundary. Both designs are based on the concept that a circular ring of magnetic current of appropriate radius will not launch any TM/sub 0/ surface wave power. Results are shown for the normalized E-plane field measured from a conventional circular patch, and for a cored-substrate patch.<>
Keywords :
antenna radiation patterns; antenna theory; loop antennas; microstrip antennas; annular ring patch; circular path antenna; cored-substrate patch; ground plane; inner boundary; lower permittivity material; microstrip antennas; normalized E-plane field; radiation efficiency; Circuits; Gold; Magnetic domains; Magnetic materials; Microstrip; Patch antennas; Permittivity; Propagation constant; Resonance; Surface waves;
Conference_Titel :
Antennas and Propagation Society International Symposium, 1991. AP-S. Digest
Conference_Location :
London, Ontario, Canada
Print_ISBN :
0-7803-0144-7
DOI :
10.1109/APS.1991.174775
