Parasitically loaded broad band microstrip antennas for proposed IEEE 802.15.3a (UWB) communication systems

Abstract

High speed ultra wide band PAN links with data rate greater than 100 Mbps would use the proposed IEEE 802.15.3a (USB) protocol harnessing multiple access CSMA-CD and frequency switched OFDM technologies. Two new printed antennas are developed and tested for application in such broad band microwave communication schemes fulfilling required specifications. For the first antenna, one quadrant of a circular microstrip patch is excited with adjustable probe feed and the other three quadrants are electromagnetically coupled to it. Using 1/16" PTFE substrate with epsivT = 2.4 gives ~3% 2:1 V.S.W.R. band width ( about central frequency ) at 10 GHz for a simple circular microstrip patch antenna, but it improves to ~7.5% (with about -32 dB return loss at centre frequency) for the antenna developed. Further introduction of a W-shaped planar slot in the ground plane improves the 2:1 V.S.W.R. band width to ~13% for the second antenna. In both cases there is no radiation pattern distortion unlike other parasitically loaded patch antennas.