Antenna Miniaturization Using Flexible PBG Materials

Antennas play a paramount role today’s communication centered market place. Recently the demands for miniaturization of electronic devices have increased rapidly in which a miniaturization of integrated antennas has confronted the same development. However, antennas and especially the performance parameters of antennas obey physical laws in which the electrical dimensions of an antenna have a major effect on these parameters such as voltage standing wave ratio (SWR) and radiation efficiency. Recently, a new, multidisciplinary field of study called “Electromagnetic BandGap” (EBG) structures have been developed. An EBG structure forms a lattice whose period determines its resonant frequency i.e. the range of frequencies where the stop band exists for transmission of microwave signals. Antennas physical dimensions can be made noticeably smaller applying EBG materials. These advantages of EBG structures allow us to design smaller antennas with high radiation efficiency on high-dielectric substrates such as ceramics. This paper presents how conventional microstrip antennas can be miniaturized using EBG materials with improved performance parameters. In addition, a novel flexible antenna is presented which can be rolled up during e.g. transportation.