Metamaterial assisted hybrid response from frequency selective surface roll off and leaky wave resonator integrated antenna for underground applications

Abstract

In emerging era of wireless technologies such as cognitive radio, wireless sensor networks etc., designing effective low frequency antennas < 1000 MHz and specifically < 700 remains a significant challenge due to its poor (often negative) gain and severely limited bandwidth (≈ 1%), despite exhibiting fair radiation profile. Therefore, challenges to design antennas suitable for above said applications have been taken up in the present investigation. Unlike, other metamaterial antenna, here, a unique approach is adopted by exploring frequency selective surface (FSS) filtering characteristics by employing simultaneous transmissive and reflective feature to achieve hybrid resonance. Additionally, an integrated leaky wave Fabry Perot type resonator is employed to produce additional distinct resonance. The proposed antenna yields resonances (˂700 MHz) with appreciable bandwidths and positive gains at 462.4 MHz (2.5%), 579 MHz (5.9%) and 663.5 MHz (1.9%) with 1.22, 3.5 and 4 dBi, as is confirmed by both the simulations and measurements.