Reconfigurable frequency using electromagnetic band gap structures for single band and wideband

Abstract

Electromagnetic bandgap (EBG) structures have become a favorable field of research within the microwaves, photonics, and antenna design. The unusual properties of this structure such as frequency bandgap [1], in phase reflector arrays [2] and high impedances surface [3] made this structure unique. Several reports have been published to show the ability of EBG structures to improve the performance of the conventional devices when they are integrated together [4]. Some of them are improving radiation pattern of antenna [5], suppressing surface waves for planar antenna design [6], reducing mutual coupling [7] and steering the beam of antenna's radiation pattern for array design [8]. The resonance frequency of EBG structures depend on the equivalent LC network of the structure. To obtain the specific resonance frequency, many researchers proposed different kind of structures which is normally obtained by modifying the shape of EBG patches itself [9]. The operating frequency is tuned by varying the value of total capacitance, C. Several researchers work on tuning the operating frequency of the EBG structures by introducing tuning element, which mean to vary the inductance value. But, that kind of design do not provide much degree of freedom on selecting which frequency band to operate and which types of bandwidth it prefer to be whether single narrowband frequency, multiband frequency or wideband frequency.