Two-dimensional microwave band-gap structures

of different dielectric materials

E D V NAGESH¹, G SANTOSH BABU¹, V SUBRAMANIAN^1,*,

V SIVASUBRAMANIAN² and V R K MURTHY¹

¹Department of Physics, Indian Institute of Technology Madras,

Chennai 600 036, India

²Materials Science Division, Indira Gandhi Centre for Atomic Research,

Kalpakkam 603 102, India

^*Corresponding author. E-mail: manianvs@iitm.ac.in

Abstract. We report the use of low dielectric constant materials to

form two-dimensional microwave band-gap structures for achieving

high gap-to-midgap ratio. The variable parameters chosen are the lattice spacing and

the geometric structure. The selected geometries are square and triangular

and the materials chosen are PTFE ($\varepsilon =2.1$), PVC

($\varepsilon =2.38$) and glass ($\varepsilon =5.5$). Using the plane-wave

expansion method, proper lattice spacing is selected for each structure and

material. The observed experimental results are analyzed with the help of

the theoretical prediction.

Keywords. Band gaps; gap-to-midgap ratio; dielectric constant.

PACS Nos 41.20.Jb; 42.25.Fx