A broadband omnidirectional absorber based on a hetero-structure composed of epsilon-negative material and mu-negative material

¹ Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P.R. China
² Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science and Technology, Nanjing 210044, P.R. China

^a e-mail: xkkong1980@gmail.com

Received: 8 January 2014
Revised: 13 March 2014
Accepted: 5 May 2014
Published online: 10 June 2014

Abstract

A broadband omnidirectional absorber which is realized by heterostructures containing a collision plasma layer and a zero − n̅ mirror is theoretically investigated. A collision plasma layer and an appropriate dielectric layer are put on the top of the PC. It is shown to absorb roughly 70% of all available electromagnetic wave in a relative omnidirectional absorption band width 244 MHz. The absorption band edge of the PC is influenced by the range of the reflection band gap. Meanwhile, the absorption range for the transverse magnetic (TM) wave decreases at large incident angle. Compared with some previous designs, our proposed structure has a relative flatter total absorption spectrum over a broad microwave frequency range and using a zero − n̅ gap as a mirror is insensitive to the incident angle. This kind of heterostructure offers additional opportunities to design novel optoelectronic devices.