title: Incident Angle- and Polarization-Insensitive Metamaterial Absorber using Circular Sectors.
abstract: In this paper, an incident angle- and polarization-insensitive metamaterial absorber is proposed for X-band applications. A unit cell of the proposed absorber has a square patch at the centre and four circular sectors are rotated around the square patch. The vertically and horizontally symmetric structure of the unit cell enables polarization-insensitivity. The circular sector of the unit cell enables an angle-insensitivity. The performances of the proposed absorber are demonstrated with a full-wave simulation and measurements. The angular sensitivity is studied at different inner angles of the circular sector. When the inner angle of the circular sector is 90°, the simulated absorptivity is higher than 90%, and the frequency variation is less than 0.96% for incident angles up to 70°. The measured absorptivity at 10.44 GHz is close to 100% for all the polarization angles under normal incidence. When the incident angles are varied from 0°- 60°, the measured absorptivity is maintained above 90% for both the transverse electric (TE) and the transverse magnetic (TM) modes.
authors.affiliation: School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu 156-756, Republic of Korea.
authors.forename: Dongju
authors.initials: D
authors.lastname: Lee
authors.affiliation: School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu 156-756, Republic of Korea.
authors.forename: Jung Gyu
authors.initials: JG
authors.lastname: Hwang
authors.affiliation: School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu 156-756, Republic of Korea.
authors.forename: Daecheon
authors.initials: D
authors.lastname: Lim
authors.affiliation: School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu 156-756, Republic of Korea.
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Hara
authors.affiliation: School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu 156-756, Republic of Korea.
authors.forename: Sungjoon
authors.initials: S
authors.lastname: Lim