Ultra Wideband Water Based Polarization Insensitive Angular Stable Microwave Absorber with Conformity Feature for X, Ku, K and Ka Band Application

An ultra-wideband water metamaterial (MM) absorber is presented in this paper. The absorber provides absorptivity of more than 90 % in the bands of 10.54 to 57.09 GHz, with a wide bandwidth of 47.45 GHz. The designed absorber is insensitive to polarization and is stable for angular variations up to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{4 5}^{\boldsymbol{\circ}}$</tex> for both Transverse (T) Electric (E) and Magnetic (M) modes of polarization. The periodicity is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.344 \lambda_{0}$</tex>, where <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\lambda_{0}$</tex> is the wavelength at the minimum cut-off frequency. The thickness of the absorber is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.105 \lambda_{0}$</tex>. As the absorber is thin in thickness, therefore has conformal features. The proposed absorber has a conformal feature and finds applications in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{X}, \text{Ku}, \mathrm{K}$</tex> and Ka bands.