Metamaterial-inspired Absorbers for Terahertz Packaging Applications

In this paper, thin metamaterial-inspired structures are investigated for wide-band absorption of stray signals for THz packages. The absorber itself consists of a low-index, low-loss dielectric sandwiched between a patterned, two-dimensionally periodic, thin metallic layer, and a metal backing. Numerical simulations were performed using both the finite element (FEM) and finite-difference time domain (FDTD) numerical methods. Design, fabrication and tests were carried out for absorbers having center frequencies of 0.2 THz and 0.4 THz. Ultra-wide bandwidth and strong absorption were obtained by taking advantage of skin-effect losses in metamaterial structures, and through multi-stacking of these structures. Absorbers having high absorption coefficients and bandwidth (> 1THz) can easily be fabricated using the approach demonstrated in this paper. Two measurement approaches are applied to characterize these structures, details of which are presented in this paper.