Numerical investigation of disordered patch resonator absorbers

In this paper, the absorption properties of resonant patch absorbers are analyzed using the quality factor approach. The total quality factor contributing from both the dissipative quality factor and radiative quality factor is deduced. The resonant circular patch absorbers are studied under the influence of position randomness with increasing filling factor. It is observed that by introducing position disorder, it is possible to enhance the absorption bandwidth of the otherwise periodic circular patch resonant absorbers. This enhancement in absorption bandwidth is obtained due to the coupling among neighboring resonators, which results in broadening of collective resonances. The designed disordered resonant patch absorbers also exhibit polarization insensitivity for oblique incidences for both polarizations. In addition, square patch absorbers are also investigated under the periodic and disordered setting. It is found that the enhancement in the bandwidth of the disordered absorber structures is independent of the shape of the patch resonators, and depends solely on the coupling among the neighboring resonators.