X-band metamaterial absorber for anti-motion detector

Abstract

A motion detector is a device designed for sense motion, particularly humans for security and surveillance purpose. The counter-product of a detector is an absorber. Applied for various modern military and civil technologies, the study of absorber has been expanded to a very wide area, including in metamaterials. This report will discuss on an X-Band Metamaterial Absorber (MMAb) designed for anti-motion detector operating at 10.525 GHz. The proposed MMAb is aiming to achieve a maximum absorptivity that at least 90% of the electromagnetic radiation absorbed. It is expected to have wider operating angle that can be extended at least 60⁰. The design is aspired to reach a very high degree of insensitivity involving polarization through a series of simulation. By using CST Software, the absorber is designed from an orthodox pattern of annulled circle per unit block, which consists of textile-based substrate in between a metal-based ground plate and a top structure. The structure is then simulated in unit cell to determine the maximum absorptivity through a simple design. Through a series of calculation and observation, the parametric study of the structure is implemented, and from that point, the complication of the pattern is increased so that the maximum absorptivity can be accomplished. Some of the parameters concerned are width of the circle, size of a unit cell and angle of operation. As to consider the flexibility of the absorber, the bend factor of the MMAb is also applied in the simulation. The final design will be decided from the highest absorptivity attained in the series of simulation. The MMAb is expected to be flexible enough to be applied as wearable electromagnetic absorber that is sustainable in terms of absorbing electromagnetic wave from most of the definite directions.