Design of an absorptive structure for WCDMA band

In this paper, an absorptive structure based on a periodic structure is presented and its absorption performance is examined. This is a single-layer planar resonant structure, and a lossy periodic surface is used for enhancing the absorption characteristic instead of the conventional resistive layer. Using well known structure, we propose a design technique to determine the important design parameter by using a simple equivalent circuit and analytical method. In addition, the method for accurately measuring the reflectivity of the structure is presented, and through measured result the design is verified. The measured result for the proposed absorptive structure, showing a broadband reflectivity response with a fractional bandwidth of approximately 91% below -10 dB, is presented along with other computational results to confirm the function of the structure.