Experimental Investigation of Wave Absorber Made of Ring Resonator-Based AMC Structure

This paper deals with an experimental approach for investigating characteristics of an electromagnetic (EM) wave absorber made of artificial magnetic conductor (AMC) structure. An array of ring resonators in symmetrical shape used as the basis of AMC structure is designed to absorb the incoming EM waves at a certain operating frequency. The proposed design of wave absorber made of ring resonator-based AMC structure is deployed on a Flame Retardant (FR) 4 Epoxy dielectric substrate with the thickness of 1.6 mm. The shape and dimension of ring resonator are optimized to work at the certain operating frequency using a unit cell with proper boundary conditions. To investigate the absorptivity rate of proposed wave absorber, resistive elements are incorporated into the ring resonator. Here, the experimental measurement aims to verify the realized wave absorber with the proposed design and to measure the absorptivity characteristics of realized wave absorber. The measured results for the realized wave absorber which takes the dimension of 220 mm × 220 mm have the absorptivity rate, in terms of reflection coefficient (S 11 ), of –16.65 dB and –25.72 dB for the wave absorber without and with resistors, respectively. These results are comparable to the simulated ones with the S 11 values of –18.01 dB and –23.41 dB for the design without and with resistors, respectively.