Antenna-based microwave absorber for imaging in the frequencies of 1.8, 2.45, and 5.8 GHz

We propose a microwave imaging structure with GSM, ISM, Wi-Fi, and WiMAX operating frequencies at 1.80, 2.45, and 5.80 GHz, respectively. The suggested structure is based on a microwave antenna-inspired absorber with cavities in resonator layers. Our study, which is validated using simulation and experimental techniques, deals with the absorption of the incident electromagnetic waves at 1.80, 2.45, and 5.80 GHz for creating the image when radio frequency microwave is employed. The above-mentioned three operating frequencies, by which electromagnetic waves are radiated from three different antennas, are read via digital oscilloscope and finally these voltages are converted to 256 gray-leveled pixel values of each cell. During the experimental testing, simulated and tested values complied with each other. Small differences occurred due to calibration and testing errors. The novelty of this study is having image capability with most commonly used frequency bands by absorbing microwave energy. (C) 2018 society of Photo-Optical Instrumentation Engineers (SPIE).