Switchable Reflective Point Design for Ultrabroadband Microwave Absorber

This paper presents an effective method for significantly expanding the bandwidth of a microwave absorber. The method is achieved by inserting a special switchable layer into the absorber already designed. This layer reconstructs and modulates the reflective properties of the original lower grounded dielectric layer, thus eliminating the bandwidth limitations imposed by its total reflection points. In addition, the absorption bandwidth can be further extended to below 1 GHz by switching the varactors loaded on the switchable layer. The final measurement results are in good agreement with the simulation, demonstrating a switchable -10 dB absorption bandwidth covering 0.66- 5.89 GHz.