Dispersion Manipulation Method for Ultrahigh-Frequency Band Reconfigurable Absorbers

The limitations between thickness and bandwidth have greatly constrained the application and development of ultrahigh-frequency (UHF) band absorbers. Therefore, a reconfigurable absorber model based on a new concept of dispersion manipulation method (DMM) is set up. DMM exhibits an impedance low-frequency dispersion manipulation and implementation method. Its dispersion characteristics could satisfy the requirement of impedance matching at UHF band with a low profile. With the reconfiguration of the varactor, the DMM absorber could further achieve low-profile tuning absorption with a relatively broad bandwidth. The analysis and implementation of the absorber model are performed by equivalent circuit and surface field distribution. The final design is easy to fabricate and tune. The measurement result shows a −10-dB tuning absorption band from 0.3 to 3.5 GHz, while the thickness is only $0.034\lambda _{\text {L}}$ , in which $\lambda _{\text {L}}$ is the wavelength of the lowest operating frequency.