Conventional electromagnetic (EM) absorbing materials exhibit fixed EM properties

limiting their ability to adapt to spatiotemporal variations in the ambient EM environment. With the advancement of high-resolution radar imaging systems such as synthetic aperture radar (SAR)

the EM reflection differences between targets and their surroundings can be precisely identified

significantly increasing the risk of target exposure. To achieve effective camouflage under imaging conditions

it is imperative to develop dynamically tunable EM absorbing materials operating in the microwave band that can modulate their EM responses to match the environment

thereby reducing detectability. Recent progress in novel material and device systems

as well as deformation-driven modulation mechanisms

has enabled the realization of broadband EM absorption with large modulation depth. This review summarizes research advances in representative material systems including graphene

diodes

and fluidic media

alongside mechanical deformation-based modulation approaches. The EM modulation mechanisms of various technologies are analyzed

and design strategies for extending modulation bandwidth and enhancing modulation depth are discussed. Finally

future development directions of dynamically tunable EM absorbing materials are proposed.