LAUSR

Switchable rasorber operating between rasorbing and absorbing states can effectively improve its stealth performance within the passband. However, the existing switchable rasorbers utilize single‐order frequency selective surfaces (FSSs), limiting their transmission bandwidth. This work proposes a switchable rasorber with expanded passband utilizing high‐order FSS. First, the switching principle of high‐order FSS is presented, which is then used to design the rasorber with an extended transmission band. The simulated results and experimental verification of the proposed switchable rasorber are also presented. Compared with the existing switchable rasorbers, the proposed device demonstrates the widest fractional transmission bandwidth of 17% and a minimum insertion loss of 0.54 dB in rasorbing state. In the absorbing state, the passband is eliminated and the device exhibits a single absorption band with fractional bandwidth of 89.3%.