PTD Symmetric Wideband Absorbers

Absorbers play a pivotal role in protecting sensitive electronic devices from unwanted signals. In this work, we present new types of absorbers based on structures that are invariant under the Parity Time-reversal Duality (PTD) transformation. Such structures produce zero backscattering under the illumination of a plane wave at normal incidence. This reflectionless feature is exploited to design wideband absorbers. Numerical results of the proposed absorbers are also discussed.