A Frequency Selective Rasorber With Absorption Bands on Both Sides of Passband Based on Screen-Printed Resistive Film

In this letter, a screen-printed resistive film-based frequency selective rasorber (FSR) with absorption bands on both sides of the passband is proposed. Two components make up the FSR: a lossy layer at the top and a lossless layer at the bottom. The lossy layer consists of resistive film-based rectangular patterns which are integrated with metal structures, generating bands of absorption in the two sides of an intermediate passband. The resistive film on the lossy layer is realized by screen-printed conductive ink, which not only can provide more flexibility in design, but also have good planar integration features in practice. The lossless layer provides impedance matching using a square ring slot FSS. Simulated and measured FSR findings show that the absorption bandwidths with absorptivity ≥ 80% under normal incidence are 3.6 GHz to 8.8 GHz and 10.9 GHz to 14.1 GHz, 3.5 GHz to 9.3 GHz and 11 GHz to 15.8 GHz, respectively. In the simulation and experiment, the minimal insertion loss (IL) is 0.24 dB at 10 GHz and 0.47 dB at 10.2 GHz. Within the incident angle of 40°, the FSR can maintain stable performances under both TE and TM polarizations. The proposed FSR in this letter has a practical application prospect in anti-interference systems and stealth radar platforms.