*Article* **A Dual-Band Compact Metamaterial Absorber with Fractal Geometry**

#### **Francesca Venneri, Sandra Costanzo \* and Antonio Borgia**

DIMES - Università della Calabria, 87036 Rende, Italy

**\*** Correspondence: costanzo@dimes.unical.it; Tel.: +39-0984-494652

Received: 9 June 2019; Accepted: 6 August 2019; Published: 8 August 2019

**Abstract:** A fractal absorber based on a metamaterial configuration is proposed for dual-frequency operation within the UHF band. The miniaturization skills of the proposed fractal shape are used to design a dual-band metamaterial absorber cell with reduced size (<λ/2 at the two operating frequencies) and a very thin substrate thickness (λ/100). A metamaterial absorber panel is realized and experimentally validated. Good agreements between full-wave simulations and measurement results are demonstrated.

**Keywords:** dual-band; fractals; microwave absorbers; UHF-RFID
