Novel ultra-wideband “robe” antenna on high-loss paper substrate

This paper presents a wide-band monopole antenna structure printed on a flexible and low cost 104-um thick E4D paper. In order to begin the design process, electromagnetic properties of E4D paper were characterized using the cavity perturbation method with a cylindrical cavity. Then a microstrip fed antenna was designed and optimized to reach a good matching in a wide range of frequency, from 2 GHz to 10 GHz including two WLAN bands. The proposed antenna is thin, flexible, rather compact, has good performance with return loss of over 30 dB and 50 dB at 2.45 GHz and 5.5 GHz, respectively. It exhibits very large bandwidth, from 2 GHz to over 10 GHz. The radiation patterns are nearly omni-directional at both frequencies 2.45 GHz and 5.5 GHz. The design was realized by screen printing technology at CTP France. The measurement results for all six fabricated prototypes are in good agreement with the simulation that confirms the validity of the design.