“Hello-Shaped” wideband monopole antennas on paper substrate

In this paper, two monopole antenna structures called by the authors as “Hello 1” and “Hello 2” have been designed based on screen printing technology on the flexible paper substrate of 210-um thickness to cover very wide frequency range focusing on two WLAN bands. The designed antennas have the dimensions of 42 × 28 mm
²
with the return loss of over 20 dB for “Hello 1”, and over 25 dB for “Hello 2” at both frequencies 2.45 GHz and 5.5 GHz. Both antennas have nearly omni-directional radiation patterns at 2.45 GHz while more directive at 5.5 GHz. The total efficiency of the antennas is of 67.3% and 68.9% at 2.45GHz, 65% and 67% at 5.5GHz for “Hello 1” and “Hello 2”, respectively. Two prototypes of each design have been realized and measured to compare with the simulation. As a result, acceptable agreement has been obtained.