Investigations on ACS-Fed Wearable Antenna With Frequency Reconfiguration Between n78 and WLAN Band
摘要
An asymmetric coplanar strip-fed flexible frequency reconfigurable antenna is discussed in this article. The designed flexible frequency reconfigurable antenna is a uniplanar construction that consists of two radiator strips and a ground plane. The strips and the ground are glued on a flexible polydimethylsiloxane substrate having a dielectric permittivity of 2.7 and thickness of 1 mm. An asymmetric coplanar strip feed is incorporated in the proposed uniplanar design to reduce the antenna size significantly. A parametric analysis is conducted to find the best suitable ground and radiator dimensions. The antenna is compact and its overall dimension is 23 mm x 10 mm x 1 mm. An ideal switch (copper strip) is inserted between the two radiating strips to enable reconfiguration in frequency by changing the radiators’ electrical path. During the OFF state of the switch, the antenna radiates from 4.6 GHz to 5.47 GHz whereas it radiates from 3.6 GHz to 4 GHz and 5.72 GHz to 6.3 GHz when the switch is ON. To validate the feasibility of the antenna for wearable applications, off-body, and on-body (Left-hand model) studies are given. The various performance parameters such as reflection coefficient, gain, radiation, and specific absorption rate show satisfactory/acceptable results. A maximum gain of 3.3 dB is noticed at 5.96 GHz during on-body testing. The observed minimum and maximum specific absorption rate values are 1.21 W/kg and 1.56 W/kg averaged over 1 gram of tissue which falls within the limit of 1.6 W/kg. The proposed antenna finds its applications in 5G n78 NR and WLAN bands.