Flexibility Assesment of Fully Inkjet-Printed Reconfigurable Antenna With VO2 Switch

With the surge of Internet of Things (IoT) applications, billions of wireless devices need to be manufactured which could be mounted on non-planar objects or be worn by humans. This is where printing flexible electronics can be a game changer. Recently, frequency-reconfigurable radio-frequency (RF) components are in high demand due to multiple frequency-bands in wireless devices. A very important part of reconfigurable components is RF switch. Traditional switches are based on PIN diode, microelectromechanical-systems (MEMS), transistor, ferrite- and ferro-electric based devices. All these traditional switches have their own sets of advantages and disadvantages, however, one issue is common, almost all RF switches need to be soldered or attached to the reconfigurable components. Thus, it is hard to maintain switch configuration in flexible condition. To overcome these issues, we demonstrate a printing technique to fabricate reconfigurable antenna supported on flexible kapton substrate with switch based on VO2 ink. The fully printed antenna operates at 2.5-3.5 GHz when the switch is in the OFF state. When switch is thermally activated in the ON state, it operates at 1.6-2.6 GHz. The printed antenna shows a maximum gain of ~2 dBi at 3.2GHz with concave bending position. Antenna performance in different bent configurations supports its uses for many RF designs that require reconfigurability and tunability.