Additively Manufactured Frequency/Radiation Pattern Reconfigurable Antenna Based on Monolithically Printed VO2 Switch

The frequency and radiation pattern reconfigurability in antennas is usually achieved by P-I-N diodes, transistor, micro-electro-mechanical systems (MEMS), etc. based switches which are typically attached to the antennas through soldering or epoxies that leads to reliability issue. In addition, most of these switches are expensive as they are realized with complicated and costly fabrication processes. To increase the reliability and reduce the fabrication cost, additive manufacturing is a viable solution, where the switch can be simply printed at the desired place without the need of soldering, etc. In this work, we present fully printed frequency and radiation pattern reconfigurable antenna designs using a custom vanadium dioxide (VO
₂
) ink based monolithically printed switch. In the frequency reconfigurable design, antenna operates at frequencies of 2.32-2.49 GHz and 1.93-2.03 GHz in the "OFF" and "ON" states of the switch, respectively which matches well with the simulations. In the radiation pattern reconfigurable design, an antenna array comprising two elements show a broadside maximum radiation pattern for the switch in the "ON" state and a broadside null in the "OFF" state at 5.2 GHz. The gain difference between the "ON" and "OFF" state is as high as 8 dB, which is beneficial for direction-finding applications.