Digital Reconfiguration of a Single Arm 3-D Bowtie Antenna

This communication proposes the reconfiguration of a coplanar-fed single arm bowtie antenna structure by relying on the integration of a digital tunable capacitor (DTC). The coplanar-fed single arm bowtie antenna is presented in two configurations. The first configuration is a 2-D topology with a modified ground plane arrangement. The second configuration employs vertical folding for the ground plane as well as the radiating arm. In addition, vertical copper inserts are embedded within the bowtie single arm to further enhance the compactness of the structure and transform it into a 3-D topology. Both antennas are initially designed to operate at 868 MHz for Internet of Things (IoT) applications, with a digitally reconfigurable frequency operation for wireless communication. The 2-D antenna structure exhibits a 77% size reduction at the IoT operational frequency of 868 MHz in comparison with a similar rectangular patch antenna operating at the same frequency. On the other hand, the 3-D antenna structure reaches 84% of size reduction at the same frequency. A figure of merit (FOM) is derived to prove the superior performance of the presented antenna structure.