A Compact Multiband Multi-Mode Frequency Reconfigurable Antenna for Portable devices

This work presents a multi-band multi-mode frequency reconfigurable antenna. The antenna comprises of a simple geometrical structure along with compact overall size of $0.22\lambda_{\mathrm{O}} \times 0.11\lambda_{\mathrm{O}} \times 0.012\lambda_{\mathrm{O}}$, where $\lambda_{\mathrm{O}}$ is the free space wavelength at lower resonance. A triangular-shaped wideband monopole antenna was converted into a multiband antenna by utilizing three stubs. Afterwards, three diodes were inserted between the stubs and triangular radiator to achieve multi-mode behaviour. A sample prototype was fabricated and tested while measured results are compared with simulated to validate the finding. The proposed compact size antenna could be a potential candidate for portable devices operating inside Wi-Max, WLAN, 5G-sub-6GHz, S-band, and X-band.