Harvesting Electromagnetic Energy in the V-Band Using a Rectenna Formed by a Bow Tie Integrated with a 6-nm-Thick Au/HfO₂/Pt Metal-Insulator-Metal Diode

In this paper, the first demonstration of a bow-tie antenna integrated with a metal-insulator-metal (MIM) diode for electromagnetic energy harvesting in the V-band (i.e., 40-75 GHz) is presented. We have designed, simulated, fabricated, and fully characterized a 60-GHz rectifying antenna (rectenna) based on a vertical Au-HfO₂-Pt MIM diode with reduced differential resistance. The dielectric used for the MIM structure is a 6-nm-thick amorphous HfO₂ grown by atomic layer deposition. For the fabricated MIM device, we report here a current density of 3 × 10⁴ A/cm² that exceeds the previous values presented in the literature. The vertical MIM-based rectenna is able to efficiently harvest up to 250 μV from an impinging modulated millimeter-wave signal with-20 dBm of available power, thus offering a voltage responsivity of over 5 V/W. The reported results indicate that the proposed approach is well suited for future low-power solutions much sought after for the energetically autonomous 5G terminal equipment.