Abstract

This paper presents the analysis and design of on-Silicon dielectric resonator antennas (DRAs) for energy harvesting applications. The proposed antennas, operating at 24 GHz and excited through a simple microstrip line, are built on a high-resistivity silicon substrate 0.525 mm-thick. The design of cylindrical and rectangular resonators using sapphire as dielectric material is first described, leading to 80% of maximum radiation efficiency and gain equal to 5.15 dBi. Given the increasing attention to system-on-a-chip (SoC) circuits, the second study proposed in this paper aims to a complete integrated solution, describing all-Silicon DRAs, both in cylindrical and rectangular shapes. Very promising performances are obtained in this case, too, from the twofold point of view of compactness and efficiency (75% radiation efficiency and gain equal to 4.72 dBi), if compared to standard solutions on Silicon. As regards the fully-silicon solution, a first hypothesis of rectifier is presented, obtaining a 33% RF-to-dc conversion efficiency at 8 dBm with about 3V as maximum dc-output voltage. As a last step of the proposed study, an investigation on the miniaturization of DRAs operating at millimeter waves is described, exploiting high permittivity materials. In particular, a dielectric resonator antenna with εr = 50 is studied.