On-chip miniaturized antenna in CMOS technology for biomedical implant

Bioimplant devices need to be small to be considered safe. At the same time, one of the major challenges in its design is the size and lifetime of the battery. Therefore, replacing the battery with a miniaturized and integrated wireless power harvester aid the design of sustainable biomedical implants in smaller volumes. This study presents the design of on-chip miniaturized antenna in CMOS technology at 900 MHz for RF energy harvesting system-on-chip (SoC) application. The design approach utilizes 0.18 mu m CMOS technology from SilTerra. Effect of the thickness of the SiO2 substrate to the return loss and gain of the antenna has been evaluated. It is found that thicker substrate provides a better response, but subject to manufacturability of selected process technology. The developed antenna only occupied an area of 700 x 550 mu m(2). The antenna has been fabricated along with integrated matching circuit and rectifier. The measured performance of the antenna deviates from simulation due to parasitic interaction between the antenna and matching circuit structure. This work shows a complete workflow from design consideration to fabrication and measurement setup of CMOS antenna that will not only be applicable to 0.18 mu m CMOS, but to other CMOS technology as well. (C) 2019 Elsevier GmbH. All rights reserved.