Horizontally stacked inverted U-shaped dual-band implantable antenna with circularly polarized for biotelemetry application

Abstract

A horizontally stacked inverted U-shaped dual-band implantable antenna is proposed for RFID and health care monitoring implantable applications. The designed antenna operates at 0.952 GHz ultrahigh frequency band (UHF; 0.951–0.956 GHz) and 2.4 GHz industrial, scientific, and medical band (ISM; 2.4–2.4835 GHz) in a suitable feeding scheme. The shorting pin is used on the radiation patch to minimize the antenna structure. The final dimension of the designed antenna size is 9 × 9 ×0.635 mm^3. The defected ground structure (DGS) helped to produce radiation with circular polarization (CP) at 2.4 GHz resonant frequency. The designed antenna achieves an axial ratio (AR) bandwidth of 20% at 2.4GHz resonant frequency. The antenna is designed on Rogers RT Duroid 6010 substrate and fabricated. The same dielectric material was used as a superstrate. At both the UHF and ISM frequency bands, the experiment was conducted using skin-mimicking gel and minced pork. The horizontally stacked inverted U-shaped antenna has a high peak gain of -27.5 dBi at 0.952 GHz. The computed maximum specific absorption ratio is within allowable bounds and complies with IEEE safety criteria.