Dual-Band Slot Antenna for Miniaturized Biomedical Implants

This paper presents a compact-size antenna designed for biomedical implants. The antenna operates at the dual-band of 910 MHz and 2.45 GHz, which fall within the industrial, scientific, and medical (ISM) band ranges. The proposed antenna achieves a significant size reduction with a minimal form factor measuring only 17.64 mm³(7 mm × 7 mm × 0.36 mm). This size reduction is accomplished by employing a printed antenna with a dual spiral-shape slot and incorporating an inverted U structure, contributing to a more compact design. Additionally, a superstrate layer is introduced to enhance the impedance matching and compactness of the antenna further. The proposed antenna showcases several notable attributes, such as its miniaturization, dual-band operation, and commendable gain values compared to alternative implantable antennas. To evaluate its performance, the antenna is simulated within a multi-layered enclosure comprised of skin, fat, and muscle. The proposed antenna's SARs (specific absorption rates) are calculated within the human tissue model at both operating frequencies. This analysis provides insights into the electromagnetic energy absorption by the surrounding tissues, ensuring the antenna's safety for use in biomedical applications.