Bio-Matched Horn: A Novel 1–9 GHz On-Body Antenna for Low-Loss Biomedical Telemetry With Implants

We present the Bio-Matched Horn antenna: a novel 1.773 cm
³
on-body antenna for very low-loss communication with wireless implants across the 1-9 GHz bandwidth. To achieve this unique performance, the Bio-Matched Horn is composed of water-filled holes used to mimic the frequency-dependent permittivity of the underlying tissue over its entire bandwidth. The horn shape further allows the proposed antenna to communicate efficiently through the biological tissue for both subcutaneous and deep-tissue wireless implants. Measurement results at 2.4 GHz are in good agreement with simulations and show a transmission loss of 8.01 dB to a 4 mm-deep implant and 19.21 dB to a 2 cm-deep implant. Compared to the previous designs, this is a remarkable improvement by 14.5 and 10.8 dB for subcutaneous and deep-tissue communication, respectively. In this paper, we discuss the operation principle and design of the Bio-Matched Horn, its performance for subcutaneous and deep-tissue implant telemetry, sensitivity to rotational and positional misalignments, and specific absorption rate performance.