Design of a miniaturized UWB antenna optimized for implantable neural recording systems

Ultra-wideband (UWB) short-range communication systems are valuable in medical technology, particularly for implanted devices, due to their low-power consumption, low cost, and high data rates. Several emerging medical applications require that a miniature data acquisition device be implanted in the head to extract and wirelessly communicate brain activity to other devices. In such applications the antennas, a key component in a wireless implanted device, require extreme biocompatibility and limited size. This paper presents the design of a miniaturized UWB monopole microstrip antenna that is electrically suitable for implantation in the human head. The antenna is fed by a microstrip line on an FR4 substrate, has a size limited to 12mm×12mm, and is optimized against the effects of biological tissues. Optimization is performed numerically with HFSS. The return loss, radiation pattern and specific absorption rate (SAR) performance of the antenna are simulated and compared for three antenna sizes. Based on these results, a suitable UWB antenna is proposed for operation in an implanted neural recording device.