Fine-Tuning Impedance Matching Circuit for a Triple-Band Meandered PIFA in Brain-Implantable Bio-telemetric Systems

Abstract

<p>This article presents a study of the tunable impedance matching to our recently reported compact self-matched triple-band brain-implantable planar-inverted-F antenna (PIFA). It operates at Medical Device Radiocommunication Service (MedRadio) band (401-406 MHz) and Industrial, Scientific, and Medical (ISM) bands (902-928 MHz and 2400-2483.5 MHz). To achieve this, we investigated the optimal reflection coefficient characteristics of PIFA at desired frequencies by employing four pi-and T-type matching circuits. Our results show that a T-type circuit selected for further assessment provides suitable fine-tuning possibilities for all combinations of desired upwards and downwards frequency-tuning of the three operating frequencies to ensure reliable wireless implant communications. </p>