Compact spiral antenna for dual-band on-body applications

A compact dual-band spiral antenna is proposed for on-body applications in this paper, operating at 402 MHz Medical Device Radiocommunications Service (MedRadio) band and 2.45 GHz Industrial, Scientific, and Medical (ISM) band. Initially, a spiral-shaped dipole is adopted to form a miniaturized wearable antenna resonant at 402 MHz to communicate with implanted devices. In addition, four rectangular patches are attached in bottom layer to improve the impedance matching at MedRadio band. Finally, a pair of rectangular strips is introduced to form an additional required resonance at ISM band.