Dual‐band electrically coupled loop antenna for implant applications

Recent low power implant to off‐body communication systems uses both medical implant communication services (MICS) and industrial, scientific, and medical (ISM) frequency bands. In these systems, MICS band and ISM band (2.45 GHz) are dedicated for data transmission and wake‐up signal, respectively. This dual band operation which incredibly extends the life time of battery forces designers to use dual band antennas in both implant and off‐body sides. In this study, a dual band implant electrically coupled loop antenna is proposed. This antenna as dual of planar inverted‐F antenna is a magnetic antenna with inherently low near zone electric field and therefore produces low specific absorption rate (SAR) inside the body. The antenna is miniaturised using a lumped capacitor. In spite of small size of 5 × 5 × 3 mm 3 , the simulated 1 g average SAR is smaller than reported dual band implant antennas in both frequency bands and makes the proposed antenna a good candidate for implant applications.