Design and performance analysis of a <scp>CPW</scp>‐fed circularly polarized implantable antenna for 2.45 <scp>GHz ISM</scp> band
Vipan Kumar, Deepali Thakur
Abstract
Abstract A CPW‐fed, circularly polarized (CP)antenna operating at 2.45 GHz ISM band is investigated for in‐body biotelemetry. Antenna has compact volume of 98mm 3 (14 mm × 14 mm × 0.5 mm) and printed on RO 3010 substrate. By using inverted z‐shaped radiator with square ring‐shaped ground, wide impedance bandwidth of 450 MHz (2.25‐2.7 GHz).In addition, it also contributes to excite two orthogonal modes (TM01 and TM10) for CP generation and 3‐dB axial ratio bandwidth of 170 MHz (2.39‐2.56 GHz)is achieved. Results are simulated in muscle tissue, three‐layer rectangular and cylindrical phantom tissues and measured in pork tissue. Proposed structure demonstrates robust performance in heterogeneous bio‐environment. High gain of −15.96 dB confirms good radiation characteristics, low SAR value of 0.494 W/Kg and radiation efficiency of 2.83% make antenna suitable for low power in‐body bio‐telemetry.