CPW-Fed Miniaturized Implantable Patch Antenna with Circular Polarization for Bio-Medical Applications

This paper presents the design of a miniaturized implantable patch antenna with circular polarization for wireless biomedical applications. The suggested design of coplanar waveguide fed implantable patch (CPW-IP) antenna operates at the Industrial, Scientific, and Medical (ISM) band (2400–2500 MHz). The antenna consumes a compact volume with dimensions of 5× 5 × 2.54 mm³(63.5 mm³). The single band is realized in a rectangular patch with substrate material Rogers 6010 (εr= 10.2, tan δ = 0.0023). The compact CPW-IP antenna was analyzed in three-layer and single-layer tissues simulated using an HFSS environment. The antenna has an axial ratio (AR) < 3, the peak gain of -20.1dB at 2.48GHz, with a return loss of - 25.6dB. The antenna with the three-layer tissue resonant frequency shifted to 2.46GHz and return loss is -24.8dB, with the single-layer tissue frequency shifted to 2.45GHz and return loss -24.1dB respectively. The antenna simulated results show that the 10-dB impedance bandwidth is 30 MHz. Circular polarization (CP) is obtained by taking the circular slot on the rectangular patch. The specific absorption rate (SAR) is below 0.92 W/kg for 1 g of tissue with a maximum input power of 100 mW. Furthermore, the CPW-IP antenna's salient features are analyzed with state-of-the-art implantable patch antennas.