Implantable microstrip antenna design and fabrication for biomedical applications

Without restricting movement and treatment of patients, the importance of biomedical telemetry that provides control in distance by means of radio signals has been greater than ever. Thanks to biomedical telemetry, symptoms such as microwave monitoring, arrhythmia, sphygmic, body temperature, respiratory rate, blood sugar, oxygen content of blood can be achieved, and diagnosis and treatment of cancer can be done. In this context, biosensors and implantable antennas having features for these applications have gained considerable attention. Medical İmplant Communication Service (MICS) band was allocated for biomedical application. In this thesis a dual-band implantable microstrip antenna design is introduced with a miniaturized size of antenna 153.35 mm3 (10.5 11.5 1.27 mm) for biomedical telemetry. The proposed antenna design includes in MICS (402-405 MHz) band and 433-434 MHz, 2.45 GHz two Industrial, Scientific and Medical (ISM) bands. The radiating layer of the antenna is composed of three concentric square split-ring elements and three metallic pad placed between them. Also a shorting-pin is directly connects the outer ring element to the ground plane. The antenna is fabricated on the substrate of the Rogers 3010. The same material is used for the superstrate. Also ground planes have three slots that improve resonance characteristic of the antenna. The full-wave analyses of the implant antennas are carried out using CST Microwave Studio, utilizing the time-domain finite-integration technique. During the simulation, the antenna is placed in a one-layer skin model whose dielectric properties are fully frequency dependent. Also, in vitro antenna measurements are made within the context of this thesis. The obtained results are satisfactory. In addition, three different sizes of antenna to show flexibility in design is presented in this thesis. The proposed optimum antenna design offers at MICS band approximately 41.2% bandwidth and at ISM band approximately %5.6 bandwidth. Antenna gains are −39 dB and −22.9 dB and SAR values are 369 W/kg and 396.4 W/kg, respectively.