S11 parameter measurement

A frequency dual polarized compact implantable antenna is designed and presented in this paper. The proposed circular antenna occupies a compact volume of 9.46 mm3 . To achieve frequency reconfigurability, the antenna uses switching configuration of PIN diodes and it operates at 1.395–1.432 GHz Wireless Medical Telemetry Service (WMTS) band and 2.4–2.48 GHz Industrial, Scientific, and Medical (ISM) band. Another feature of this antenna is its dual polarization capability, which allows it to operate at 1.4 GHz with Linear Polarization (LP) and 2.4 GHz with Right Hand Circular Polarization (RHCP).When compared to a conventional antenna, the proposed antenna design reduces size by approximately 88.6% for feed1 and 80.66% for feed2. Peak gains for the antenna are -31 dB at 1.4 GHz and -28 dBic at 2.41 GHz. The measured -10 dB bandwidths of the fabricated antenna are 11.48% and 6.81% at 1.4 GHz and 2.4 GHz respectively. The measured ARBW value at 2.4 GHz is 7.21%.