PROJECT TITLE :

Considerations for the Design and Placement of Implantable Annular Slot Antennas for Intracranial Pressure Monitoring Devices

ABSTRACT:

Deviation in the performance of measured implanted antennas [like S11 measured by a vector network analyzer (VNA)], compared to that of antennas encapsulated inside an implant and totally embedded in tissue, is not totally understood. This letter presents simulation and measurement results of an annular slot antenna (ASA) for its use in implantable intracranial pressure (ICP) devices operating at a pair of.forty five GHz. ASA is chosen for its higher radiation potency compared to strip antennas such as printed inverted-F antennas (PIFAs) used previously by the authors and another groups. The performance of the antenna ( S11, gain, and radiation efficiency) with a coaxial feed passing through the device and the encompassing tissue is compared to its performance when the feed is applied from inside the device. It is demonstrated that the insulation coating of the outside of the cable in the case of the VNA take a look at, and correct grounding of the outer conductor of the cable within the case of the inner feed, are necessary to reduce the performance deviation. Moreover, measured gain and S21 demonstrate the prevalence of the ASA over the PIFA, thereby implying higher radiation efficiency of the ASA, that is according to simulation results.