Electrically small folded ellipsoidal helix antenna for medical implant applications

The design and fabrication of electrically small folded ellipsoidal helix antennas is presented for medical implant applications. With ellipsoidal aspect ratio as an additional variable, such antennas have improved radiation resistance tunability over spherical helix antennas while still providing high bandwidth (low Q) and radiation efficiency with small values of ka. A novel 3-D antenna fabrication procedure based on selective laser sintering (SLS) is utilized to rapidly tape-out the ellipsoidal helix antennas on medical implant packages.