Radiation $Q$ Bounds for Small Electric Dipoles Over a Conducting Ground Plane

The radiation quality factors of vertically and horizontally polarized single-mode dipole antennas over a ground plane are investigated and compared with their free-space counterparts. The theoretical Q results are validated using simulation and measurement results of small spherical helix dipole antennas. For vertically polarized antennas, the bandwidth can be enhanced approximately by a factor of two.