Design and performance of four buried UHF antennas

As a result of a 10-month study by the Institute for Telecommunication Sciences, four UHF antennas were designed and fabricated, and their absolute power gains for elevation angles from
1\deg
to
45\deg
and azimuthal patterns at
5\deg
elevation angle were measured with each antenna buried beneath 1 m of refractory concrete. Relative response of the four antennas, placed in solid granite, to a signal transmitted from an aircraft at ranges up to 300 km were recorded. The performance of the best buried antenna was comparable to that of a
\lambda/4
monopole fed against a
1\lambda
diameter ground plane resting on the ground surface near the buried antenna.