Wideband Antenna for Underground Soil Scout Transmission

The underground Soil Scout system introduces a need for a small-size antenna capable of adequate radiation efficiency in soils of different moisture contents at the frequency 0.869 GHz. Such an underground antenna is created for the first time. The high permittivity of soil is utilized to downsize the instrument. A prototype design of an underground single-ended elliptical monopole antenna (USEMA) is presented and the performance measured in different soil moisture contents in a soil container. The suggested antenna has good radiation efficiency in a wide soil moisture range.