I want to know what kind of antennas can be used in the deep earth.As far as I know,there are only dipole.magnetic dipole. linear arrays,and some kinds of slot antennas can be used for communication or reconnoitre in the ocean or deep earth. I want to know if there are other kinds of antennas can be used,such as microstrip antennas.
As I am still a college student,I am not skilled in this area.So I want to know what should be considerd in designing this kind of antennas.