GEORADAR ANTENNA Russian patent published in 1998 - IPC

FIELD: geophysics and geology; investigating subsurface layers of earth by sounding with electromagnetic pulses. SUBSTANCE: since georadar pulse propagates in medium with permittivity ε = 4-80, proposed antenna is made of conducting material in the form of paraboloid with radiator (resistor-loaded dipole) placed in its focus; internal space of paraboloid is filled with material having permittivity ε = 16-8 approaching that of surface being sounded. Antenna is filled with anisotropic material having maximal permittivity in direction parallel to dipole arms. Light-weight anisotropic material may be obtained from parallel-oriented ferroelectric ceramic needles. Under discussion is antenna design in the form of cylindrical paraboloid for operation in frequency range of 30-150 MHz. Directivity pattern of antenna is about 10-50 deg. EFFECT: improved noise immunity, narrow directivity pattern, and improved selectivity to polarization of radiated rays. 5 cl, 2 dwg