| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an underground probe antenna for effectively preventing the ringing of radiant radio waves adaptively to the dielectric constant of underground. SOLUTION: This underground probe antenna is constituted of an antenna element 12 which radiate electromagnetic wave to underground and receives reflected electromagnetic waves from an underground buried object, and a cavity 14, and a spacing between the antenna element 12 and the cavity 14 is physically made variable so that the antenna element 12 and a terminal resistance 13 can be matched with a transmission path 11 whose characteristic impedance is made equal in this underground probe antenna. Therefore, the characteristic impedance of the antenna element 12 can be made equal to that of the transmission path 11 and the terminal resistance 13 adaptively to the dielectric constant of underground. Thus, it is possible to provide a satisfactory underground probe antenna that ringing is small.</p> |
