Patent ID: 8497797

Claim:
A two-dimensional array antenna comprising: a plurality of unit antennas arranged in a two-dimensional array of m columns and n rows, which are separated by a first distance from each other, on a board (where m and n are integers greater than 1); a first switch selecting one or more transmitting antennas to radiate a pulse signal onto an internal object in a structure from among the unit antennas; a second switch selecting one or more receiving antenna to collect a signal reflected from the internal object from among the unit antennas; a first motor moving a position of the hoard on which the unit antennas are set in array in a transverse direction that is a lengthwise direction of the board; and a second motor moving the position of the board on which the unit antennas are set in array in a longitudinal direction that is a width direction of the board, wherein the unit antennas arranged in the two-dimensional array are moved in the transverse direction using the first motor or in the longitudinal direction using the second motor by a second distance less than the first distance within an area where the internal object is expected to be present, wherein each of the unit antennas is tilted at an angle of 45 degrees with respect to the transverse or longitudinal direction of the board, wherein each of the columns includes both the transmitting antennas and the receiving antennas, and each of the rows includes both the transmitting antennas and the receiving antennas, and wherein adjacent unit antennas are rectangularly arranged in the transverse and longitudinal directions of the board.