Development of impulse GPR antennas

GPR(Ground Penetrating Radar)is widely used for the detection of anomalous objects in the shallow part of the earth. While GPR has a strong point of high resolution, as well known, the depth of investigation is small. Expanding the detection range, therefore, is a matter of the utmost concern in GPR. In GPR, an impulse GPR is most popularly used. The performance of an impulse GPR is greatly related to the characteristics of antenna, the shape of which generally shows like a bow tie. The authors, therefore, have attended to the fact that the current of high frequency like a radar intensively flows along a edge of conductor, and have tried to develop new antennas with a high performance and a light weight. In this paper, the three cases of a V-shaped, a multi V-shaped and a spiral antenna are introduced. In comparison with the test results of three cases, the case of a spiral antenna seems to show the highest performance in the regard to the points of the detection range and a light weight.