Compact printed log‐periodic dipole antenna for water detection by using ground penetrating radar

Abstract

ABSTRACTCompact printed fractal log‐periodic dipole antenna (FLPDA) is proposed for water detection using ground penetrating radar (GPR). First fractal structure is introduced in an antenna design and evolves the traditional Euclidean log‐periodic dipole array (LPDA). A fabricated proof‐of‐concept prototype of the proposed antenna is printed on a FR4 substrate with a relative permittivity of 4.7 on both substrate thickness 1.6 and 9.5 mm with occupied area of 85 × 110 and 60 × 70 cm2, respectively. The fabricated antenna has approximately 75% size reduction as compared to traditional LPDA. The −10dB impedance bandwidth extends from 45 MHz to more than 500 MHz. Both numerical and experimental results show that the FLPDA antenna has stable directional radiation patterns and apparently miniaturized effect, which are suitable for various ultrawideband applications. Main parameters and characteristics of the proposed antenna are discussed using both electromagnetic simulation and measurement. The effect of sandy soil, water layer, and the distance between sand and proposed antennas are also studied. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1225–1232, 2014