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A Rolled Dipole Antenna for UWB Pulse Transmission

Ground penetrating radar (GPR) with medium and high resolution is useful for many GPR applications such as archaeology, utility detection and concrete evaluation. Mediumand highresolution GPR generally transmits transient UWB pulses with central frequency of 500 MHz or higher to obtain a sufficient down-range resolution required for detecting relatively small subsurface structures. In this paper we investigate a method for substantially reducing the length of a dipole antenna for a mediumand high-resolution GPR by rolling the wires. Resistive loading with the well-known Wu-King profile [1] is then applied to eliminate late-time ringing. In GPR minimal late-time ringing is important for avoiding masking of radar returns when the targets are shallow-buried. A similar approach has been used in [2] to increase the bandwidth of a V-dipole antenna by slightly rolling the edges of the antenna. Here, nearly the whole length of the dipole is rolled resulting in a spiral-like antenna.