Improved Resistive Loading Profile for Ground-Penetrating Radar Antenna Applications

One of the most critical hardware components for the performance of the GPR system is the antenna and the resistive loaded antenna is one of common antennas used in the GPR system. The author extends Wu-King linear current distribution to the double exponential current distribution and modifies the inaccurate part of the Wu-King loading profile and deduces an improved resistive loading profile with high efficiency. The broadband performance of the improved resistive loading profile has been studied; the concept of lengthening coefficient is created and the optimum parameter design curve of the antenna is provided. Numerical calculation shows that the maximum bandwidth and efficiency of antenna can be achieved with the improved loading profile simultaneously. The impedance bandwidth is as high as 40:1, which is much greater than the 3:1 bandwidth of Wu-King distribution when the voltage standing wave ratio is below 3. It exhibits better efficiency than Wu-King profile. The loading profile can reduce the late-time ringing and be widely applied to other resistive loading antenna for GPR applications