Abstract:
This study focuses on the application of microwave-absorbing materials in the design of time-domain pulsed ground-penetrating radar(GPR) antennae.First,this study analyzed the propagation mechanisms of electromagnetic waves inside and at the medium interface of microwave-absorbing materials.Second,this study applied multi-layer foam composite microwave-absorbing materials to antennae in various loading configurations.Third,based on the CST electromagnetic simulation software,this study compared parameters like waveform fidelity,antenna gain,and voltage standing wave ratio(VSWR) for antennae with different loading configurations.Fourth,this study performed systematic modeling and simulation for the transmitting antenna,receiving antenna,stratified ground,and subsurface targets in combination with a real-world application scenario.By examining the characteristics of the target echo signal under various loading configurations for antennae,this study determined the optimal loading configuration of multi-layer foam composite microwave-absorbing materials for GPR antennae.Using the optimal loading configuration, this study designed and fabricated a flat dipole antenna with a shielding shell.Finally,this study conducted field tests using the LTD-2600 GPR with this flat dipole antenna on the ground surface and at an elevated position,clearly revealing abnormal stratigraphic signals at a depth of 5.6 m.Therefore,this study can effectively guide the design and engineering applications of GPR antennae.