Research On Borehole Radar Antenna

As the development of the society, volcanic explosion and earthquake disasters and Resources and environmental problems is prompting human beings continue to explore the Earth below ground. The development of science and technology offers human ground penetrating radar and other advanced tools to conduct subsurface exploration. Borehole radar evolved from ground penetrating radar and it’s detection range is more broad and deep. As the electromagnetic wave transmitting and receiving devices of borehole radar, the performance of antenna directly determine the performance of borehole radar. According to the research situation of borehole radar antenna at home and abroad and dealing with the difficulty of design,a pair of borehole radar antenna has been designed in this paper.The transmitting antenna is omni-directional antenna, receiving antenna is a directional antenna.The main contents of this paper include:1. History and current status of borehole radar,research situation of borehole radar antenna at home and abroad;2. The basic principle of the borehole radar, electromagnetic wave propagation characteristics, and borehole radar system operating frequency selection, the technical indicators and analysis methods of antenna,especially the index of time-domain performance of the antenna;3. Characteristics of Borehole radar antenna,in particular the characteristics of ultra-wideband, ultra-wideband method of antenna loading were discussed in depth,including the well-known Wu-King continuous loading theory and its limitations, the advantage of convenient fabrication in projects of discrete loading,aim for the tail suppression and waveform high fidelity of radiation time-domain pulse,an omni-directional discrete resistor loaded dipole antenna were designed;4. Antenna miniaturization technology,a directional borehole radar antenna were designed uniting media loading and discrete resistive loading,Co-simulation of omni-directional antennas and directional antennas which construct a transmitting and receiving system confirms the principle of directional radar systems;...