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出版Deep Exploration Technologies Cooperative Research Centre, 2016
URLhttp://books.google.com.hk/books?id=d63LvQEACAAJ&hl=&source=gbs_api
註釋Conclusion: The constructed antennas satisfy the physical dimension requirements of an application and different testing phases for antenna 1 and antenna 2 revealed that both antennas have major radiation lobes along the axis of an antenna conductor. The borehole testing also revealed that antenna 1 outperforms an antenna 2 in terms of target detection present in front of an antenna. However, the constructed antennas are narrow band antennas having a limitation that they lack the ability to estimate the distance of a target from an antenna. Instead the presence of a target can be detected by change in the magnitude of reflection at a time gap of approximately 5 ns - 15 ns from the time wave leaves an antenna. We also found that dielectric loading, while decreasing the resonant frequency of the modified monopole antenna, causes a drop in directionality of the antenna and hence reduces its radiation gain. In order to improve on this design, other alternatives to help broaden the bandwidth of the monopole must be envisaged. The most appropriate solution may come in the form of resistive loading as is current state of the art for the design of resistively loaded dipoles used in commercially available borehole radar systems. The next phase should be to explore if this resistive loading impacts negatively the directivity characteristics of the antenna.