Geotextile Antenna Design for Mobile Phone Cooperative Communication Relay Node

Abstract

The geotextile is widely applied in civil construction where textile materials can offer a distinct advantage. It can be electrified by weaving conductive strips into the textile structure. This could give the geotextile electromagnetic wave transmission capability and make the geotextile material into a geotextile antenna. The geotextile antenna is an ideal candidate for future wireless network relay systems. In this research, the radiation mechanism of woven conductive structure is studied. Geotextile antenna prototypes are designed according to microstrip antenna theory and the prototypes are tested in an operating antenna range. The test result is compared with a computer aided antenna simulation result, and the radiation mechanism of the geotextile antenna is revealed. A logical discussion is given, and the result shows that the woven

structure could disturb the lowest resonant mode of microstrip antenna, while the second lowest resonant mode of microstrip antenna remains. Moreover, the geotextile antennas possess a resonant mode even lower than the lowest resonant mode of microstrip antennas. This is explained by the textile nature giving the geotextile antenna a structure of a half wavelength dipole antenna array. As a result, the radiation mechanism of the designed geotextile antenna is a combination of a half wavelength dipole antenna array and the second lowest mode of a microstrip antenna. The discovered mechanism is useful for design optimization for the future, it is predicted that a low profile, multiband geotextile antenna can be fabricated according to this new theory.