| The normal mode helical antenna (NMHA) is a common antenna used on transceivers for wireless communications due to its omnidirectional radiation pattern, large bandwidth and small physical size. In this thesis this antenna is used as the base to develop an antenna that will be part of a Crosswell Radar Tomography system. This antenna will be designed to operate in a frequency range from 0.2 GHz to 10 GHz, with an omnidirectional radiation pattern and lest than 10 mm in diameter.; To increase the bandwidth, a new methodology was introduced which combines a NMHA and the properties of a log-periodic antenna, in addition to the following techniques: design of experiments, tape conductor, material support and no uniform diameter.; The final results obtained with an antenna prototype were satisfactory and have been verified with diverse real measurements of the radiation pattern. Two antenna prototypes were sent to the Northeastern University to be evaluated and integrated on the prototype system. |
