Performance Enhancement of Cavity-backed UWB Printed Monopole Antenna

The performance enhancement of ultra-wide band (UWB) printed monopole antenna for ground penetrating radar application is proposed based on a simple method using cavity. The antenna configuration named as cavity-backed UWB printed monopole antenna is similar to a waveguide transducer in which the probe used for the excitation is replaced with a UWB printed monopole antenna. The used cavity has the cross-section size of 110mm x 100mm with the depth of 75mm. Meanwhile the antenna which is used for performance enhancement is a UWB printed monopole antenna made of a 1.6mm thick FR4 epoxy dielectric substrate with the size of 72.8mm x 60mm. Some of its parameters such as reflection coefficient, gain, and radiation pattern are used as the performance indicators. After fabrication process, the experimentation is carried out by measuring characteristics of realized antenna configuration. It is found that the use of cavity could change the radiation pattern from omnidirectional to unidirectional and enhance the gain up to 6.6dBi at a certain working frequency.