Implementation of an ultra-wideband planar monopole antenna for operation from 650MHz to 20GHz

The scaling factor in a ultra-wideband antenna is investigated. Here is showed that the lower frequency limit of the bandwidth is reduced as the scaling factor is bigger than unity. Using the obtained results a UWB planar monopole antenna was designed. The measured antenna bandwidth goes from 650 MHz to 20 GHz for a VSWR ≤ 2. The radiation pattern remains almost omnidirectional. The radiator used in this work is a rectangular monopole with a bevel and a height-width ratio technique that optimized the impedance bandwidth.