A compact tunable notched-band ultra-wide-band antenna using a varactor diode

Based on a proposed compact ultra-wideband (UWB) antenna, a varactor diode with capacitance range from 1.5pF to 5.5pF is used to realize the tunable notched-band feature of the antenna in this paper. After installing the varactor diode, not only are many primary attractive features remained, but also the antenna shows a good performance in and out of band. At last, Antenna prototype are fabricated and measured on a low-cost two-side printed circuit board and the measured results show that the antenna prototype can provide an operating bandwidth from 3.6-11GHz, except for the rejected bands.