Printed monopole antenna with tunable band-notched characteristic for use in mobile and ultra-wide band applications
A tunable band-notch printed monopole antenna is presented, exhibiting a wide impedance bandwidth from 1.5 to 5.5 GHz with good impedance matching (VSWR???2) and a tunable rejected frequency band from 2.38 to 3.87 GHz. The band-notching is achieved by adding an inner chorded crescent element within a driven element of a similar shape. By varying the value of the varactor, which is placed between the inner and outer arcs, the desired variable rejected can be obtained. Simulated and measured results show wide impedance bandwidth with a tunable band notch, stable radiation patterns, and consistent nearly constant gain. The antenna is suitable for mobile and portable applications.  2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:403412, 2015.
monopole antenna wideband antenna tunable notch varactor diode