A compact ultra-wideband (UWB) antenna with an
electronically tunable notched band is proposed for UWB
communication applications. The antenna consists of radiating
patch, a combination of three circular patches, and a partial
ground structure. Moreover, the proposed antenna has a
compact volume of 25 mm × 27mm × 0.787 mm realized on a
FR4 substrate with a relative dielectric constant of 4.5. The
antenna design and the simulation results for radiation pattern
and gain are discussed in detail. To obtain reconfigurable
notch band, the ring-shaped slot structure was connected with
a Varactor diode that have a capacitance varied from 0.63 to
2.67 pF, which achieve a continuous tuning notched band
from 5.8 to 8.4 GHz. The frequency characteristics and
radiation performance of the proposed antenna are
successfully optimized with numerical experimentation
techniques using 3D full-wave electromagnetic simulator CST
2014 and Ansoft HFSS that using three dimensional finite
difference time domain (FDTD) method and finite integral
method (FIM) for verification purposes. The antenna was
realized and its performance was measured and compared with
the simulated results. Good agreements between the simulated
and the measured results are found.