Triple band-notched UWB antenna based on SIR-DGS and fork-shaped stubs

A compact CPW-fed triple band-notched antenna for ultra-wide bandwidth (UWB) application is presented. By introducing an stepped impedance resonator-defected ground structure (SIR-DGS) and fork-shaped stubs, three sharp notches are achieved at frequencies of 3.5, 5.68 and 7.48 GHz. The proposed antenna working from 2.8 to 11.3 GHz with a voltage standing wave ratio of <;2 is demonstrated, except for the selected notched bands. The main advantage of the antenna is that the frequency of the notched band can be tuned easily in a wide frequency range. A good agreement between the measurement and the simulation was achieved. The measurements confirm that the technique introduces negligible antenna radiation pattern distortion, except at the triple-notched frequencies.