A miniaturized slotted ground structure UWB antenna for multiband applications

A concept of using slots both in the radiator and in the ground to miniaturize an ultrawideband (UWB) antenna in order to operate at multiband is demonstrated. Initially, a miniaturized circular UWB antenna is designed which results in about 53.5% reduction in total volume and about 46.6% in the active patch area, in comparison to the conventional UWB antenna. To reconfigure the proposed UWB antenna to operate in multiband applications, slotted ground approach is used. The slots in the ground plane of the proposed design affects the surface current distribution due to which the designed antenna operates at 3.7 (middle WiMAX), 5.7 (upper WiMAX), and 7.5 GHz (X-band) with −10 dB reflection coefficient bandwidth of about 5.3% (3.64–3.84 GHz), 5.5% (5.64–5.96 GHz), and 3.7% (7.44–7.72 GHz), respectively. The proposed configuration is compact in size with a total area of only 0.26λ₀ × 0.21λ₀ = 30 × 24.8 = 283.3 mm² at lower resonating band of 2.6 GHz. The designed multiband structure yields good impedance matching, acceptable gain and stable radiation characteristics both in xz and yz plane, across their operational bandwidths.