DESIGN ANALYSIS OF A SEMI-CIRCULAR FLORAL SHAPED DIRECTIONAL UWB ANTENNA INTEGRATED WITH WIRELESS MULTIBAND APPLICATIONS

This work presents a novel structure of semi-circular floral shape slotted antenna for an ultra-wideband (UWB) including WCDMA, Bluetooth and Wi-Max applications. Initially, a semicircular floral shape radiator is designed by inserting an elliptical slot in patch with partial rectangular ground plane. Further, three rectangle symmetrical stepped slots are inserted in ground below 50 ohm micro-strip (MS) feed line which is integrated with stepped quarter wave transformer to achieve an ultra-wide impedance bandwidth. The proposed antenna structure achieves UWB of 4-18 GHz which cover 127% ([S.sub.11] < -10 dB) fractional bandwidth (FBW). Furthermore, ground plane is modified by loading three asymmetrical capacitive folded strip resonators (CFSR), which provide an additional lower frequency communication bands 2100 MHz (2-2.2 GHz), 2400 MHz (2.34-2.47 GHz), and 2700 MHz (2.69-2.75 GHz) for applications of WCDMA, Bluetooth, and Wi-Max, respectively. An optimized dimension of the proposed antenna is 30 * 30 [mm.sup.2] (1.1[[lambda].sub.0] * 1.1[[lambda].sub.0]), which is designed and fabricated on an FR-4 substrate having thickness 1.6 mm and dielectric constant 4.3. The proposed design is computed by Electromagnetic (EM), ADS simulator, and simulation results are validated with measured results.