Wide Impedance and Pattern Bandwidth Realization Using Fractal Slotted Array Antenna

A wide band iris excited fractal slotted array has been realized and experimentally verified at X band. The design starts with a centered plus shaped slot in the broadwall of a rectangular waveguide and the same has been used in second iteration for fractal configuration, which exhibits dual resonance. The fractal unit cell is optimized for bandwidth by carrying out parametric study of slot-iris combinations and 2.4 GHz bandwidth is achieved for both radiation pattern and impedance response. An empirical expression for conductance of the unit cell has been developed to facilitate design of antenna array using the unit cell as an element. The optimized unit cell has been used for designing a four element array, which exhibits a pattern bandwidth of 1.4 GHz and impedance bandwidth of 2 GHz. The array is simulated in commercial fullwave 3D FEM simulator. The designed array has been fabricated and measured response has been compared with simulated data.