An Ultrawideband Phased Array Based on Exponential Curve Modified Dipoles

In this paper, a novel ultrawideband phased array is presented based on exponential curve modified dipoles. A tightly-coupled exponential curve modified dipole arm is used to extend the operating bandwidth with a simple coplanar strip structure, which avoids the use of additional complex impedance conversion networks and reduces the processing difficulty and cost. The problematic common-mode resonance is moved out of the required operating bandwidth by the shorting pin. A wide angle impedance matching layer is used to improve beam scanning ability of the array. The proposed antenna array achieves 8.5:1 (2.06-17.6 GHz) bandwidth at broadside, with a scanning range of ±45° from 2.06-17.6 GHz (8.5:1 bandwidth) in the E-plane and ±45° from 2.2-17.6 GHz (8:1 bandwidth) in the H-plane, subject to active VSWR < 3. A $6\times6$ prototype was fabricated and measured with good agreement in measured and simulated results, which verify the ultrawideband performance of proposed array.