4-ELEMENT PLANAR ARRAY ANTENNA FOR UWB APPLICATION

A novel low-cost 4-element planar array antenna directly fed by a coaxial cable for U1- tra-WideBand （UWB） application is presented. The proposed antenna consists of 2 ×2 bowtie elements and a simple 1：4 power divider feeding network. Compared to the basic bowtie element, the impedance bandwidth of the array antenna has a significant improvement that the low cut-off frequency is ex- tended from 6 GHz of the bowtie element to 2 GHz. The measured results show that the proposed antenna has a large bandwidth of 2 GHz to 11 GHz for Voltage Standing Wave Ratio （VSWR）〈2, and exhibits a bidirectional radiation pattern and a modest of about 9 dBi at 11 GHz. gain across the operating band and a peak gain