A Broadband Patch Antenna Array With Planar Differential L-Shaped Feeding Structures

This study involved developing a differential patch antenna array featuring a wide bandwidth and improved radiation patterns. The proposed patch array was fed by a planar, aperture-coupled, L-shaped feeding structure to achieve wideband operation. The differential feeding structure improved the current distribution of resonant modes, substantially improving the symmetry of radiation patterns. The array without differential excitation revealed an apparent deflected peak located at an observation angle of 10 degrees at 13.7 GHz. However, using the proposed differential-fed structure, the location of this peak returned to 0 degrees. The measured results indicated a wide impedance bandwidth of 21.5% and a stable gain varying from 10.3 to 11.52 dBi over the frequency range of 11.6-15 GHz.