In this work, we introduce a novel series-feed 4-element antenna array that provides wider bandwidth, improved co and cross-polarization isolation, and higher gain. To achieve these three research objectives of miniaturization, bandwidth enhancement, and co-cross polarization isolation improvements, we implemented three different technologies including meandering the radiator, integrating a neutralization line, and antipodal-Vivaldi defects in the ground plane. By using these techniques in a step-wise manner, we were able to enhance the gain of a single-element meander line array radiator antenna by 5.7 dBi and suppress cross-polarization by 7.2 dB at the main lobe. The proposed 4-element antenna array has an overall size of 3.867λg×3.867λg×0.052λg. The antenna provides a measured bandwidth of 9%, covering the 27.2 GHz to 30 GHz band, with a Half-power Beamwidth (HPBW) of 33∘ and a peak measured gain of 11.426 dBi. The main lobe is located at 35∘. We conducted a precise analysis and detailed discussion of the impact of various design parameters. The presented analysis and design were validated through prototyping and testing.