Low cross-polarization antenna array for CASA’s student test bed radar

A series-fed aperture-coupled antenna array is designed using a substrate with a relative permittivity of 1.2 and a thickness of 1.75 mm for the patch antenna. A substrate with a relative permittivity of 6.15 and a thickness of 0.625 mm is used for the feed lines. The array was designed to achieve a sidelobe level lower than 20 dB and a cross-polarization lower than 30 dB. The array presented is a center-fed array composed of two sub-arrays of 6 elements. This configuration makes the array a 4-port array, having two ports for horizontal polarization (H and H_180), and two for the vertical polarization (V and V_180). The cross-polarization and sidelobe levels achieved are -39.11 dB, and 19.3 dB respectively. The half power beam width (HPBW) is around 9deg and the front-to-back ratio (FBR) is -15.84 dB. Isolations SHV and SHV_180 are -26.61 dB and - 23.08 dB respectively.