Parasitic coupled microstrip antenna using shared aperture technique

Shared aperture based 2 × 2 matrix shaped patch antenna is described here. The 2 × 2 matrix based patch antenna with optimised dimensions is designed from a rotated hollow square shape based patch. Out of four elements, two diagonally placed elements are acting as resonating elements (for L‐band and S‐band separately); rest two acting as parasitic elements. The proposed prototype has a measured impedance bandwidth of 1.54–1.7 GHz in L‐band ( S ₁₁ <−10 dB) and 3.7–4.2 GHz in S‐band ( S ₂₂ <−10 dB). Isolation is better than 20 dB in both cases, with reduced cross‐polarisation, due to the presence of the parasitic elements. Details of the proposed prototype and design procedure are given; the experimental results are also discussed along with potential advantages and applications. The proposed antenna is designed and fabricated using FR‐4 substrate (90 mm × 90 mm).