Microstrip Antenna Array of Connected Elements Using X-Shaped Connection Line

Unlike multitudinous research works hammering at decoupling closely spaced antenna array, this letter introduces an X-shaped connection line to strengthen mutual coupling between array elements. Through adding the structure, a five-element linear E-plane microstrip antenna array exhibits comparable performance to a fully fed one, obtaining high broadside gain and low sidelobe level (SLL) and costing less owing to fewer excitations and more simplified feeding network. Also, the structure is valid for a wide range of element spacing. A typical microstrip antenna array at 5.7 GHz is fabricated to verify the feasibility, which exhibits 15.71 dBi broadside gain and -12.18 dB SLL. The results reveal its promising application in a larger array or two-dimensional array.