Wideband Endfire Antenna Arrays With Reduced Mutual Coupling

ABSTRACT This letter develops a self‐decoupling method for closely spaced wideband endfire antenna arrays based on the modifications of the directors and the metallic ground. Two side‐by‐side placed elliptical shaped directors and ground plane etched with rectangular slots were employed in the design of self‐decoupled antenna element. A two‐element array was constructed with center‐to‐center element spacing of 0.5 λ L . The operational bandwidth of the developed array covers the range of 4.65–5.15 GHz with the in‐band port isolation level higher than 25 dB. To validate the extensibility of the developed self‐decoupling methodology, a 1 × 4 linear array was constructed with the same center‐to‐center element spacing. The simulated results demonstrated port isolation level higher than 25 dB between all ports. The two‐element and four‐element reference and developed arrays were fabricated and measured, the measured results validated excellent consistency between the simulated and measured results.