A Compact and Wideband Linear Array Antenna With Low Mutual Coupling

A low mutual coupling array antenna operating in the Ku-band is proposed. To reduce mutual coupling, side metallic walls with a small resistive film are incorporated into both sides of the dipole antenna. These walls can also help impedance matching across the whole Ku-band. By investigating the current density distribution on the side wall with frequency, the appropriate positions of the resistive films are determined. Finally, the design is tested by measurement, which is in good agreement with simulation results. The performance is as follows: the operating bandwidth (OBW) is 11.9-20.3 GHz (52.2%) for the impedance bandwidth (IBW) with -10 dB and the low mutual coupling band with less than -20 dB. The radiation efficiency is over 63.9%. The active element gain is 1.88-4.57 dBi. The measured array gain is 15-16.7 dBi as scanning the beam from 0° to 45° at 16 GHz. The OBW is almost constant up to scan angle of 45°. The overall dimensions of the array structure with 17 elements are 1.2 × 9.2 × 0.44λlowat the lowest operating frequency of 12 GHz.