A Millimeter-Wave Broadband Tri-Mode-Composite Complementary Source Antenna Array

A novel tri-mode-composite complementary source antenna is presented. The electric current source of the antenna is provided by a planar electric dipole mode, while the equivalent magnetic source is supplied by an aperture mode and a dielectric resonator (DR) mode. The combination of the three radiation modes paves an effective approach to improving the bandwidth of the complementary source antenna. The antenna is excited by employing a directly fed probe, which guarantees promising impedance-matching characteristics throughout a bandwidth of about 70%. With the use of the proposed antenna element, a millimeter-wave
$8\times 8$
array is designed and tested. The measured results confirm that the array has a broad bandwidth of 66.7% for both |S
$_{11}\vert \lt -10$
dB and gain variation of less than 3 dB, which is wide enough to simultaneously cover all of the millimeter-wave bands for the fifth-generation (5G) communications. The radiation patterns of the array are also stable and symmetrical over the entire operating band. Benefitting from the simplified substrate-integrated geometry and the satisfying electrical performance, the proposed antenna would be a promising candidate for advanced millimeter-wave systems.