2-D Endfire E-Plane Horn Antenna Array With Novel SISL-Based Waveguide Feeding Network for Millimeter-Wave Applications

This letter presents a 2-D endfire E-plane horn antenna array with a novel feeding structure named by substrate-integrated suspended line (SISL) vertically integrated waveguide (SISL-VW). Compared to the conventional all-metal waveguide counterpart, the proposed horn antenna array is a composite structure of printed circuit board (PCB) and metal waveguide, thus, it possesses merits of low cost, light weight, and easy integration with planar circuits. Different from the conventional planar transmission line such as microstrip line, coplanar waveguide, and substrate integrated waveguide, vertical rectangular waveguide can be integrated with planar SISL along both +Z/-Z direction to form the self-packaged SISL-VW. SISL-VW presents a new integration manner between the metal waveguide and PCB. By utilizing the double-side SISL patch, equal phase and amplitude output of the SISL-VW can be realized to feed the metal horn antenna array. Measured results show that the proposed horn antenna array obtains an -10 dB impedance bandwidth of 23.32-27.1 GHz. At 24.5 GHz, the measured radiation efficiency is better than 90%.