Wideband and Miniaturized Phase-Corrected Empty Substrate-Integrated H-Plane Horn Antenna for 5G Millimeter Waves

This communication introduces a substrate-integrated H-plane horn antenna with phase-corrected structures. The quadratic curves etched on the horn aperture improve the impedance matching and the gain performance. The quasi-uniform phase distribution is achieved by the phase-corrected structure, which consists of the quadratic curves and metallized via-holes embedded symmetrically on the top and bottom layers. To integrate with other planar circuits and test the proposed antenna, the transition from microstrip line to empty substrate-integrated waveguide (ESIW) is used. Compared with the optimum horn, the proposed antenna realizes a 60% reduction of the longitudinal length. A wide impedance bandwidth of 22% for
$\left |{ \mathbf {S11} }\right | < -10 \mathrm {dB}$
, which covers the n257, n258, and n261 5G frequency bands (24.25–29.5 GHz), is verified by a fabricated prototype. Moreover, the stable realized gain varying from 9.3 to 11 dBi is obtained during the operating bandwidth.