A Broadband Miniaturized Ridge Substrate Integrated E-Plane Waveguide Horn Antenna With Partly Removed Metal Layers

This letter presents a wideband miniaturized metal-layers-removed E-plane horn antenna, and the antenna is fed by a two-material ridge substrate integrated E-plane waveguide (SIEW). According to the ridge waveguide theory and dielectric slab loaded theory, the single-mode transmission bandwidth of the SIEW is improved. Besides, the impedance match between the substrate and free space is improved by partly detaching the E-plane metal layers of the horn section rather than adding extra substrate. The proposed antenna has been fabricated and measured, with a fractional bandwidth of 107.7% for VSWR < 2.5 (9.3 – 31 GHz), which covers the 5G frequency bands of n256, n257, n258, and n261. Furthermore, as far as the authors know, the bandwidth of this horn antenna is broader than that of most SIW and SIEW horn antennas reported so far.