Dual-Band and Dual-Polarized Corporate-Feed Slot Array Antenna Based on a Corrugated Gap Waveguide

This study presents a novel corrugated gap waveguide (CGW) that is designed to support a dual-band and dual-polarized corporate-feed slot array antenna operating at 16 and 32 GHz. By replacing the perfect electric conductor (PEC) in a groove gap waveguide (GGW) with a corrugated surface (CS), a reduced single-mode band, decreased width, and increased transverse wave vector are achieved. Adjusting the size of the electromagnetic band gap (EBG) structure within the CGW enhances the isolation. The antenna design features a seven-layer configuration: the high-band section consists of an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8\times8$ </tex-math></inline-formula> array of radiation slots at 32 GHz, and the low-band section comprises a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> array of slots at 16 GHz. Both subarrays use perpendicular coupling holes and a compact E-plane T-junction for the corporate feed. The feed network is distributed across the four layers to ensure that the low- and high-band networks remain isolated. The low-band port connects to WR-62, whereas the high-band port connects to WR-28. The performance of the antenna is validated through measurements, showing reflection coefficients below −10 dB within the 15.6–16.15- and 31.1–33-GHz ranges. Far-field measurements indicate peak gains of 19.1 dBi at 15.9 GHz and 27.32 dBi at 32 GHz. The radiation efficiency of the antenna ranges from a minimum of 50% at 15.7 GHz to a maximum of 90.8% at 16.5 GHz for the Ku-band, and from 76.4% at 31 GHz to 93.6% at 32 GHz for the Ka-band. In addition, the cross-polarization levels are approximately 35 and 25 dB in the Ku- and Ka-bands, respectively.