A Compact, Wideband, Two-Port Substrate-Integrated Waveguide Antenna With a Central, Double-Slotted, Metallic Plate Flanked by Two Paired of Corrugations for Radar Applications

This communication proposes a compact, wideband, two-port substrate-integrated waveguide (SIW) antenna with a central, double-slotted metallic plate flanked by two paired corrugations for radar applications. The proposed antenna uses a two-layer structure, with a slotted metallic plate with corrugations on the top layer and an FR-4 substrate SIW on the bottom layer. The antenna has compact dimensions of 63 mm x 54 mm (2.32λ
₀
x 1.99λ
₀
) with a low profile of 7 mm (0.26λ
₀
). To understand the operating principle of the two-port SIW antenna clearly, modal analysis is performed for single-port SIW antenna. The antenna satisfies a -10 dB reflection coefficient from 10.15 to 11.58 GHz. Although the separation between the two central slots is minimized to 4 mm (0.14λ
₀
), the isolation performance remains excellent (less than -30 dB). The gain enhancement, with a narrow beam pattern for radar applications, is realized using constructive superposition of in-phase electromagnetic energy from the two slots. In addition, because the antenna has two ports, it also has a beam scanning function from -12° to +12° in its boresight direction. The experimental and simulated results from the proposed antenna are in good agreement.