LAUSR

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 $\times$ 54 mm ( $2.32\lambda _{0} {\times}\,\, 1.99\lambda _{0}$ ) with a low profile of 7 mm ( $0.26\lambda _{0}$ ). 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 ( $0.14\lambda _{0}$ ), 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.