Wideband Wide-angle SSPP-fed Leaky-wave Antenna withLow Side-lobe Levels

In this paper, a broadband wide-angle leaky-wave antenna (LWA) with low sidelobe levels (SLL) is proposed. The antenna is composed of two parts: a broadband wide-angle scanning spoof surface plasmon polariton (SSPP)-fed circular patch antenna array and electromagnetic bandgap (EBG) structures tiled on both sides of the antenna array. By controlling the coupling distances between the circular radiation patches and SSPP feeding line, the attenuation constant along the radiation aperture is specially designed in a tapered way to achieve low SLL. EBG structures are adopted to reduce the back-lobe levels. Measured results show that the scanning angle of the proposed antenna reaches 82∘. The measured realized gains are from 8 to 15.7 dBi in the operating frequency range from 8 to 12 GHz, with a maximum SLL less than -15 dB. The wide-band wide-angle SSPP-fed LWA with low SLL can find applications in radar detection and microwave imaging.