An Electronically Beam-Scanning Leaky-Wave Antenna with Reduced Sidelobe Levels

In this article, an electronically beam-scanning tapered leaky-wave antenna (LWA) with low sidelobe levels (SLLs) based on Taylor distribution is presented. The antenna comprises 100 electronically controlled slot elements and two groove gap waveguides (GGWs) connected to a power divider. By precisely assigning the location of each slot to control its radiated power, a Taylor tapered illumination can be achieved to suppress the SLLs. To verify the effect of the Taylor tapered illumination, the calculated radiation patterns indicate that the introduction of Taylor tapered illumination can effectively restrain the normal sidelobes with the harmonic lobes generated by higher-order harmonics still remaining at high levels. Therefore, the beams in the single-mode region can achieve a preferable radiation performance after introducing Taylor tapered illumination, as no high-order harmonics exist. The introduction of two GGWs decreasing the equivalent element periods, resulting in more beams in the single-mode region and decreasing the angular interval in beam squinting. The fabricated prototype is measured with a peak gain of 14.9dBi and a minimum SLL of -18.5dB, showing a good agreement with the simulated results. Moreover, the antenna achieves an electronically beams-canning property from 12.6 GHz to 14.0 GHz with a scanning range larger than 108°.