A Compact Wideband Leaky-Wave Antenna With Etched Slot Elements and Tapered Structure

A compact wideband leaky-wave antenna (LWA) with etched slot elements and tapered structure is studied. The proposed antenna is composed of an asymmetric-fed multi-section tapered short leaky-wave antenna with two embedded slots and a ground plane with etched slot elements. Base on the concept of LWA, the asymmetric-fed is utilized to excite the first higher order mode. By etching slot elements on the ground plane, the current distribution of this antenna can be influenced to compact the width of conventional LWA. In order to achieve the impedance matching, this multi-section tapered short leaky-wave antenna is embedded with two rectangular slots. This technique not only improves the impedance matching but also suppresses the back lobe. According to the measured results, the impedance bandwidth achieves about 1.30 GHz for 7-dB return loss, which covers the range from 3.30 to 4.60 GHz, and the scanning angle of the measured main beam is about 36°, which covers the range from 17° to 53°. This short LWA is only about 1.14 λ₀ at 3.4 GHz, and the back lobe can be suppressed by 7.5 dB at 4.3 GHz. Due to the etched slot elements on the ground plane, the frequency of the radiation angle is shifted to lower frequency by 750 MHz, which can compact the width of LWA by more than 20%.