Investigation of Leaky-Wave Antenna With Stable Wide Beam-Scanning Characteristic

In this article, a compact magnetic dipole (MD) composite right-/left-handed transmission line (CRLH-TL) leaky-wave antenna (LWA) is proposed, which is periodically loaded with rectangular gaps and short stubs. Then, in light of the dielectric resonator with a high dielectric constant, low loss tangent, and good radiation performance, we further add an alumina ceramic block (ACB) to stack on the gap in each CRLH-TL LWA unit cell for forming the MD, and thus, wide beam-scanning range and compactness are achieved. To validate this design, a traditional uniform CRLH-TL LWA is investigated in detail. The results of S-parameters, electrical field distribution, and radiation properties illuminate the effects of introducing the ACB, such as impendence matching improvement and high radiation efficiency. Furthermore, to verify the flexible control of the balanced condition and the attenuation constant by changing the microstrip gap width and the ACB thickness predicted in the circuit model analysis, a nonuniform CRLH-TL LWA with quasi-constant amplitude is fabricated. Experimental results demonstrate a higher antenna gain and the stability of wide beam-scanning range under the condition of a compact design.