A Compact Beam-Scanning Leaky-Wave Antenna With Improved Performance

A compact microstrip leaky-wave antenna (MLWA) with reduced sidelobe level and increased linear frequency-scanning capability is proposed in this letter. Symmetric Yagi-like elements are introduced, which reduce the sidelobe level by radiating the remaining power at the physical end of MLWA, and make the radiation plane (
xz
plane) symmetric. Defected ground plane is used to optimize the working of Yagi-like elements. Measured results show that the sidelobe is suppressed about 16 dB at 4.8 GHz. To further reduce the sidelobe level, improve frequency-scanning capability, and increase the gain, the leaky section of the antenna is tapered, and two slots of equal dimensions are introduced. The frequency beam scanning is improved compared with the conventional MLWAs by achieving a total beam scan of 78° (from broadside [12°] to endfire [90°]). The measurements performed on the fabricated prototype exhibit good agreement with simulations.