New Approach of Radiation Pattern Control for Leaky-Wave Antennas Based on the Effective Radiation Sections

In this paper, a new radiation pattern-control approach for leaky-wave antenna designs is proposed based on the theory of effective radiation sections. This approach can be used to generate radiation null regions around desired direction or to reduce the side lobe levels of leaky-wave antennas in a simple and efficient way, i.e., by controlling the radiation from the effective radiation sections. The traveling-wave line-source model is employed for simplifying the analysis at first. Then, the approach is implemented in the sub strate integrated waveguide (SIW) long-straight slot Leaky-wave antennas (LWA) by changing the slot width at the locations corresponding to the effective radiation sections (ERSs). The simulation results show that the radiation null region can be introduced around the desired direction, and the side lobe level can be reduced. Furthermore, the cross-polar level can be controlled to a very low level. Experimental results are also given as verification. In addition, the proposed method still has some limitations, which are discussed in detail and will be improved in the future.