[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Robust Design of Low Side Lobe Level Microstrip Antenna Array by Using Lossy Superstrate

摘要： The side lobe level (SLL) suppression technique using lossy superstrate for robust antenna design is proposed. It is conduct by optimizing the dielectric parameters (i.e., relative permittivity, thickness and loss tangent) based on the spectral Green’s function. To validate our method, a 2*2 microstrip antenna array loaded by 2-layer dielectric superstrate is optimized for low SLL. The optimization results show that using lossless dielectric superstrate the optimized SLL can reach -35.2 dB at 35 GHz without considering the fabrication error. Taking the available precision of air gap thickness ((cid:3399)0.02 mm) into consideration, the SLL is raised to -30.4 dB while using lossy superstrate it can be reduced to -35.6 dB at the cost of gain by 5.6 dB. With involving the effect of the feed network in the simulation, the SLL is deteriorated to -34 dB and is lower than -32.3 dB over the operating band from 34.65 GHz to 35.2 GHz.