Objective To alleviate the contradiction between bandwidth extension and manufacturability of dual-band FSS, the bandwidth extension technology based on stub loading is studied.

Method  First, the main factors causing the above contradiction by conventional bandwidth extension methods are analyzed. Second, the influence of stub loading on the electromagnetic characteristics of FSS is studied, such as the reactance characteristics, shape, and quantity of stubs. Finally, the first/second transmission passbands of FSS are extended by stub loading on the grid/slots, respectively, and the mitigation effect of stub loading technology on the above contradiction is analyzed in detail.

Results  Simulation results show that compared with the traditional bandwidth extension method, the stub loading technology can improve the dual-band bandwidth by 48.8% and 23.2% respectively under the same metal line width (0.1 mm), and the test results are in good agreement with the simulation results.

Conclusion  Stub loading can effectively alleviate the contradiction between multi-band bandwidth extension and manufacturability, providing theoretical guidance for engineering practice.