Quasi-Periodic Array Modeling Using Reduced Basis Method

Many electromagnetic devices such as reflectarray antennas, metasurfaces, etc., can be modeled as quasi-periodic arrays. In these devices, similar array elements with a few varying geometrical parameters are positioned in a periodic lattice. Compared to modeling of periodic arrays, efficient modeling of quasi-periodic arrays can be very challenging due to the loss of periodicity in the array. In this work, we applied the reduced basis method to integral equation solvers for quasi-periodic array modeling. In this scheme, a new basis set based on the varying parameters is constructed through an offline process. Because of the similarities among elements, the number of basis functions for each element can be much less than direct modeling from geometrical mesh. Numerical examples show that both the computational and memory efficiency are improved compared to direct modeling using method of moments.