The recently proposed complying-divergence implicit finite-difference time-domain (CDI-FDTD) method was demonstrated with relatively superior numerical performance, especially with the unconditional stability of implicit methods and the complying-divergence property. In addition, the complying-divergence property was also extended to and successful utilized in semi-implicit FDTD methods for significantly more efficient and accurate electromagnetic (EM) computations with models containing fine structures in one or two directions. This work offers an effective implementation of the complex frequency-shifted perfectly matched layer (CFS-PML) based on a one-step leapfrog CD-hybrid implicit-explicit FDTD (CD-HIE-FDTD) method with more robust simulations to address more complicated open-domain EM challenges. The stretching factors are initially introduced into Maxwell’s equations to derive a compact first-order differential matrix form. Subsequently, the matrix is subjected to space-time operator splitting to establish a complying-divergence framework with a two-step iterative solution. For more numerical efficiency, we utilize the leapfrog time-stepping strategy to eliminate intermediate variables and get a one-step iterative solution. Moreover, for the aforementioned computational framework, we offer an analysis for the terms of numerical stability and complying-divergence property. Meanwhile, the various examples given in this work also verify the correctness and efficacy of the proposed method.

This paper proposes a mechanically reconfigurable multi-polarization antenna based on a 3D-printed anisotropic dielectric polarizer, offering wide bandwidth, high gain, and extremely low cost. The working mechanism of the dielectric polarizer is analyzed, demonstrating its ability to efficiently convert linear polarization (LP) to circular polarization (CP) over a wide frequency range. Furthermore, the polarizer exhibits subwavelength characteristics. For a given duty cycle, its phase response depends only on the height and is independent of the aperture size. This property enables miniaturized and customized designs of the polarizer’s aperture size. Subsequently, the polarizer is placed above a Ku band waveguide and standard horn antennas. The results show that by rotating the dielectric polarizer and adjusting the positions of the antennas, right-handed CP (RHCP), left-handed CP (LHCP), and dual LP radiation switching can be achieved in the 12.4–18.0 GHz band, verifying the quad-polarization reconfigurability. Additionally, the polarizer significantly enhances the gain of the waveguide antenna by approximately 9.5 dB. Furthermore, due to the low-cost 3D printing material, the manufacturing cost of the polarizer is exceptionally low, making it suitable for applications such as anechoic chamber measurements and wireless communications. Finally, the measurement results further validate the accuracy of the simulations.