This paper proposes a microstrip antenna with reduced in-band and out-of-band radar cross-section (RCS) by subtracting the area of weak scattered current on the ground plane. Fourteen square slots were subtracted from the ground plane, reducing in-band and out-of-band RCS while maintaining radiation performance. Modified and reference antenna surface current distributions were simulated and analyzed in radiating and scattering modes. Two antenna prototypes were fabricated and measured to verify the simulation. The proposed antenna RCS was reduced compared with the reference antenna in the frequency range 1–4.4 GHz, including in-band and out-of-band frequency bands. Maximum in-band and out-of-band RCS reduction was 16.3 dBsm at the working frequency, and 19.3 dBsm at 3.4 GHz, respectively

In this study, a new microstrip patch antenna with wideband radar cross-section (RCS) reduction is presented. The RCS of the proposed antenna was reduced by subtracting the current-direction slots of the patch, with the radiation performance sustained not only for the current-direction subtraction, but also for the no modification in the ground plane. Modified and reference antenna were fabricated and measured. The simulation and measurement results showed that the modified antenna reduced the in-band and out-band RCS simultaneously with no detriment to the radiation performance. In the frequency band from 3.9 to 8.1 GHz, the RCS of the modified antenna was reduced in the whole band compared with the RCS of the reference antenna. The maximum RCS reduction was 7 dB at a frequency of 6.7 GHz.

In this paper, a DG (Discontinuous Galerkin) method which has been widely employed in CFD (Computational Fluid Dynamics) is used to solve the two-dimensional time-domain Maxwell’s equations for complex geometries on unstructured mesh. The element interfaces on solid boundary are treated in both curved way and straight way. Numerical tests are performed for both benchmark problems and complex cases with varying orders on a series of grids, where the high-order convergence in accuracy can be observed. Both the curved and the straight solid boundary implementation can give accurate RCS (Radar Cross-Section) results with sufficiently small mesh size, but the curved solid boundary implementation can significantly improve the accuracy when using relatively large mesh size. More importantly, this CFD-based high-order DG method for the Maxwell’s equations is very suitable for complex geometries.