A Tightly Coupled Dipole Array with Diverse Element Reflection Phases for RCS Reduction

This paper proposes a novel low scattering tightly coupled dipole array (TCDA), aiming to reduce the radar cross section (RCS) of phased antenna arrays under a certain oblique incident wave. First, we build three types of antenna elements that exhibit similar radiation characteristics but diverse reflection phase differences based on the proposed theoretical analysis. The required reflection phase difference is achieved by using different dielectric superstrates for each antenna element. Then, by arranging the three types of subarrays next to each other, a low scattering TCDA (8 × 9) is designed. Meanwhile, a reference antenna array with a single type of antenna element is also constructed. To demonstrate the effectiveness of the proposed RCS reduction technique, simulated and measured results of the reference and proposed antenna array are compared. Both antenna arrays operate over the 6–18 GHz frequency band and can scan up to ±45° in the E-/H-planes. However, the proposed antenna array achieves a significant monostatic RCS reduction over 8–12 GHz, with a maximum reduction value of 7.55 dB. It indicates that this diverse element reflection phase technique is a good candidate for wideband RCS reduction.