Integrated Low-Profile Low Radar Cross Section Circularly Polarized Dipole Antenna Array

In this article, an integrated low-profile low radar cross section (RCS) circularly polarized (CP) antenna array based on multifunctional modes generation method is proposed, which can realize good in-band radiation performance and wide out-of-band RCS reduction characteristics on the same layer without additional subassembly except for resistors. By embedding a resistor in the center of a metallic strip, the half and one and a half-wavelength resonant modes are changed into the absorption modes, while the one wavelength resonant mode is excited as the radiation mode when offset feeding at an appropriate location. Furthermore, the CP radiation performance is achieved with four bent and center-rotating-symmetric metallic strip and the sequentially rotated feeding network. The simulation results show that the designed integrated antenna array generates the same left-hand CP radiation performance as the array without embedding resistors, and the monostatic RCS of the array is significantly reduced in the lower and upper bands, with an average reduction value of 10 dB. Prototypes of the designed antenna array with
$4 \times 4$
elements are fabricated and measured to validate the simulation results.