A Low-RCS Reconfigurable Metasurface Antenna With Independent Beam-Switching Capability

Beam-switching antennas with low radar cross section (RCS) are widely used in high-precision tracking systems. However, achieving both low RCS and beam-switching functionality typically requires additional metasurface layers and complex feeding or comparator networks. In this article, a novel low-RCS metasurface antenna with independent beam control is presented. Without introducing any additional layers, the proposed metasurface simultaneously functions as a beam-switching radiator and a linear polarizer. The radiating patch employs dual symmetrically located excitation feed points. A reconfigurable power divider is incorporated into the metasurface to selectively excite antenna elements. The p-i-n diodes are inserted into power divider. These diodes are digitally controlled through an Arduino-based biasing circuit, which provide a flexible and programmable beam reconfiguration. The reconfigurable power divider excites the antenna ports in both in-phase and out-of-phase states. Under in-phase excitation, the antenna produce a summation beam (SUM) beam with single lobe directed at 0°. In contrast, out-of-phase excitation produces a difference (DIFF) beam with two major lobes directed at ±52° and a radiation null at 0°. Under normal incidence, the antenna demonstrates a 10 dB RCS reduction within the 4.0–6.0 GHz and 12.4–15.0 GHz frequency bands. Also it maintains its beam switching performance within 5.45–5.6 GHz frequency band. To validate the design, a prototype is fabricated and measured. The measured results are in good agreement with simulated results.