Dual-Carrier Modular Phased Arrays for Near-Field Links: Polarization-Aware QPSK and Performance Evaluation

This letter introduces a polarization-aware phase modulation scheme for dual-carrier modular phased arrays (MPAs) in near-field communications. Using electric dipole-based modeling and complete vector-field analysis, a quadrature phase-shift keying (QPSK) method is realized through carrier-specific phase offsets. Beam-focusing patterns are examined under matched and orthogonal polarization modes with interference, revealing temporal constellation spinning. Simulations show that orthogonal polarization improves spectral efficiency and interference resilience, enabling secure and efficient near-field communications in future wireless networks.