array system. Thesystem re-transmits a signal to the direction of the incoming signal, with the same ... frequency and opposite phase. For the experimentalverification, a 2×2 retrodirective array system is ... designed and fabricated. Experimental results for a metallic cylinder show as muchas 26-dB reduction in reflection 한국전자파학회 한국전자파학회 논문지 하정제, 장성훈, 이용식