This paper introduces a new concept where antenna engineering is explored as an 8-ary polarization shift keying (POLSK) technique. A multi-fed circular patch antenna has been used as POLSK modulator/demodulator with 8 polarization transmit/receive states. A full system has been designed, characterized, and successfully demonstrated. The antenna engineering would replace the complex electronic circuitry and make the system less expensive and less noisy. This technique is free from bandwidth limitation and should be attractive for high data rate communications. © 2017 IEEE.