3Padhi SK, Karmakar N C, Law C L. Dual Polarized Reader Antenna Array for RFID Application [C]//2003 IEEE Antennas and Propagation Society International Symposium. Columbus: IEEE, 2003: 265-268.
4Kim J S, Shin K H, Park S M. Polarization and Space Diversity Antenna Using Inverted-F Antennas for RFID Reader Applications [J]. Antennas and Wireless Propagation Letters, 2006, 5(1): 265-268.
5Edward T C. Foundation for Microstrip Circuit Design [M]. New York: J Wiley & Sons, 1981.
6March S L. Phase Velocity Compensation in Parallel-Coupled Microstrip [C]//1982 IEEE MTT-S Int Microwave Symposium Digest. Dallas: IEEE, 1982: 410-412.
7Klein J L, Chang K. Optimum Dielectric Overlay Thickness for Equal Even-and Odd-mode Phase Velocities in Coupled Microstrip Circuits [J]. Electronics Letters, 1990, 26(5): 274-276.
8Kim Wan-Kyu, Lee Moon-Que. A Passive Circulator with High Isolation using a Directional Coupler for RFID[C]//2006 IEEE MTT-S International Microwave Symposium Digest. California: IEEE, 2006: 1177-1180.
