Double Loop Inductive Feed Patch Antenna Design for Antimetal UHF RFID Tag

Figure 3

Impedance tuning and optimization of the antenna. (a) Input reactance curves of the antenna with different loop length ( mm,  mm,  mm,  mm, and  mm). (b) Input resistance curves of the antenna with different gap width ( mm,  mm,  mm,  mm, and  mm).

(a)

(b)