A near-field switched loop antenna array with a circular defected ground structure for precise positioning systems is presented. By switching the loop array, the positions of the densely placed small-sized radio frequency identification tags can be identified. The characteristics of the proposed array are verified by the comparisons to the simulated results and experimental measurements.

[System Specification]

Frequency band: 840~950MHz

Antenna size: 80×80×1.8 mm

Read range: maximum distance of 30mm