A Diversity-Based Multi-Antenna Design for Comprehensive RFID Tag Reading

In this work, a multi-antenna design is proposed for remotely reading RFID tags on a push cart that passing through warehouse gates. The propagation environment is challenging because the partly closed cart is made of stainless steel. Line-of-sight paths from reader antennas to RFID tags, which are attached on containers, are likely blocked by shelves on the cart. In order to provide a comprehensive reading coverage, several measures were taken to fully diversify propagation paths, eight antenna panels of different orientations, height, and polarizations are installed on poles at the two sides of the gate. Measurements with a four-port reader indicate that by installing two tags on each container, a 100% read rate can be achieved for detection of containers passing through.