Switchable patch antenna for RFID shelf reader system

摘要

A switchable patch antenna includes a ground plane, a metal patch, at least two feed lines and a switch. The metal patch is positioned adjacent, but not in contact with, the ground plane. Each feed line is electrically connected to the metal patch. Each feed line is substantially orthogonal to at least one other feed line. The switch is electrically connected to the at least two feed lines. The switch is operable to sequentially select between the at least two feed lines for exciting the switchable patch antenna.