Patent ID: 8077044
Filing Date: 2011-12-13
Classification: H01Q

Abstract:
1. An RFID tag comprising: a dual-port RFID chip having a first port and a second port, wherein the first port has a first RF terminal and a first ground terminal, and the second port has a second RF terminal and a second ground terminal; and a shared antenna having a first feedpoint and a second feedpoint, wherein the first RF terminal couples to the first feedpoint located at a first point on the shared antenna, the second RF terminal couples to the second feedpoint at a second point a distance away from the first feedpoint on the shared antenna, and the first and second ground terminals couple to approximately a center point on the shared antenna, wherein a length of the shared antenna is approximately one wavelength, the first point is approximately one-quarter wavelength from a first end of the shared antenna, and the second point is approximately one-quarter wavelength from a second end of the shared antenna, and wherein the dual-port RFID chip and the shared antenna are configured for spatial antenna diversity and configured to reduce sensitivity to multi-path fading in response to a received wireless RFID signal.