Electronic Beam-Steering IC for Multimode and Multiband RFID

The performance of an RF identification (RFID) system can be limited by the static radiation pattern of a reader or interrogator. In this paper, a novel and low-power CMOS chip has been designed to enable beam steering for the RFID interrogator. This is suitable for the RFID system, operating from 900-MHz to 2.4-GHz bands, which uses passive and active RF tags. Our solution does not change the basic transceiver design in order to minimize the cost of the system. The chip has been implemented in 130-nm CMOS. It can provide up to eight time shifted signals to feed the multiple RF synthesizers in a phased array. This is suitable for the RFID reader, which requires multibands and multimodes, covering ISO-18000-6, Electronic Product Code, and IEEE 802.11b/g standards. The size of this die is 1.2 mm² and it consumes only 10 mA. It can provide multiple delayed signals with 5-ps resolution. This will translate to a 2deg scanned angle at 2.4-GHz band. Measured results for the integrated circuit and phased arrays will be provided.