A Radio Frequency Identification (RFID) localization system is provided. The system includes a set of passive RFID tags, each for reflecting transmitted signals. The system further includes an RFID reader for detecting the reflected signals by the passive RFID tags. The system also includes a processor for localizing an object in an area based on the reflected signals by computing signatures using probabilistic macro-channels between the RFID reader and locations of the passive RFID tags. The transmitted signals form inputs to the probabilistic macro-channels, and the signatures form outputs from the probabilistic macro-channels.

Devices and methods for reading multiple types of RFID tags having different frequencies and/or encoding schemes are disclosed. One or more search signals covering a plurality of RFID bands are transmitted. A presence indication of an RFID tag in one of the plurality of RFID bands is detected. An interrogating signal having a carrier frequency tuned to a frequency at which the presence indication is detected is transmitted. A tag response signal comprising tag information associated with the RFID tag is received. A digital response signal based on the tag response signal is digital signal processed to obtain the tag information.

The inductive/capacitive coupling technology and the radio frequency identification devices (RFID) technology are applied to analyze the relative position of multiple RFID tagged objects located within a finite three-dimensional space. The RFID tags of the objects are read by an antenna at a series of resonance frequencies, with an effective reading range of the antenna changing as the resonance frequency changes. The spatial sequence of the objects is derived based on the information of multiple sets of RFID tags in multiple readings. The technology can be applied to a variety of toys and teaching tools, such as the Tower of Hanoi game.

Devices and methods for reading multiple types of RFID tags having different frequencies and/or encoding schemes are disclosed. One or more search signals covering a plurality of RFID bands are transmitted. A presence indication of an RFID tag in one of the plurality of RFID bands is detected. An interrogating signal having a carrier frequency tuned to a frequency at which the presence indication is detected is transmitted. A tag response signal comprising tag information associated with the RFID tag is received. A digital response signal based on the tag response signal is digital signal processed to obtain the tag information.

An incontinence detection system includes an incontinence detection pad for placement beneath a person to be monitored. The incontinence detection pad has a passive radio frequency identification (RFID) tag. A reader is provided and a plurality of antennae is coupled to the reader. The reader includes a bistatic radio frequency (RF) switch matrix which is operable to establish a first antenna of the plurality of antennae as a transmit antenna that is used to wirelessly energize the passive RFID tag and to establish a second antennae of the plurality of antennae as a receive antenna that is used to read backscattered data that may be emitted from the passive RFID tag. The first and second antennae are situated in respective housings that are spaced apart from each other. An arrangement of first and second electrodes on an electrical sheet of an incontinence pad is also provided.

Disclosed is a system for electromagnetic interrogation of RFID transponders including at least one RFID terminal configured to emit an interrogation signal at a frequency F1, at least one RFID device referred to as repeater configured to receive the interrogation signal with frequency F1 and to repeat same towards at least one RFID transponder at the frequency F2, characterized in that the at least one RFID terminal includes at least one RFID reader configured to emit an interrogation signal with frequency F0 and at least one add-on RFID device configured to perform a frequency transposition from the frequency F0 to the frequency F1, the frequencies F0 and F1 being different.

A UHF RFID system is disclosed in which an RFID transponder or tag can be simultaneously powered and interrogated by multiple RFID transceivers. The architecture of the system is such that each transceiver generates its own carrier wave, with a frequency that might be equal to or different from the other units, and the interrogation data is distributed throughout a network of transceivers and modulated by each transceiver unit onto their own carrier waves. During an interrogation period, one or more of the transceivers will be configured as the master unit, generating and distributing the protocols commands. The other units can be configured as transmitters, receivers or transceivers. After each period the units may be given different roles. The proposed setup yields a system with the capability to power and interrogate RFID tags with multiple readers, without compromising the required modulation depth and protocol handling.

An incontinence detection system monitors an area for moisture events and wirelessly transmits moisture-related information to one or more notification devices. The system has a pad that includes a substrate and one or more sensors supported by the substrate. The sensor(s) emit wireless signals indicative of the moisture-related information. A sensor event communication system forwards the sensor signals to another device, such as a notification device. Portions of the system are included in a patient support apparatus, such as a bed.

An information collection system includes a plurality of radio tags and a reading device. Each of the radio tags stores identification information and includes a sensor, an antenna that receives a carrier wave from the reading device, and a data transmission unit that sends measurement data including the identification information and information obtained by the sensor to the reading device after the carrier wave is received by the antenna. The plurality of radio tags send the identification information and the information obtained by the sensor with different natural periods from the data transmission units. The reading device transmits the carrier wave to each of the radio tags, receives data from each of the radio tags, and obtains the data.

A multi-protocol RFID interrogating system employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGOTM RFID backscatter transponders, SEGOTM RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame, to eliminate downlink on uplink interference.