University of Bristol

Pervasid Limited

Hewlett-packard Company

Ian White

Richard Vincent Penty

Sabesan Sithamparanathan

Martin Neuhaus

Michael Renne Ty Tan

David George Cunningham

Siyuan Yu

Mark Charles Nowell

Geoffrey Charles Allen

Peter John Heard

Philip Dowd

Lutz Raddatz

An RFID system comprises an array of antennas each configured to emit a plurality of beams in different directions. The beams of each pair of adjacent antennas are directed towards one another and overlap. A pair of adjacent antennas transmits simultaneously and the overlapping beams interfere to create an interference pattern. An RFID reader controls the relative phase and/or frequency of the beams to move the interference pattern to read an RFID tag within the moving pattern. As the chance of a RFID tag responding to an emitted beam generally increases with signal strength of the reader beam an area of constructive interference means that RFID tags in that region are more likely to respond to the signal. The system can cover a large proportion of the area below ceiling-mounted antennas, where cover generally means that RFID tags in that area will be successfully read.

Systems and methods for reading RFID tags

An optical crosspoint switch structure is disclosed. The switch permits light signal to be diverted from any arbitrary number of input ports to any or several of an arbitrary number of output ports. The switch consists of two groups or intercepting optical waveguides formed on a planar substrate, which are the input and output waveguides respectvely. At each intersection another waveguide is formed above the input and output waveguides. Optical coupling between this upper waveguide and the input/output waveguides is controlled by an electrical or optical signal. The upper waveguide has a corner mirror at the intersection. When the control signal allows, light couples from the input waveguide to the upper waveguide. After being reflected by the corner mirror, the light couples from the upper waveguide into the output waveguide. The upper waveguide incorporates the active switching element. Allowing high modulation depth and low crosstalk level.

Optical crosspoint switch using vertically coupled waveguide structure

A vertical cavity surface emitting laser device ( ) has a discontinuity ( ) formed within the body of the device. When the device is in use, the direction of polarization of light emitted from the device is substantially aligned with a boundary of the discontinuity.

Laser devices

Multimode communications systems and method using same

Growing community of inventors

Bath, United Kingdom

Ian White