Abstract: Apparatus and methods for providing a substantially surface independent tagging system are disclosed. A resonant dielectric cavity is defined between upper and lower conducting layers, and closed at one end by a conducting base portion. Incident radiation couples into the cavity and is resonantly enhanced. An electronic device or tag paced at the edge of the cavity experiences a high electric field strength on account of this enhancement and is driven into operation.

Abstract: An electromagnetic radiation decoupler for decoupling radiation in the wavelength range ?min to ?max. The decoupler has a first conductor layer in contact with a dielectric layer which comprises at least one area of absence and the thickness of the decoupler is less than ?min/4n, where n is the refractive index of the dielectric. The dielectric layer may be sandwiched between two conductor layers, one of which has the structure described above. The invention is also directed to methods of using and various articles comprising such a decoupler.

Abstract: An RF screening apparatus comprising a scanning chamber and an RF inspection device or reader, the chamber having chamber walls which are substantially reflective to radiation at a frequency of operation. The chamber walls or at least a portion of the chamber walls may be visually transparent. This enables visual inspection and identification of the occupant and RF interrogation to be performed, substantially simultaneously if desired. RF interrogation signals produced by the reader reflect off the chamber walls, approaching a target tag from an increased number of different angles, thus increasing the chance of a successful read.

Abstract: A device capable of enhancing an electric field to drive an electromagnetic tag into operation is switchable between states to control operation of the tag. Enhancement is provided by a dielectric cavity structure defined between first and second conducting layers. Different states of the device may have different resonant frequencies and read ranges according to the characteristics of the enhancement. As such a container can be provided which includes a tag which switches states on opening, allowing improved tracking characteristics.

Abstract: Apparatus and methods for providing a substantially surface independent tagging system are disclosed. A resonant dielectric cavity is defined between upper and lower conducting layers, and closed at one end by a conducting base portion. Incident radiation couples into the cavity and is resonantly enhanced. An electronic device or tag paced at the edge of the cavity experiences a high electric field strength on account of this enhancement and is driven into operation.

Abstract: This invention relates to the field of an electromagnetic (EM) field shielding paint compositions, in particular, those capable of providing substantially non metallic finish. The paint composition finds particular use in attenuating EM signals that may be used to carry data between communication devices, especially mobile phone and wi-fi devices. EM field shielding paints are typically available in jet-black or bright metallic finishes and usually possess limited scratch & abrasion resistance. The paint composition provides a one-pot solution to furnish a composition which has the visual appearance of a domestic type paint i.e. one with a non-metallic finish, with the ability to shield electromagnetic radiation. The composition comprises a supported metallic flake and a pigment, which have been provided in a narrowly defined range to furnish a desirable non-metallic appearance and possess electromagnetic shielding properties.

Abstract: An iridescent material comprises a diffraction grating incorporating a plurality of sheets (1) of a first substantially transparent material in parallel alignment and spaced away apart by quantities of a second substantially transparent material (2), the second material having a refractive index significantly lower than the refractive index of the first material, the plates being tilted at an angle ? to an axis X and the grating having a period d(X) in the direction of axis X, the angle ? and period d being such that a second diffraction grating is provided along an axis Z, perpendicular to axis X, the second diffraction grating having a period d(Z) and consisting of ten periods or less and whereby, the diffraction conditions of the grating can be simultaneously fulfilled by electromagentic radiation of a range of wavelength thereby causing iridescence.

Abstract: Apparatus capable of enhancing an incident electric field to drive an electromagnetic tag (124) into operation, comprising a resonant dielectric cavity which extends out of a single plane defined between two conducting surfaces (102, 104, 106). The cavity may extend over two or more layers, and can adopt C or S shaped or spiral profiles.

Abstract: An electromagnetic radiation decoupler for decoupling radiation in the wavelength range ?min to ?max. The decoupler has a first conductor layer in contact with a dielectric layer which comprises at least one area of absence and the thickness of the decoupler is less than ?min/4n, where n is the refractive index of the dielectric. The dielectric layer may be sandwiched between two conductor layers, one of which has the structure described above. The invention is also directed to methods of using and various articles comprising such a decoupler.

Abstract: In order to check the authenticity of a banknote or other such document it is printed with two patches of magnetisable ink, and each patch is magnetised to present a multipole sequence of alternating polarity. If the document is folded to bring the two patches together and then rubbed to and fro in the direction of the pole sequences, they will be subject to alternating forces of attraction and repulsion which can be sensed through the fingertips and gives the impression of a physically rippled texture notwithstanding that the patches actually have a smooth surface. The presence or absence of this effect can therefore be used to distinguish between a genuine document bearing such magnetised patches and a counterfeit which may be visually identical but lacks the correct magnetisation. In a variant only one of the patches is printed on the document itself and the other is on a separate “key” device which is rubbed over it to test for the presence of the correct magnetisation.

Abstract: A surface (30) suitable for promoting the formation of droplets of liquid (35) is provided comprising alternating regions of liquid repelling (32) and liquid attracting (33) material in at least one direction across the surface wherein the diameter of the droplets is controlled by the size of the smallest dimension of the liquid attracting material. The surface (30) may be textured and/or form a pattern. Also disclosed are a method and a system of collecting a liquid (35) carried by or condensed out of a vapour comprising passing a vapour across such a surface (30) and a method of purifying a liquid by passing a vapour containing droplets of a liquid over such a surface.

Abstract: An electromagnetic radiation absorber for absorbing radiation in the wavelength range ?min to ?max. The absorber has a conductor layer in contact with a dielectric layer. The conductor layer carries a plurality of apertures of sub-wavelength dimension and the thickness of the absorber is less than ?min/4n, where n is the refractive index of the dielectric. The dielectric layer may be sandwiched between two conductor layers, one of which has the structure described above. The invention is also directed to various articles comprising such an absorber.

Abstract: A surface (30) suitable for promoting the formation of liquid (35) is provided comprising alternating regions of liquid repelling (32) and liquid attracting (33) material in at least one direction across the surface wherein the diameter of the droplets is controlled by the size of the smallest dimension of the liquid attracting material. The surface (30) may be textured and/or form a pattern. Also disclosed are a method and a system of collecting a liquid (35) carried by or condensed out of a vapour comprising passing a vapour across such a surface (30) and a method of purifying a liquid by passing a vapour containing droplets of a liquid over such a surface.

Abstract: This invention relates to a security label for the detection of counterfeiting and tampering. The invention comprises a combination of an iridescent laminated or multilayered material with a lenticular layer. The iridescent layer exhibits an angular dependence in its coloration in reflection and/or transmission and the lenticular layer acts as a filter to light of a given angle of incidence.

Abstract: A surface (30) suitable for promoting the formation of droplets of liquid (35) is provided comprising alternating regions of liquid repelling (32) and liquid attracting (33) material in at least one direction across the surface wherein the diameter of the droplets is controlled by the size of the smallest dimension of the liquid attracting material. The surface (30) may be textured and/or form a pattern. Also disclosed are a method and a system of collecting a liquid (35) carried by or condensed out of a vapour comprising passing a vapour across such a surface (30) and a method of purifying a liquid by passing a vapour containing droplets of a liquid over such a surface.

Abstract: An iridescent material comprises a diffraction grating incorporating a plurality of sheets (1) of a first substantially transparent material in parallel alignment and spaced away apart by quantities of a second substantially transparent material (2), the second material having a refractive index significantly lower than the refractive index of the first material, the plates being tilted at an angle &thgr; to an axis X and the grating having a period d(X) in the direction of axis X, the angle &thgr; and period d being such that a second diffraction grating is provided along an axis Z, perpendicular to axis X, the second diffraction grating having a period d(Z) and consisting of ten periods or less and whereby, the diffraction conditions of the grating can be simultaneously fulfilled by electromagentic radiation of a range of wavelength thereby causing iridescence.