Other

Emerson & Cuming Microwave Products, Inc.

Michael P Carpenter

David A Gibbs

Mary M Osward

Paul F Dixon

Keith A Soderstrom

A system and method for the use of ultra high frequency RFID tags in conjunction with metal substrates, as well as substrates used to contain liquid. Briefly, an RFID isolator comprised of a material with complex magnetic permeability, used either by itself, or in combination with dielectric isolator material, is interposed between the RFID tag and the substrate. Alternatively, a material possessing at least two distinct dielectric constants is interposed between the RFID tag and the substrate, such that there is a high dielectric constant at the interface with the substrate, and a low dielectric constant at the interface with the RFID tag. This material can be a single material having a dielectric constant gradient, or alternatively, two or more separate layers, each with a uniform but different dielectric constant, sandwiched together.

RFID tags

The present invention provides a system and method for optimizing the performance of 13.56 MHz frequency RFID tags in conjunction with metal substrates. Briefly, a thickness exists for each type of RFID isolator material at which the performance of a 13.56 MHz RFID tag is optimal when used with metal. Varying from this optimal value, in either the positive or negative direction adversely affects read distance. A method of determining this optimal thickness is disclosed, as well as an RFID tag or a substrate being used in conjunction with a material of this thickness.

RFID tags having improved read range

Disclosed is a lens of gradient dielectric constant and methods for the production of same. The lens includes an inner core comprising a cured or fused substantially homogenous blend of glass spheres, curable or fusible binder and, as needed to increase dielectric constant, a low-loss dielectric material. The inner core preferably has a dielectric constant of about 2.0, and an interstitial void volume (representing trapped air space between elements of the cured or fused material) of from about 30% to about 50%. The lens also includes an outer shell layer comprising a cured or fused substantially homogenous blend of hollow glass spheres and curable or fusible resin. The outer shell layer preferably has a dielectric constant of about 1.0, and an interstitial void volume of from about 30% to about 50%. In addition, the lens includes a minimum of one, and preferably two or more intermediate layers, the intermediate layers having a dielectric constant falling between 1 and 2. The intermediate layers are comprised of a cured substantially homogenous blend of glass spheres, resin and, as needed to increase dielectric constant, a low-loss dielectric material. As is the case with the inner core and outer shell layers, the intermediate layer(s) have an interstitial void volume of from about 30% to about 50%. Also disclosed are methods of production for lenses of the type described above.

Lens of gradient dielectric constant and methods of production

A preferred cap for the fill spout of a water bed comprises a screw cap having a top and a threaded flange which is capable of mating with the threaded portion of a fill spout, a turning knob, and a sliding shaft for connecting the screw cap to the turning knob. The shaft allows the knob to reciprocate between a first position substantially abutting the top of the cap and a second position raised above the top. In the raised position, turning of the knob turns the screw cap through the shaft, thereby unthreading or threading the screw cap onto the threaded portion of the fill spout. The knob may also be used as a handle to apply sufficient force to extract a retracted fill spout from its stored position in the envelope of the water bed. To enhance sealing of a cap in a water bed, a sealing thimble may be used to fill the inner volume of the fill spout. An outwardly projecting flange of the thimble bears against the rim of the fill spout. When placed initially into the fill spout, the sealing thimble will reduce spillage while a screw cap is affixed to the fill spout. When firmly in place under the pressure of the screw cap, the sealing thimble will add greater insurance against seepage and leakage of the water bed through the spout.

Cap for the fill spout of a water bed

A flotation mattress and a method for making same. The mattress is comprised of flexible, liquid-impermeable material sealed to form a liquid impermeable envelope. One or more damping chambers are disposed within the mattress which damping chambers have means for liquid communication between the portion of the liquid within the interior of the chambers and liquid around the chambers. The damping chambers impede wave motion generated by an imposed pressure on the mattress by operating as physical impediments to wave propagation and, additionally, by providing countervailing liquid flow from the interior of said chambers into the surrounding liquid body within the envelope.

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Acton, MA, United States of America

Michael P Carpenter