Flexible Asymmetric Radio Frequency Data Shield

摘要

The present invention is a thin and flexible asymmetric radio frequency shield in the form of a multi layered sheet, offering a high level of electromagnetic shielding in terms of radio frequency signal penetration through the thickness of the shield, one side of which is electrically conducting and reflects radio frequency signals while the other side is electrically insulating and absorbs radio frequency signals. Embodiments include a shield placed in the outer currency compartment of a wallet whereby the contents are shielded, while allowing a frequently used RFID card or document, such as a travel or identity card to be used without needing to be removed from the wallet. The shield may also be used in any other circumstance where a thin and flexible asymmetric radio frequency shield of such a nature is of utility.

主权项

1. A flexible asymmetric radio frequency shield, offering a high level of security in terms of radio frequency penetration through the thickness of the shield, at radio frequencies relevant to the particular deployment, embodiment, use or application of said shield, being in the form of a multi layered sheet, made up of a flexible high electrical conductivity radio frequency reflecting component and a flexible low electrical conductivity radio frequency absorbing component, attached together in such a way that one side of said shield reflects radio frequency signals while the other side absorbs radio frequency signals, said radio frequency reflecting component consisting of a layer or layers of electrically conducting materials such as electrically conducting radio frequency attenuating fabric, metallic foil, conductive polymers or other suitable electrically conducting materials, or a combination of these, said absorbing component consisting of dielectric or magnetically susceptible particles, or other radio frequency absorbing particles, or a combination of these, distributed through a flexible low electrical conductivity matrix material, as a single layer or as multiple layers, such that an appropriate reduction of electromagnetic radio frequency energy in terms of signal return from the reflecting component is achieved at appropriate frequencies to fulfil the requirements of a particular deployment or embodiment of said shield, and in addition said shield may be furnished with, where deemed appropriate, a layer or layers of any other material or materials, present for reasons not directly connected with the radio frequency shielding functions of the present invention, either internally or externally, and these may extend over part of, the entirety of, or beyond the radio frequency shielding area of said shield, and all layers making up said shield to be permanently bonded together using flexible non-conductive adhesives, or some other suitable method, and further said shield may be furnished with any fittings or attachments deemed appropriate to a particular deployment or embodiment.