System and method for filtering electromagnetic transmissions

Abstract

A combination of filters for filtering selected wavelengths of electromagnetic radiation is provided on a transparent substrate such as a plastic film or glazing of a window. The combination of filters prevents or attenuates the passage of wavelengths through the substrate into a building, where the passage of the wavelengths into the building could adversely affect people or machinery within the building. The combination of filters is useful improve wireless networks performance by blocking or attenuating undesired electromagnetic interference, and radio frequency interference.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present invention is a continuation of pending U.S. application Ser. No. 11 / 033,298, filed 12 Jan. 2005, which is a continuation-in-part of U.S. application Ser. No. 10 / 445,942, filed 28 May 2003 (now U.S. Pat. No. 7,177,075), which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application Nos. 60 / 395,332 filed 12 Jul. 2002 and 60 / 383,114, filed 28 May 2002, all of which are incorporated herein by reference in their entirety.STATEMENT REGARDING SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable. REFERENCE TO SEQUENCE LISTING [0003] Not Applicable. BACKGROUND OF THE INVENTION [0004] 1. Field of the Invention [0005] The invention relates to a system and method for filtering electromagnetic and visual transmissions, and for minimizing acoustic transmissions for security purposes. More specifically, the invention provides a system and method to prevent unauthorized data collection and information exchange from or withi...

AI Technical Summary

Benefits of technology

[0015] Accordingly, the present invention provides a system and method for filtering electromagnetic, visual, and minimizing acoustic transmissions by using a combination of filters which substantially obviates one or more of the problems due to the limitations and disadvantages of the related art. The invention further provides a system and methods whereby a combination of films has a shielding effectiveness which attenuates the transmission of radio frequency wavelengths there-through and provides effective filtering of UV and IR light with good visible light transmission (VLT) without undesirable color characteristics.

Problems solved by technology

Obviously, the ability of an eavesdropper to intercept such radiation constitutes a significant security risk, which is desirably eliminated from facilities where secrecy is essential.

Although walls, such as brick, masonry block or stone walls may effectively prevent the escape of light frequencies from a facility, radio frequencies pass through walls that are not properly grounded to prevent such passage.

As a result, sensitive or secret data may be gathered from within the structure.

Both alternatives can be extremely expensive.

The disadvantages of a windowless or enclosed structure, however, are self-evident.

In addition to the security risks associated with the passage of certain wavelengths of electromagnetic radiation, acoustic transmission through a window, door or other opening also poses a security risk.

The conventional solar control films described above are, for the most part, incapable of rejecting the wide range of frequencies used for such unauthorized data and information exchange.

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