Ultra Thin Microwave Absorption Film for Noise Suppression of High Frequency Devices

Tue, 11/12/2013 - 4:56pm
DKN Research

DKN Research has commercialized an ultra thin microwave absorption film called Nikram.  The film, manufactured by Nikkan Industries, is capable of suppressing noise from high frequency devices up to 12 GHz. The 42.5-microns-thick film effectively absorbs microwaves and does not require grounding like most traditional shielding. The suppression rate of the microwaves absorbed is 30 dB at 4 GHz and is stable for frequencies greater than 4 GHz. Thin Nikram film reduces incoming noises, outgoing noises, and reflective noises from high-frequency devices simply by attaching it to the surface of any housing without any grounding requirements. This greatly reduces the material’s footprint and weight of the electronic devices; this is especially important when used with mobile products and medical equipment. DKN Research will provide free samples and detailed technical data by request.

Noise suppression is always a concern for high frequency circuit designers whose products include cellular phones and medical equipment. High frequency wireless devices are introduced to the medical equipment industry on a daily basis, and noise suppression is required from these products to manage weak and nervous signals. Noise suppression was traditionally achieved from a buildup of shielding layers with appropriate grounding outside of the circuits.  This process increases the circuit board’s thickness, weight, and manufacturing cost, and is no longer an appropriate method for the new generation of thin and light mobile devices.
The ideal solution is to cover the electronic devices with electric magnetic wave absorption materials. The problem is the materials have specific frequency dependencies and traditional absorption materials can eliminate only magnetic components from electromagnetic waves, and are ineffective with frequencies higher than 4 GHz.  The traditional microwave absorption materials do not need to be grounded, but they must be relatively thick and heavy; still a problem for smaller wireless devices. 

Nikram could provide a practical solution for this problem. The 42.5 microns thick film absorbs microwaves very effectively; the suppression rates of the microwaves absorbed by Nikram are 20 dB at 2 GHz, 30 dB at 4 GHz, and stable for higher frequencies up to 12 GHz.  Nikram film can reduce both incoming and outgoing reflecting noises significantly from high frequency devices.  Circuit designs are less complicated because the thin microwave absorption film is placed on the surface of the device or printed circuit without grounding. The absorbed microwave is converted to heat within the film; however, the amount of the heat is negligible and will not increase the temperature of the small devices. The film itself is flame retardant with a grade of UL VTM-0 and has enough heat resistance for SMT soldering. Nikram is an environmentally friendly material because it does not include any halogen component.
The Nikram film has another interesting characteristic. The absorption film does not reflect microwaves at the surface, so electronic devices that have metallic housings can be invisible to radar searches. Any metallic device that needs to be stealth can now be lighter and thinner when using Nikram compared to traditional absorption methods.

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