A common misconception is that a Faraday cage provides full blockage or attenuation; this is not true. The reception or transmission of radio waves, a form of electromagnetic radiation, to or from an antenna within a Faraday cage is heavily attenuated or blocked by the cage. However, a Faraday cage has varied attenuation depending on wave form, frequency or distance from receiver/transmitter, and receiver/transmitter power. Near-field high-powered frequency transmissions like HF RFID are more likely to penetrate it. Solid steel cages generally provide better attenuation than mesh cages. [From Wikipedia]

Attenuation is the key information that informs the user of the shielding’s effectiveness. The higher the attenuation, the more effective the shielding. This is not a test that can be done by the seller, and it’s not what takes place when the materials are compromised during the assembly of the shielding materials.

How can you ensure the effectiveness of your RF blocking item?

Attenuation effectiveness requires testing by an independent certified testing company

If someone can’t supply a report from a certified independent company, they cannot make factual claims about the effectiveness of their product. The equipment to test for RF is large, expensive, and is meant for use by professionals. I doubt a Shield Pouch seller has that testing equipment in their office or cut and sew plant!

Know the testing scope

Our SHIELDSAK was tested from 3 MH to 10,000 GHz.   This information is paramount to the actual shielding effectiveness. A Certified Testing Report by an independent source will insure you are receiving trustworthy claims. When people want to keep items with ID chips safe, they can consider an item that is cheap and hope it does the job.

Remember that mobile devices are very different

For a Faraday cage to work properly there must be very high attenuation protection, meaning there can be:

  • No seams
  • No opening anywhere on the SHIELDING pouch
  • No opening where Velcro joins a side seam
  • No zippers
  • Not even so much as a pin hole so small it’s invisible to the naked eye

Then, and only then, can it be called a FARADY cage. LOKSAK has handled the ability to integrate fabric and seams.

Pay attention to the stiffness and size of what is being offered

At SHOT, the soldiers said they were given SHIELDING devices, but don’t use them due to the bulk, stiffness and awkwardness of use.

There is a company selling online that makes a superior Faraday cage.   The company is registered with the International Traffic in Arms Regulations (ITAR) and only sell to organizations that are ITAR. The smallest item sells for well over $155.00 and measures about 9X10. That is considered their phone size cage. Definitely not pocket friendly and they are one of those bulky, stiff, items I mentioned earlier. However the manufacturer works hand and hand with federal accounts and insures his claims with independent testing.

Know the process

To start communication with a registered ITAR manufacturer, the buyer must also be registered with ITAR. The seller has nothing on their site with any information; everything is call for quotes. The site states that you must be ITAR and show documentation to communicate with them.

When a company purchases shielding materials to make a RF pouch from other manufacturers, the manufacturer of the materials should have done an intense study and stated those claims. Let’s say they claim to have a 90 dB attenuation rating. That ends when the reseller assembles the materials into a pouch. The product must then be retested.

I spoke with a few exhibiters at the CES Tradeshow that were displaying RF SHIELDING items. When I asked them the attenuation of the product, some could not answer that. When I asked if I could see the Independent Report, from a credited testing facility, they did not have one. I am always checking the competition.

Always ask a reseller for their “Certified Independent Test” results that proves the attenuation they are claiming    

Our SHIELDSAK is the most user-friendly and inexpensive cage for our attenuation ratings.   I hold the patent on the SHIELDSAK and I can tell you, it took me 5 years to come up with my fabric SHIELDSAK.

Our newest SHIELDSAK now claims to have 95% attenuation shielding effectiveness. Simply put, we offer one of the most effective and inexpensive cages in the marketplace worldwide.