I need to place an EMI shield in front of a display but I'm not able to find out where I can buy a transparent EMI shield, in the form of a tape or a thin panel.
Is there a better wording for my searches? Does anyone know any product?
Try Googling for "ITO coated PET film"
The metal mesh in microwave oven doors is semi-transparent and works up to 2.4 GHz.
Does it need to be clearer than that?
Some military aircraft have a semi-transparent gold coloured canopy which looks like a thin metalized film on polycarbonate or acrylic. I'm guessing this is used for RF blocking but I have no idea how effective such thin layers are. Places that manufacture spectacle lenses have the equipment to deposit various semi-transparent metalic layers onto glass or plastic. Think mirrored sunglasses etc.
Before you can pick an EMI shield, you need to determine the maximum frequency you need protection from. That will tell you the opening dimensions allowed on the shield material.
Interesting requirement. Why do you need an EMI shield to go in front of a display?
I have to ask the same question as @er_name_not_found
Why do you need an EMI shield?
Is this for some old CRT display?
What is the problem you are trying to solve?
Have you tried various metalized ESD bags to determine how much transparency you need?
I'm using a Newhaven TFT display but it has some EMI issues (tested by certification lab). The manufacturer suggested to place a transparent shield on the front side of the display (as well as an aluminum plate behind)
You appear to be asking a hobby forum for advice on how to meet government regulations for a commercial product.
I suggest to have your product engineers research the topic.
I didn't asked "how to meet government regulations". I've just asked how a product is called...
Your product engineers could give you that information.
Does their support forum have the answer? Is the display creating the EMI or just allowing it to pass through? Seems like your lab person does not know the source of the EMI, but only detects it. Did you find any EMI before taking the project to the lab?
I wrote to the technical support and they suggested to use that type of shielding.
Yes, it is the display. I also detect it using a cheap spectrum analyzer and removing the power from the display cancel out the EMI peaks.
Good test! If the EMI repetitive or totally random? I suspect it is related to the display controller scanning the display, which you cannot stop! Does the project enclosure stop the EMI, except from the front of the display?
They are repetitive and stable. One main peak at 120 MHz and others at higher frequencies.
Unfortunately the device's enclosure is made of plastic and does not stop the EMI.
Get a spray can of metalized paint for EMI reduction and spray the inside of the enclosure. That has been done for as long as plastic has been used for enclosures.
Yep, but since there is a WiFi transceiver inside (ESP32) I'm afraid it can prevent the connection. I should use an external antenna, but is not possible.
Mask off a strip of paint and use that for the antenna!
You might want to search for "transparent conductive film", "EMI shielding film", or "ITO film" (Indium Tin Oxide film)—these terms are commonly used for transparent EMI shields used in front of displays. Some products also go by names like "EMI shielding mesh" or "conductive adhesive tape (transparent)".
Companies like 3M, PPG, or TDK often offer these kinds of materials. You could also check electronics suppliers like Digi-Key or Mouser.