Quick signal strength question

Obviously flexies have better range and are easier to get a read on because of their antenna size but comparing only glassies does the frequency generally make any difference? I have an access project that I could get working with high or low.

Range also depends on the reader and the amount of power it puts out. However, in my experience, the readers with the longest range are low frequency. So if range is a primary concern, go with an LF solution and test a few readers.

Some LF readers are terrible at reading glassies. Those often have a mediocre range with fobs, cards, etc…


Short answer:

  • Technically, yes.

If you don’t want the long answer, skip to the last 2 lines of the post.

Generally speaking, Lower frequencies travel much further, but with a slower time to cycle the waves. In our case, that translates into slower data transfer.

This is true for sound waves (you can hear bass sounds from farther away than high pitch noises)…
for Wireless internet (2G antenas are much slower but reach tens of miles while 5G might be fast but barely covers half a mile!)…

And in our case, RFID, where Lower frequencies can reach much farther than high frequencies.

In practice, though, It comes down to a lot more factors than just the frequency:

  • frequency: LF reaches further than HF
  • parity: the magnetic field formed is affected by the shape of the coil. similarly shaped fields (or fields which pair well) can usually be read from further away.
  • coil size: the larger the coil the larger the potential range of the magnetic field, but also the larger the blind spot created. There’s more to this bit, but that’s it in a nutshell.
  • Interference: LF is less affected by radio interference than HF.
  • power: the more power you run through the coil the larger the field will be, thus increasing range. this affects the following 2 items:
    • Active tags are read from further than passive tags. Implants are always passive.
    • A good reader makes all the difference since it’s the main active element.

There are a few more details, but I think that’s the core.
So a very good reader can read a HF tag from further than a bad reader would get a LF tag.

But given similar circumstances, LF should read from further away.

In practice, and mostly because the majority of readers you’ll interact with your implants tend to have squared or large circular antennas while glass implants have a “coil” antenna, we need to position the implants perpendicular to one segment of the antenna… which reduces this range a lot!

So in our collective experience I would say:

  • HF glassies tend to read from up to 1cm away
  • LF glassies tend to read from about 5cm away (sometimes more)

Wow! Thank you both. Great replies! :rat: