The NFC Ring is by nature a more difficult item to read than a 'standard' tag or keyfob. There are a few things to remember:
- It will not work at distance the same way a "standard" tag will
- If it reads on any device you have then it should be fine. If it fails to read on one or some of your devices then the fault is most likely with those devices
- The normal or "Classic" sized band has a smaller antenna than the "Alpha" band and can in some circumstances be more difficult to read.
- Antenna matching is important in NFC. Your device having a bigger antenna is not necessarily beneficial. Having an antenna which is more closely matched to the size of the tag you are reading is.
Curvature of the inset inlay will probably affect readability but the thing most people are forgetting is that once the inlay is inset into the ring it's surrounded by metal.
This does have a pronounced effect on how the inlay works - if John and his team had not done the research and used an appropriately tuned absorber material beneath the inlay then performance would be like that of the GalaRing, next to unusable.
With the absorber material, the metal below the inlay 'appears' to the inlay to be further away than it actually is and thus interferes less with the function of the NTAG203.
So really, the three major differences between the rings and other devices are;
- Flatness
- Presence of metal
- Size of antenna
These all combine to make the NFC Ring difficult to distance read, this is known and understood and is a feature of the design itself, making the storage more secure.
With an NFC capable phone which is in perfect working order this is not an issue at all for readability, it merely means that you have to find the sweet spot and have it in perfect position for reading.
Unfortunately some phones have cheaply designed and implemented contact springs which can be damaged or make poor contact after even the slightest of knocks, they may have antennas which are far larger than necessary and are thus a poor match to the NFC Ring antenna.
This shows up more distinctly with the Classic ring than with the Alpha ring because the antenna in the Alpha is larger and thus more closely matched than the smaller Classic antenna.
In testing (under relatively controlled conditions, with a known good GS4) John and the team have confirmed that the Classic ring works even with a GS4, unfortunately mileage varies with your run of the mill phone out in the world because they are used differently, or possibly dropped/kept in a pants pocket on a hot day/any number of other situations that can aggravate the issues with matching by weakening the NFC field generated by the person's phone, and all without showing signs of damage on the outside.
So, generally if the ring works at all then it is fine and the issue lies either in the phone or in the expectations of how to use it. There can be some confusion due to the ease with which a 'standard' tag is used, you just swipe past the phone and boom done. With the ring there is a little more finesse involved and it can take time to figure out what works best for you with your device.
- A misconception I'm seeing/hearing of a lot more lately is that the 'signal strength' of the ring is some kind of variable value. This is a misunderstanding of how NFC works and has no basis in reality. The only way signal strength will vary is if the active device varies its output. The NFC tag is a passive device and is triggered by the active devices output. Covering the inlay of the ring with different materials will change how much of that signal can penetrate to the inlay but will not change the signal strength of the generated field. (This is what happened with carbon fiber, the fibers blocked too much RF and made them less sensitive to the generated field).
- This is why, if the ring works at all, any issues are more likely to be in the device generating the RF field.
