Why does the NFC range of an iPhone improve with an application

Question

I'm currently working on the NFC communication between an Apple iPhone 12 and an NXP NTAG 5 boost device (in active mode).

In order to better understand this behaviour, I am conducting range testing between these two devices. When I use the NFC Tools programme, I can easily reach 5 cm, however, when my iPhone is just unlocked, the range is barely 2 centimetres (I evaluate this range by gradually approaching my iPhone till it identifies the tag).

Could you specifically explain to me why this is happening?

Does the application turn on a setting that makes the iPhone more sensitive?

Does the iPhone have a capability that can be turned on to extend its NFC range without the use of an app?

Answer 1

I'm not familiar with iPhone, but I seem to recall reading about an analysis of the RF field on time with a suitable measurement kit in a post about Android. It was found that as the RF field's on-time and polling frequency increased, so did the detection range when an App actively asked the system to find a tag.

This was determined to be a power-saving function when no App was actively requesting that the system recognise tags.

This is likely the case with the iPhone as well, and it is a practical power-saving feature to use less power when there is a smaller likelihood that a tag will need to be read.