NFC in smartphones
In recent years, NFC has become a more and more common feature in smartphones. The list of NFC-enabled smartphones is constantly growing. In this article, we seek to explain how the NFC technology is integrated into your smartphone.
The integration of NFC technology into your smartphone is realized by two components:
- NFC chip
- NFC antenna
The NFC chip provides your smartphone with NFC functions via an interface and is placed on the mainboard of your smartphone. Nowadays, most NFC chips in smartphones are produced by leading NFC chip manufacturer NXP. Apart from the NFC chip an additional NFC antenna is needed to power the chip.
During the production of smartphones manufacturers have to pay special attention to the placement of the NFC antenna. The position of the NFC antenna has a major influence on the quality of NFC communication, as for example the reach depends strongly on the correct placement of the antenna. In order to assure the common NFC reach of 1-4 cm the NFC antenna can be placed in one of the following ways:
1. NFC antenna on the battery cover
The antenna can be attached to the backside of the battery cover. Two contact surfaces and two pins in the device ensure that electrical contact between antenna and chip is established. The advantage of this position is that the antenna’s distance to the case cover of the smartphone is minimal. However, if a defect battery cover has to be replaced the spare part also needs an attached NFC antenna. Otherwise, the NFC function won’t be available any longer.
2. NFC antenna in the battery
Another option is to integrate the NFC antenna into the battery. In this case the battery establishes the electrical contact to the antenna and no additional contact surfaces and pins are needed. The main advantage of this position is that the battery cover can be easily exchanged. Nevertheless, a replacement battery needs an integrated antenna as well. A minor disadvantage is that the distance between NFC antenna and NFC tag is slightly higher because the antenna is placed deeper inside the phone than in the first variant.