NFC Antennas

Micro Coil NFC Antennas

Micro coil NFC antennas have unique design – a coil with wires. We offer micro coil NFC antennas for sale and we also offer services of design and integration of the micro coil NFC antennas with various NFC controllers, tuning and testing of the antennas for your particular NFC products.

Micro coil NFC antennas are off-the-shelf NFC antennas that eliminate major considerations of planar NFC antennas – placement, layout and RF performance. Micro coil NFC antenna will not limit shape of your products. It would save effort required for antenna design and individual model modifications. It occupies in average 80% less space than NFC planar antennas and still it offers great multidirectional NFC performance. It reduces BOM, simplifies antenna tuning under the cover and lowers assembly costs.

Micro coil NFC antennas support active and passive modes and typically can be used in micro and metal covered objects.

Data Sheet Micro Coil NFC Antennas

Portfolio of micro NFC coil antennas

 

(Length x Thickness x Width):
18 x 1.385 x 3.14 mm coil
23 x 1.185 x 3.14 mm coil
25 x 1.685 x 3.14 mm coil

Note: Other sizes also available

 

We also distribute following coils

a. 9 mm x 0,93 mm x 0,785 mm
b. 18 mm x 1,73 mm x 0,785 mm
c. 23 mm x 1,73 mm x 0,785 mm*
d. 28 mm x 1,73 mm x 0,785 mm*

*mass production preparation is ongoing

 


Photo: 23 x 1.185 x 3.14 mm coil

Benefits
  • reduced size occupying approximately 80% -90% less area than conventional antennas with similar performance
  • great performance as it works stably and it transfer signals in all directions even in the presence of metallic materials which usually degrade the signal transmission quality of common antennas on the market
  • saving effort required for NFC designs and as individual model modifications as it is not necessary to adjust the arrangement of metallic components near to the antenna
  • reducing BOM by removing the ground plane and ferrite shielding
  • easy mounting as it has electrodes at both ends, the antenna is capable of reflow soldering and surface mounting, and thus requires no additional pin connectors. Micro coil antenna can be picked from a tape and directly placed on PCB
  • affordable price with reduced BOM, save up efforts on tuning, mounting and new design development for modified products this in total make the cost comparable with standard NFC antennas

Info Letter Micro Coil NFC Antenna

Typical Applications

Micro Coil NFC Antennas can be used in active and also in passive modes inside

  • smartphones and feature phones (EMVCo CE mode, R/W mode)
  • payment acceptance devices (R/W mode, EMVCo Power transfer)
  • secure microSD cards (CE mode) – for EMVCo NFC payments and transit, NFC secure access
  • SD cards (CE and R/W mode) – NFC secure access, pairing, flash memory locking
  • micro paying wearables – rings, watches, key fobs (EMVCo CE mode)
  • tiny devices with size limits to place standard NFC planar antenna – bracelets, glasses, earphones, speakers (pairing, secure access)
  • in any metal housing objects and complicated electronic environments; primarily used for Active Load Modulation (ALM), yet it can be also used for PLM – in NFC animal tags enabling reading from NFC mobile phone

Video Micro Coil NFC Antenna in Feature Phones

Video Micro Coil NFC Antenna in Metal Objects

Placement and Layout

Achieving satisfactory NFC performance in smartphones (CE and R/W modes) the micro coil antennas would save approximately 80% -85% from the area of conventional NFC antennas with comparable performance.  

Example 1 – Placement of original antenna (left) and micro coil antenna (right)
Example 2 – Placement of original antenna (left) and micro coil antenna (right)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Micro coil NFC antennas comparison with planar NFC antennas – Mobile phones
Comparison NFC Planar and Coil antennas

NFC planar antenna vs micro coil NFC antenna

Simplifying Design Work

The micro coil NFC antennas are tiny and it is not necessary to adjust the arrangement of metallic components near to them. Coil antennas are not much sensitive to the product’s casing. Coil antennas would limit steps needed to achieve matched and tuned NFC system and save effort for individual model modifications.
Because of its small size, multi-directional NFC performance and simple mounting – the micro coil NFC antenna can be placed in any part of the PCB
With the micro coil NFC antenna only general tuning for NFC controller is required; no additional tuning of individual product models needed

Assembling and reduced BOM

Unlike with planar NFC antennas ground plane and ferrite shielding are not needed.

The micro coil NFC antenna is SMT component that can be easily “picked & placed”. The coils are packed for delivery into reels.

With a few capacitors the micro coil NFC antenna can be tuned for the particular NFC controller. Coil antenna can be placed directly on PCB. As the coil antenna has electrodes at both ends, the antenna is capable of reflow soldering and surface mounting. It does not require additional pin connectors.

This makes assembly costs and effort lower compared to NFC antennas that are using external connectors or 3D structures.

Performance in metal housing objects

Planar antennas have limitations to communicate in metal covered objects.
Narrow but long rod ferrite micro coil NFC antenna emits the energy in the horizontal axis very strongly.

The intensity of the magnetic field reaches its maximum at the ends of the ferrite core. The below picture shows how the magnetic field passes through the narrow (0,05 mm) slits of the metal cover and gets back into the ferrite to be closed into loops.

Micro coil NFC antenna in metal housing – the emitting diagram

Video Micro Coil NFC antenna performance in metal objects

Electrical Features

Electrical features of the micro coil NFC antennas were measured on NFC antenna measurement system (using AWG Rigol, VNA OMICRON, oscilloscope Agilent)

We can provide antennas with other inductance value if it is recommended for particular NFC antenna products.

 

Influence of Metal

Coil antennas have stable performance in metal environment. Inductance of 9mm coil antenna when supplied with current of 100mArms in open air is 1,25µH while in a metal environment is 1,2µH
From approximately 3 mm distance between a metal plate and the antenna the influence of the metal on the antenna inductance is negligible, see 9mm coil antenna results in the graph below:

Properly designed metal housing may even increase the effectiveness of the antenna performance.

Production of coil antennas

We are ready to discuss micro coil NFC antennas mass production.

Contact our expert team to design micro coil NFC antennas customized for your
future NFC enabled products.

 

 

Contact us

Headquater:
Logomotion, s.r.o.

Winterova 15
921 01 Piestany
Slovak Republic

Phone: +421 2 544 355 45
Email: contact@logomotion.eu