We will design customised secure microSD cards and micro coil NFC antenna systems

We will develop and produce tailored secure microSD cards based on your specification.

We will help you with selection of the micro coil NFC antenna size and NFC antenna module specification, design and tuning. We can make prototypes NFC antenna modules tuned for your NFC products using particular NFC controller and SE – respecting your choice and the best performing NFC solution.
We have developed various combinations of micro coil NFC antenna modules. These NFC modules passed EMVCo (CE), MoNA and NFC Forum Power transfer (R/W) criteria in various environments – plastic, glass or metal.


We will basically provide:

System analyses, micro 
coil NFC antenna selection

  • Navigating in NFC standards
  • Customer’s schema review
  • NFC performance simulations
  • Performance requirements and miniature coil NFC antenna design options

NFC antenna
system design

  • Mechanical and electrical feasibility
  • Creating specifications from user needs and compliance requirements
  • Design of NFC antenna system
  • Simulation, prototyping, matching – for particular customer’s product
  • NFC performance measurement reports
  • NFC CE – EMVCo pre-compliance testing

NFC antenna
integration support

  • PCB review
  • Final PCB matching
  • Mass production process tuning
  • Mass production testing development

Secure microSD cards

  • End-to-end projects starting from customer’s needs review, design, testing up to a mass-production
NFC antenna design selection

We recommend to use micro coils in one of two basic designs:

  • A single antenna design uses one coil antenna for both RX (receiving) and TX (transmitting). Choose the size from our portfolio
  • Dual antennas design uses one coil as RX antenna and the second coil as TX antenna (to improve the isolation). For NFC controllers with very low isolation or to reach a specific criterion the coil used as TX antenna can be substitute by a miniature planar antenna.


PCB examples – Micro Coil NFC Antenna Modules

Typical Applications

Micro coil NFC antennas address various applications:

  • smartphones and feature phones (CE and R/W modes)
  • secure microSD cards (CE mode) and SD cards (CE and R/W mode) – for payments, transit, pairing, flash memory locking
  • miniature paying wearables – rings, watches, key fobs (CE mode)
  • tiny devices with size limitations 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

Mobile phones

One coil NFC antenna design starting with coil sized L:18mm x T:1,4mm x W:3,14mm fulfills performance criteria in CE and R/W mode as well as NFC criteria for mobile phones working as acceptance devices *

Supported standards

  • ISO/IEC 14443 Type A, B, F (up to 848 kbit/s) with Active Load Modulation (ALM)
  • Compliant with NFC antenna performance requirements (RW mode) for India*: Power transfer at 0 and 1 cm in a position A – must pass both distances and in the rest of positions – B0, C0, D0 and E0 it must pass 2 out of 4 distances including card operation distance for DESFire EV2 tag – 18mm
  • RoHS compliant
  • NFC CE (EMVCo) and R/W mode (MoNA)

Micro coil NFC antennas comparison with planar NFC antennas – Mobile phones

Communication distance in R/W mode – example under metal

LMA in EMVCo volume (extended to 6 cm) – examples of selected coils with PN80T

RW mode performance – examples of selected coils with PN80T

Power Transfer Results

Communication distance with DESFire EV2 NFC tag

Miniature Paying Wearables

For miniature and metal paying wearables that contain a battery (e.g. NFC watches, key FOBS, rings, etc.) we recommend to use the smallest single coil antenna design (RX/TX), supporting NFC CE mode. For wearables without a battery we have patented solution using two miniature coil antennas that support a passive modulation.


  • NFC payments, secure access

Supported standards

  • ISO/IEC 14443 Type A, B, F (up to 848 kbit/s) with Active Load Modulation (ALM)
  • ALM and PLM
  • RoHS compliant
  • NFC CE (EMVCo)

EMVCO– NFC CE Level 1 result of 9mm antenna tuned for NXP PN80T and placed under metal; tested on FIME test bench:

Tiny devices

For luxury or miniature metal wearables with or without a battery and with size limits to place a standard NFC antenna – e.g. NFC enabled watches, bracelets, glasses, earphones, speakers, key FOBs, rings, USB dongles etc.; we recommend to use the smallest one coil antenna design (RX/TX), supporting NFC peer-to-peer mode.


  • pairing, secure access

Supported standards

  • ALM and PLM
  • RoHS compliant
  • NFC CE (EMVCo)
  • ISO/IEC 14443 Type A, B, F (up to 848 kbit/s) with Active Load Modulation (ALM)

Communication distance in CE mode – test example under metal

NFC USB Dongle
Miniature NFC coil antenna can be embedded inside NFC USB dongle (see a prototype on the picture) and that will be connected to a mobile phone or PC/notebook – adding them a functionality of an acceptance device (merchant device).
NFC USB dongle can be attached to PC/notebook and support a multi factor authentication. It can comprise SE that generates, stores and protects secure keys and certificates and performs cryptographic operations and store other sensitive data (passwords, logins, user’s identification etc.)


  • Payments acceptance
  • NFC tags reading
  • HW token and multi-factor authentication enabler

NFC USB Secure dongle usage examples

Supported standards

  • ISO/IEC 14443 Type A, B, F (up to 848 kbit/s)
  • RoHS compliant
  • NFC CE and RW (India criteria)


NCF enabled microSD card
Micro coil NFC antenna can be embedded inside microSD card or SD card. A standard size microSD memory card has a single 9mm built-in micro coil NFC antenna and one or two embedded secure chips (see picture LGM Card).


  • payments, pairing, flash memory locking
  • secure NFC access and control for IoT and electronic vehicles

Supported standards

  • ISO/IEC 14443 Type A, B, F (up to 848 kbit/s) with Active Load Modulation (ALM)
  • ALM and PLM
  • RoHS compliant
  • NFC CE (EMVCo)

LGM Card (NFC secure microSD card is certified by NPCI India from July, 2019 – LoA and it was certified by MasterCard in 2014 – LoA.

Industry metal housed objects

The coil NFC antennas perform also in metal housing objects and in a complicated electronic environment.


  • Machine setting, locking or pairing over NFC
  • secure NFC access and control for IoT and electronic vehicles
Secure microSD card design

We will help you with technical specification, design, prototyping and mass production of secure microSD cards and NFC secure microSD cards.

We will help with Flash controller firmware specification and development, we will tune the production process and mass production testing tools directly with the production factory. Our know-how also covers:


  • Existence of two mutually interconnected Secure chips (SE). We have experience and know-how with implementation of secure chips from various vendors into the microSD card. These vendors include Infineon, Gemalto, Kona I, NXP, Idemia or STM.
  • Contact interconnection between the SE that enables contact interaction within an SD card – there are more use-cases enabled and that are subject of patent protection.
  • Unique antenna design enables reception and the emission of radio signal for contactless communication – there are more patents granted and filed for the micro coil NFC antennas. Based on your specific needs we offer design, testing, prototyping and mass production of customized miniature coils.
  • microSD card multilayers design enabling concentration of all necessary hardware components on microSD card body – we have experience with co-operation the best established microSD card production factories based in Taiwan. Based on our know-how and contacts we are able to discuss a specific production needs and customized testing.
  • External contacts on the bottom side of the microSD card in accordance with ISO7816 standard. This kind of design enables to personalize the microSD card inserted in ID-1 size plastic carrier on existing personalization machines or via a standard contact reader. Our know-how and co-operation relations with Flash controller vendor enables us to design a customized firmware of the Flash controller that will answer your specific design needs. Using ISO 7816 contacts on the microSD card surface are subject of our patent protection.
NFC performance measurements

We have tested micro coil NFC antenna modules performance with various NFC controllers.

We have developed a specific measurement method for simulating micro coil NFC antennas performance in smartphones. We can compare NFC results of these micro antennas with NFC results achieved by the same original reference phones. Each measurement is performed in 5 positions – backside, display, up, left and right.

We use FIME Automatic RF test bench for EMVCo Level 1 Analog test.
For R/W mode performance we use reference MoNA tags and NFC SONY reader RC-S380.
We have experience from certification of the NFC secure microSD cards as a mobile payment product performed at FIME France and FIME India.

Contact us

Logomotion, s.r.o.

Winterova 15
921 01 Piestany
Slovak Republic

Phone: +421 2 544 355 45