Miniature NFC Antenna

LGM antenna is a miniature NFC antenna that has patented design representing new perspective of miniaturization of NFC antenna circuits. Miniature NFC antenna (LGM antenna) is solenoid, ferrite antenna in a shape of a miniature rod with ferrite core.

LGM antenna can be used with various NFC controllers – products of 3rd parties.

LGM antenna is ideal for size-critical, metal covered objects with needs for contactless communication at 13.56 MHz. Despite its tiny dimensions it works also if surrounded by metal or in complicated RF environments.

Unique features

Tiny dimensions

Compared to standard NFC planar antennas with sizes about 15x15mm, LGM antenna sizes are much smaller measuring only Length 9 mm x Width 0.93 mm x Thickness 0.785 mm.

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Performance in metal housing objects

Planar antennas have limitations to communicate in metal covered objects. Narrow but long rod ferrite LGM 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.

LGM Antenna in metal housing – the emitting diagram

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

Performance in smartphones

LGM antennas can be manufactured in bigger sizes so they can be used in NFC modules supporting all NFC modes – e.g. smartphones.

In addition to small dimensions and performance in metal housing, LGM coil antennas can eliminate material usually needed with planar antennas (high permeability sheet).

LGM antenna does not limit smartphone designers – due to its small size, higher placement variability and lower tuning complexity.  

It also increases user’s convenience as the tap of the phone is possible from any side of the phone.

Comparison of standard planar antennas and coil antenna

screen-shot-2018-10-18-at-16-08-38

 

 

 

Technical characteristics

LGM Antenna Design

LGM antenna is a solenoid, ferrite antenna in a shape of a rod with miniature ferrite core.

A rod shape of the LGM ferrite antenna

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Exceptionality of the design

  • the smallest compact antenna on the market
  • replaces the planar antenna in ALM mode
  • can be implemented in Card emulation and Read/Write mode
  • has been tested with ALM NFC controllers from 3rd parties
  • can communicate well from metal housing; properly designed metal housing may even increase the effectiveness of radiation

LGM Antenna Electric Features

Specification 

Part Number Inductance –

current 100mAp

Rated current Tolerance

from fab

Q – quality

Current 100mAp

Self-resonance
Open air Metal environment Continues current Up to 1s
A.6.21 1,25µH 1,2µH 100mArms 250mArms 5% 15 90MHz

*from approximately 3mm distance between a metal plate and the antenna the influence of the metal on the antenna inductance is negligible, see picture below

 

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Basic Characteristics

  • Small size at L:9 x W:0.93 x T:0.785 mm
  • High magnetic field strength
  • Applicable to reflow soldering
  • RoHS compliant

Supported standards

  • ISO/IEC 14443 Type A, B (up to 848 kbit/s) with Active Load Modulation
  • NFC Forum compliance
  • FeliCa with Active Load Modulation

Supported NFC controllers

LGM antenna can be used in both CE and R/W mode. For CE mode, the best results can be achieved with NFC controller supporting active load modulation.

 

Applications

LGM antenna is mainly suitable for:

  • miniature mobile devices enabling CE mode, for NFC pairing of BT devices and WiFi setting, for reading tags (R/W mode)
  • tiny devices with size limits to place standard NFC planar antenna, for example small wearables and accessories (rings, bracelets, glasses, watches, earphones, speakers…)
  • solutions, where the metal housing or complicated electronic environment does not allow NFC communication, for example touch panels, displays, in automotive industry – car audio systems, in machines – to control and manage production processes in factories etc.

LGM antenna application examples

Contactless smart microSD (LGM Card) – a commercial product

Miniature NFC module – a prototype

The smallest NFC module supporting CE and R/W mode with dimensions L:16,5mm, W:10,9 mm and thickness of 1,7 mm occupying 180mm2 area in total.

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Block Diagram of NFC module using NXP PN80T

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Main Characteristics of NFC module using NXP PN80T

screen-shot-2018-10-04-at-13-48-42

Availability

We provide LGM antenna samples on request. You can test LGM antennas performance via LGM antenna modules.

LGM antenna modules are printed circuit boards (PCB) comprising LGM antennas with matching circuits tuned for particular NFC controller (product of 3rd party). NFC Controller is not part of the LGM antenna module.

LGM antenna module is connected via pin header connector to the EVB board of particular NFC controller vendor. We provide Manual  for testing.

6                                                                                    LGM antenna module connected via pin header connectors with NFC controller NXP PN80T EVB

To get EVB of NFC controller contact NFC controller vendor.

LGM antenna modules available

Antenna Module # LGM Antennas Supported Modes Default configuration for

NFC controller EVB / vendor

Module Interface Analog
LGM AM_RW&CE 2 R/W, CE PN80T EVB, PN553 EVB pin header connector
LGM AM_CE 1 CE PN80T EVB, PN553 EVB pin header connector

7                  8                                        LGM Antenna Module R/W               LGM Antenna Module CE

See Demo

We offer

  • Purchase LGM miniature antennas
  • Purchase LGM antenna module PCB for easy testing of LGM miniature antennas
  • Performance optimization for your products using LGM miniature antennas
  • Feasibility testing of LGM antennas with NFC controller by customer’s choice
  • R&D support for your individual projects

All LGM antenna modules are tested in SMK-LOGOMOTION on certified testing devices and reference NFC antennas to meet EMVCo, NFC and MONA tests criteria. Performance test results are available for download.

Download

For more details, pricing and availability:

Contact us