Ultra Long Rate Antennas ALMA

Premo Nanotech Magnetic Materials Allow Long Flexible Emitter Antennae for Automotive Electronics.

The Alma™ Core Technology for Car Keyless Entry Systems saves installation, cables, electronic drivers and reduce component count with savings per vehicle over 100 USD.



The product is designed to be flexible and unbreakable thanks to a combination of Solid Echelons, Polymer Bonded magnetics and High Magnetic Permeability nanowires.

A Team of Scientist from Madrid CSIC ( Superior Council of Scientific Research), led by renowned expert in Magnetism Ph Dr Manuel Vazquez Head of the Group on “Nanomagnetism and Magnetization Processes” , researchers of UCIII Madrid , and a team of materials scientist and technologists at Premo Innovation Center in Málaga, have developed a Technology intended for LF emitter antennas in the range of 20KHz to 134KHz that over come the limits of conventional ferrite cores that are fragile and brittle and cannot be manufactured reliably in long forms. After 3 years of work and more than 1M€ in private and public funding the team is announcing the first industrial solutions of the new tech.


Metallic alloys of Fe, Ni , Co have been largely used for low frequency magnetic application thanks to their very high magnetic permeability (x1000 compared to ferrite) and their relatively high Magnetic Saturation ( x3 compared to ferrite). High frequency losses related to eddy currents have been relatively well managed in amorphous and nanocrystalline structures or in very thin laminated packs by layers electrically isolated from each other. None of these solution work for long flexible antennae due to magnetostriction an unwanted effect that produce significant changes in electric performance when the cores are deformed.

The production of amorphous an nanocrystalline nano-wires keeps both positive effects (high permeability and saturation) and avoids magnetostriction and losses by Eddy currents due to the extremely low cross sectional area and isolation. The Nanowires are distributed in a Polymer Bonded Magnetic matrix loaded with isolated ferrite nanoparticles as per Figure 0.


Fig. 0


Fig. 1 Fig.2 Fig.3


Existing solid single core ferrite antenna have to be installed around the vehicle (typically 4-5 per vehicle for a full coverage). Figure 1 shows radiation pattern of this so-called Short Range Emitter Antennas.

Recently, in a pressure to reduce performance and cost, automotive Tier 1 companies are designing systems with so-call Mid- range antennae , that still use solid long monolithic ferrite cores and increase reading range as per Figure 2 pattern. Nevertheless, those antennae may exhibit critical mechanical and reliability performance as the ferrite cores are typically longer than in Short range ones and flexion and torsion resistance drops significantly as per Figure 4.


Fig. 4


The solution developed by Premo -led researchers is fully flexible, unbreakable and can be as long as necessary. Three groups of international patents have been filed:

    • - Innovative Nanoparticle Polymer Bonded Flexible magnetic core ( Fig 0).
    • - Innovative High Permeability nanowires ( Fig 0).
    • - Innovative Ferrite Echellon Articulated constant gap Chain ( Fig 4.2).
    • - Automatic Process to produce long elongated antennae.


Link Ferrite Premo solution

Fig. 4.2


Ferrite core is then assembled to form a chain that is overmolded with PBM that keeps the product flexible and guides leakage magnetic flux along the core.



The airgap between echellons or core links is constant and the flux redirected inside the coil.


Fig. 5


The new AF series is presented in three standard lengths (AFS 322mm, AF 379 with center post for fixing on chassis with air gap to metal and AF ULR with 554 mm as per Figure 6)


Fig. 6

Field and laboratory tests shows that the AFS ULR configuration can generate signals with ranges over 30meters with 722mV/App/m sensitivity and generating a field at 3m of 123 dBµV/m opening the option to use is in Car to Car (C2C) long wavelength safety communication of short massages such as alarms or instructions in Platooning.

The product can reduce the number of antennas required in a Keyless Entry system from 5 to just 2 or even 1 with considerable savings in:

  • - Antennas costs.
  • - Wiring, installation, cable harnesses and connectors.
  • - Electronic drivers and amplifiers.
  • - Weight, space and component count.


Fig. 7


The product is designed to be waterproof IP67 with standard low cost EWCAP type universal connector integrated to ease installation, reliability and connectivity. The product has been qualified AECQ200 and is available with or without tuning resonant capacitor.



This family is compatible with most ECU reference designs from NXP like MPXY8300 family, TI, or Atmel (Microchip) like ATAK51004-V2 among other semiconductor manufacturers.

Mass production manufacturing process for antennae using this kind of flexible magnetic cores has been also developed and patented by Premo. The process handles the cores without damaging them, and also its able to wind enameled copper wire around it at high speeds, controlling pitch and winding window with automotive quality performance.

The ownership of the core technology and the process allows to Premo to offer a full set of solutions to the market. Additionally, fully customization is possible, a requirement coming as mandatory in most of the car brands. Electrical performance, field strength, mechanics, interface or field robustness can be fully customized, depending on the car segment, geographic area or market.

This kind of solutions are being qualified right now in major tier 1’s worldwide, being Premo a preferred supplier on key ones, with mass production launch on going for several specific part numbers.


PREMO is a Spain-based company engaged in the development, manufacture, and sale of electronic components with special focus on the key enabling technologies of the 4th Industrial Revolution: IoT, M2M, VR, Connected and Electric Vehicles. Our product portfolio includes RFID antennas (worldwide leader), AR/ VR Motion Tracking Sensors, power transformers, inductors & chokes, current sensors, EMC filters, and PLC components. In addition to our broad range of standard components (off-the-shelf products), PREMO also designs custom solutions to fit customer requirements, based on the latest technologies to help your systems be more efficient.

Over 1200 employees at 5 design centers and 3 production locations (Morocco, China & Vietnam), and an extensive sales network, let PREMO have a global presence in more than 36 countries to meet our customers specific needs.

We’ve been a preferred supplier for more than 56 years thanks to our strong commitment to business excellence, engineering support, reliable delivery and the quality of our products.