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TRF7970A: RF-ID antenna design

yuki suzuki
Prodigy 10 points
Part Number: TRF7970A

Tool/software:

Currently, we are using this IC at NFC-V (ISO/IEC 15693) 26.7Kbps OOK.

"When designing an antenna, the application note, ""Antenna Design Guide for the TRF79xxA (Rev. C), on page 10"", states:
It is designed with Q=8.69. Is it correct to recognize that this antenna is designed to be used in all modes in which this IC can be used?"
Also, if it is used only at 26.7kbps, is it okay to design with Q=10~20 (bandwidth, 1.356M~0.678MHz)?

Is the bandwidth of the antenna sufficient to meet the bit rate to be used?

  • 0
    TI__Guru**** 191886 points
    yuki suzuki said:
    Is it correct to recognize that this antenna is designed to be used in all modes in which this IC can be used?

    Hi Suzuki-san,

      The Antenna guideline is for for all modes. If you only use ISO/IEC 15693, you can increase the Q factor. 

    yuki suzuki said:
    Currently, we are using this IC at NFC-V (ISO/IEC 15693) 26.7Kbps OOK.

    For an application that uses only the ISO15693 (NFC Type V) technology, the Q factor can be significantly higher, as the sidebands do not need such a wide bandwidth. A Q factor of up to 18 can provide great read range performance and should be considered the upper limit.

    Precise tuning is most important when creating a high-Q antenna for ISO15693, as the sidebands are cut off if the bandwidth is too narrow and the center frequency is off tuned, and that cutoff results in poor performance.