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Original question:

CC3135MOD: CC3x35MOD patch approved Antennas

CC3135MOD: Antenna replacement by similar part

Antoine RADET
Prodigy 20 points
Part Number: CC3135MOD

Dear Support team,

Yageo ANT5320LL04R2455A antenna is listed in the "CC3x35MOD approved antennas" list.

Unfortunately, this part is no longer available (no stock, no longer referenced on the manufacturer's website).

However, Yageo has a very similar part : ANT5320LL24R2455A

If using this antenna as a replacement part, do you confirm that no additional certification is required (except for Japan)? As explained by Seong Tim's in "CC3135MOD: CC3x35MOD patch approved Antennas" thread : "you can use any antenna as long as the gain does not exceed what is shown on that list. And this is done by type."

The gain for these antennes are as follow : 

  • ANT5320LL04R2455A
    • 2.17 dBi @2.4 GHz ; 3.51 dBi @5 GHz (as per TI's SWRU549, Table 1)
    • 2.09 dBi @2.4 GHz ; 4.32 dBi @5 GHz (as per Yageo's datasheet)
  • ANT5320LL24R2455A
    • 2.17 dBi @2.45 GHz ; 3.51 dBi @5 GHz (as per Yageo's datasheet)

Many thanks

  • 0
    TI__Mastermind 28285 points

    Hi Antoine,

    If the gain and out of band characteristics are the same, its likely this can be supported. I would suggest reaching out to your test house for confirmation.

    BR,

    Vince 

  • 0 in reply to Vincent Rodriguez
    Prodigy 20 points

    Hi Vincent,

    Thank you for your prompt reply.

    Do you have any criterion to assess the degree of similarity in out-of-band characteristics?

    Though both antennas characteristics look quite similar (see return loss diagrams below), the proposed antenna (left image) performs more poorly between 3.6 GHz and 4.8 GHz than the reference one (right image).

    Many thanks

    Antoine

  • 0 in reply to Antoine RADET
    TI__Mastermind 28285 points

    Hi Antoine, 

    It will be at the descretion of the test house, so I can't give you a straight answer - But what you'd want to take a look at our current reports and see if what our margins were at for out of band emissions and ensure if you used this antenna you wouldn't fail. for example if we had a 2dB margin, but the new antenna out of band is 3 db worst, we could possibly fail by 1 dB. These are things the test house would be checking for.

  • 0 in reply to Vincent Rodriguez
    Prodigy 20 points

    Hi Vincent,

    I could not find a report with detailed test results using the different antennas.

    On the FCC website (https://fccid.io/Z64-CC3135MOD), all tests seem to be performed with the Ethertronics antenna (most reports state : "The EUT used a dual-band chip antenna (Antenna 3 from Ethertronics)").

    Could you provide a link to a report with individual test results?

    Many thanks

    Antoine

  • 0 in reply to Antoine RADET
    TI__Mastermind 28285 points

    Hi Antoine, let me get back to you in 2 days - looking into the answer.

  • 0 in reply to Vincent Rodriguez
    TI__Mastermind 28285 points

    Hi Antoine, We only have the test data on the Antenna on the Launchpad. Other's can be added based on the initial certification, similar to what i outlined above.

  • 0 in reply to Vincent Rodriguez
    TI__Mastermind 28285 points

    Hi Antoine,

    Here is some additional info: 

    Unfortunately, what I outlined is how the certification process works for our devices. We will certify our device once with a specific antenna, then the rules state as long as the antenna doesn’t change the gain or effect RF performance then you can add it to your reports. If the RF performance changed (more Gain on ANT), this would trigger a Class 2 permissive change, and we would then have to recertify. We don’t go down that route, and advise customers if they want to reuse the modular certification, they need to use one of our recommended antennas or similar performing one. Also, when this happens and customer have to use a different antenna, we advise customers to do the Change In ID/Multiple Listing to take our test data and then perform any delta testing to certify their new antenna on their filing.

     

    The area of “Similarly” performing antennas I admit is a grey area, but the reason is because it’s at the discretion of the test house and certification Body (FCC,CE,IC) to determine, not TI. We can’t say 100% a similar antenna will be allowed, because you could get different answers depending on what test house and region you are looking to certify in.

    BR,

    Vince