Garage door opener antenna

[petersk]

Does anyone know details of the antenna used in the model 3 for opening/closing the garage door? I think it is on the driver’s side, but I was wondering its orientation and, thus, Polarization. Any details would be appreciated— model specifications would be awesome as well.

kurt

 

[Gauss Guzzler]

The Homelink module is mounted front-center just ahead of the hood latch on the 3, but off to the left on the Y.
It features an integrated PCB antenna shown in the last pic (L-shaped trace) which looks to me like circular polarization.

I can't imagine why you would want to know that though.

 

[petersk]

The Homelink module is mounted front-center just ahead of the hood latch on the 3, but off to the left on the Y.
It features an integrated PCB antenna shown in the last pic (L-shaped trace) which looks to me like circular polarization.

I can't imagine why you would want to know that though.

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[Gauss Guzzler]

*Correction* The antenna appears to be a simple "bent monopole" in which case it would be mostly linearly polarized and horizontally so in this case.

I'm now curious why they would choose horizontal polarization considering that a vertical monopole should have a more suitable radiation pattern and many openers have dangling wire vertical antennas. This module is also used in modern Audis but I couldn't find a pic of the mounting orientation - probably because Audi's just include the module so no one ever needs to mess with them.

 

[petersk]

*Correction* The antenna appears to be a simple "bent monopole" in which case it would be mostly linearly polarized and horizontally so in this case.

I'm now curious why they would choose horizontal polarization considering that a vertical monopole should have a more suitable radiation pattern and many openers have dangling wire vertical antennas. This module is also used in modern Audis but I couldn't find a pic of the mounting orientation - probably because Audi's just include the module so no one ever needs to mess with them.

That is PRECISELY why I asked the question. Mine dangles nicely vertically from the opener.

 

[Gauss Guzzler]

Most modern cars use a Gentex mirror with an vertically oriented internal Homelink antenna, but cars with it in the visor or center dome light assembly use horizontally oriented antennas. Even the old visor clip-on openers were generally horizontal.

So apparently it doesn't make much difference. You get a little better ground-reflection properties with the horizontal polarization and maybe that's enough to mitigate the mismatch loss.

If the Homelink module is mounted with the label text right-side-up it will have vertical polarization but Tesla chose to mount it sideways for whatever reason. I'd bet it's because it works well enough horizontally, the horizontal wiring works better with the bumper structure/airflow and the horizontal connector is less prone to water intrusion.