Key Detecting Antennas

[maractwin]

I was writing yet another response on a different thread about poor unlocking performance, trying very hard not to sound whiny while asking some questions about why this works for some people but not others, when I think I figured out why my usage pattern leads to the car often being slow to unlock. I nearly always approach from the back. That is not going to change. So for me to have a better experience, the car needs to be better at detecting a keyfob when I am right behind the car.

Several people have said that the car is bad at detecting key fobs or phones approaching from the rear. So how can I change that? I’d like to add an aftermarket antenna, maybe to the rear deck or the license plate frame, that makes the car better at detecting a key behind the car.

Where are the current antennas located? Do any of them have a coaxial cable connection to the car electronics, such that a different antenna (or more than one) can be plugged in there? Do we know what band the keyfob broadcasts on, for designing a new antenna?

 

[DeaneG]

My expectation would be that the Air has several integrated key radio modules in different places in the car, with only digital output, maybe canbus to a nearby gateway to the car's Ethernet ring.

The back of the car is definitely the weak spot for the fob. Can't speak for the mobile key.

I'm any event, you can't just add antennas of the same frequency band to a common coax cable. Multipath effects will result in spatial nulls around the car, for example where one antenna receives a key's signal and another receives it 180 degrees out of phase, cancelling the net signal.

You need one radio per antenna to avoid this.

 

[Steve181]

I would love to see a wiring diagram and more technical info for the car including: antenna locations. Also, cabling of the computer into the large screen in the front. Also, how the key fob works.

 

[Pragmatic]

Good luck with that, as even something as simple as a cabin air filter is only available from Lucid.

 

[knewman]

I'd be surprised if antenna design or signal range was the issue. On more than one occasion my phone has connected to the car via Bluetooth and started playing audio through it while parked in the garage - I'm two stories up through many walls. I'd be impressed if it wasn't such a dumb problem to have.

An office building I frequent uses the same Bluetooth technology to let us unlock external doors with our mobile devices, the failure rate we see with that system is about the same as what I see with the car. Bluetooth is just not a very good protocol for use as a key fob.

 

[newlucidguy]

my prior car was bad from the back as well. the antenna was near the infotainment and there's just a lot of metal between the infotainment and behind the car. not sure where the antenna is in the Air. but, I don't think the problem is unique to Lucid fwiw.