Iphone activates my cars alarm

I just started noticing that my iphone activates my cars alarm everything I get close to my car, I carry my iphone and car keys (with alarm remote) in the same pocket in my jacket. It's not a big deal, but has anyone else experience this before?

What car do you have? I've heard of phone interfering with key fobs before. Most notably Nissan, where a phone would essentially wipe a key fob's memory and you weren't able to lock/unlock the car with the fob anymore and needed to get the dealer to flash the fob's memory.

National Rental car told me very clearly before they gave me the keys to a Nissan Maxima to NOT keep the key near my cell phone or it would wipe the key fob and i would be stuck. it was nice to know cause i was going to a good distance away from anything