Electronic – Why does holding the car’s RF remote to the head extend its range

RF

I'm in my parking lot and just a little too far from my car for the remote to work… But if I hold the remote up to my chin, and then suddenly it works.

It sounds dumb until you try it, but it definitely works, with lots of different remotes/cars. I assume it has something to do with the capacitance of your head, but I don't understand the details.

Best Answer

This is just speculation. To confirm any of this would take some careful measurements with fairly sophisticated equipment.

Two things come to mind. First, just raising the remote should help with its range. Try holding it up at chin level but not near your head.

Second, it's possible that the length of your body is roughly resonant at the RF frequecy. By feeding the signal into your body antenna at one end and with the other end loosely coupled to ground your whole body might start acting like a antenna. With the transmitter at waiste level, your body antenna is center fed, which doesn't cause it to resonate as well. Again, this is all just speculation.