antenna design

[ben]

Hi, I use NRF51822 to design a ble product,my client require that when in the front of the ble device the app can connect the ble device,and can't connect in the back of it.is it possible to design a antenna that in the fornt of the ble device there is RF signal,and no RF signal in the back of it?such as outside the door I can connect the ble device with app but not inside the door.
Best regards.

[Janek Mann]

No, that's not possible. RF doesn't work like that, even if it were possible to design such an antenna (it's not in practice) the signal would get bounced back from any nearby surfaces.

[ben]

ok,thank you very much for your help.