When multiple radios are supported in the same device, interference between the transceivers and the coupling between the antennas must be minimized. Radios can be isolated in frequency, time, and space. Polarization mismatch between antennas increases the isolation of the antennas.
The coupling between antennas on a shared Printed Circuit Board (PCB) can be minimized by choosing the least interacting antenna types and locating the antennas on the shared PCB so that isolation between the antennas is maximized. It is important to consider all the antennas of the device early in the design phase. Otherwise, for example, performance drawbacks in sensitivity or spurious emissions may occur. If the antennas are not sufficiently isolated, additional filters and switches may be needed in the RF paths to reduce interference. The nRF9160 LTE modem and Global Positioning System (GPS) receiver can be isolated from companion RF radios in time domain by COEX controls.