Which explains why it is functionally different to the printed antennae of modules such as the ESP8266 and NRF devices which share the same general pattern. 
Also why the latter antennae must not be located anywhere near any case metal or PCB.
Which explains why it is functionally different to the printed antennae of modules such as the ESP8266 and NRF devices which share the same general pattern.
Also why the latter antennae must not be located anywhere near any case metal or PCB.