Please help identify the positive and ground for BLE antenna
The driven connection to the antenna is that fed by the series
component.
You will find on close inspection that the other terminal is ground.
It's not really correct to say that the driven terminal is &quot;positive&quot; as after the matching circuitry which will include a series capacitor somewhere, it will be an AC signal ranging both above and below ground.
More than a few antennas are actually a direct short to ground, where DC impedance is concerned, but still present appropriate impedance at the designed radio frequency.
Splicing on another sort of antenna or connection will have to be done with care, and it's not clear that the result will be compliant.