It's in our brain
We receive signals from the outside world, and our tuning circuits tune into some of them, treating them as stimulus. Response and learning occur.
Our senses are transformers, that transform physical signals into electrical activity suitable for neuronal processing. (Sensors are the artificial equivalents of biological sense apparati.)
Our brain generates waves.
Does our brain include a receiver for brain waves? It may be able to detect other waves.
This would open the door for telepathy. Also, direct communication with other species.
In the mean time, we can use sensors.
Of course, somebody patented remote sensing.