Antenna gain for silicon IC

I have seen many papers with antenna gain for on chip silicon based antenna in negative dB values? Why is it so? How is the antenna useful without a positive gain?

generally because the antenna dimensions are only a tiny fraction of a wavelength (at the required freq) and therefore have 0 or less than 0dB gain


it still radiates, but not very well ... OK for very short range comms .... Bluetooth and other uses