[quarterwave]

The impedance of free space is (unfortunately) a few hundred ohms. On top of this, the minimum signal voltage of analog integrated circuits is set by unsystematic (random) offsets, which get worse as transistor sizes shrink. It's possible to mitigate these offsets by circuit techniques, but they cannot be eliminated.

Near-field radio can break free of the impedance constraint (which applies only to far-field TEM waves), but antenna area sets signal level, as in flux=intensity*area. Why make a tiny chip when the antenna needs to be the size of a quarter?

It's not easy to design radio chips for either of these scenarios. Pushing the radio burden onto the DSP consumes power on the digital side, so no easy way out.

[Aside: Referring to a recent thread on measurement of the Planck constant, the ratio of the impedance of free space to the Hall resistance turns out to be the dimensionless fine structure constant, alpha. This alpha sets the coupling strength of an electron and photon in the quantum theory of electrodynamics, and the 'Taylor series' for the self-energy of an electron converges because alpha is much less than unity. Feynman diagrams are a way to keep track of terms in that Taylor series, to ensure that the Schrodinger equation is kept consistent with special relativity, etc.]