One basic point to keep in mind here is that in dielectrics the wavelength of radiation can be many times shorter than in freespace - up to 20 or 30 in some cas

One basic point to keep in mind here is that in dielectrics the wavelength of radiation can be many times shorter than in freespace - up to 20 or 30 in some cases. So if you have some system that is too small to set up the resonances you would need for an antenna you can put it in a dielectric with a high K value and the resonances will all be shifted to higher frequencies. It looks like there's an interesting bit of analysis in here, but that basic concept is as as old as Maxwell. As for gigahertz antennas on a chip... well, you all probably have one in your pocket :)