Dielectric resonator - microwaves

[max201]

Hi,

recently there was an article in one scientific journal where they claimed that when microwaves are shined on a mixture of dielectric solid (powdered or crystalline) of high dielectric constant with some liquid, the EM field is much higher, both in the dielectric and in the liquid, as compared to the case of the same pure liquid. They also did some simulations (see the screenshot attached) where this is visible.

They give some explanations of the effect (microwave scattering, better penetration) but I'm not fully convinced. I have the impression that this is logically conceivable and explicable in terms of basic physics, especially for people who deal with microwaves. Have you ever seen an effect like this? Can you think of any analogy, a situation where this was previously applied? The microwave frequency was ~260 GHz here but I don't think that matters so much. Why does mixing two dielectrics with different dielectric constant will affect the one with lower dielectric constant in a way that it will "contain" more microwave field?

Thanks a lot for any ideas!

 

[mfb]

It would help to see the original article.

 

[max201]

Here you go. It's quite a specific application but the idea and results are described in the abstract.

 

[zoki85]

Interesting phenomenon. I guess it can be very useful but requirement of low temperatures and strong magnetic fields limit application potential considerably.

 

[max201]

Low temperature and high magnetic field are necessary for this particular kind of experiment (magnetic resonance, hiperpolarization) but I think the phenomenon of "confining" microwaves in a dielectric structure is much more general and applies to wide range of situations.. here indeed the wavelength is ~1mm which is shorter than typically used in communication.