1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Penetration depth of a microwave

  1. Aug 5, 2016 #1

    according to http://www1.lsbu.ac.uk/water/microwave_water.html and other sources the penetration depth of a microwave wave is proportional to the square root of the dielectric constant divided by the dielectric loss. For me it makes sense that as the dielectric loss increases more energy is being converted into heat and penetration depth is smaller but why does the penetration depth increases with an increase in the dielectric constant if more electromagnetic energy is being absorbed by the medium?

    also, another question, what is the physical meaning of a material that has a high dielectric constant and low dielectric loss? what is happening to all the energy that is being absorbed if it is not being released as heat?

    thank you for your replies
  2. jcsd
  3. Aug 5, 2016 #2


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    Absorbed energy has to be transferred as heat but the field can be reduced without dissipation - it is just redirected back out. The complex permittivity has a real and imaginary part and it is the imaginary part that is responsible for energy loss.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted