Microwave dielectric constant of Plexiglass

Dear experts,
does anybody know about the (complex) microwave dielectric constant of plexiglass in the frequency range from 10 to 100 GHz? Or where may I find information on this?
I'd be happy about any useful comments,
best regards,
galaxor.

galaxor wrote:
  Quoted Text Here  
I did actually characterize 'Plexiglas' for microwave applications. Not to 100 GHz though and it was some 20 years ago so I have to dig deep to find numbers.
This kind of characterization isn't *very* hard to do provided that you have measurement instruments covering the frequency range of interest. What you need to do is to adapt the procedure described in the following reference.
M. Olyphant & J.H. Ball: "Strip-Line Methods for Dielectric Measurements at Microwave Frequencies" IEEE Transactions of Electrical Insulation, March 1970, pp 26-32

galaxor wrote:
  Quoted Text Here  
You can do searches on acrylic, polymethylmethacrylate, and PMMA (different names, same material). I think Lucite is also the same stuff.
For acrylic @ 100 GHz, from http://www.ovro.caltech.edu/~lamb/ALMA/Receivers/mmMaterialProperties1.pdf : Real part of dielectric constant is 2.595 Imaginary part is 8.1 x 10^-4 x real part
At 10 GHz, from http://www.loqnl.ufal.br/publications/2002/artigo32002h.pdf Dielectric constant is 2.59 (no mention of imaginary part), and they refer to: AIP Handbook, 3rd ed., edited by D. E. Gray ~McGraw-Hill, New York, 1972, Sec. 5, p. 132.
Hope that's a useful start.
Mark