Microwave dielectric constant of Plexiglass

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

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

Real part of dielectric constant is 2.595 Imaginary part is 8.1 x 10^-4 x real part

At 10 GHz, from

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