Information about the loss tangent of FR4

[joshuacp]

Hi, all. These days I've been reading Kin-Lu Wong's book,

planar antennas for wireless applicaitons, I was confronted

with a question. In this book, lots of printed antennas are

printed on FR4, the relative permitivity and the hight of the

substrates have been given, but the loss tangent of the

substrate hasn't been given. Could anybody give me some

information of the loss tangent of FR4?
Thank you very much in advance.

 

[boy]

tand fr4

0.04. I saw it somewhere

 

[Black Jack]

fr4 permitivity

FR4 loss tangent is 0,012 - 0,019

 

[Manjunatha_hv]

loss tangent of fr4

Hello

It is not 0.04 it is 0.014

http://www.rogerscorporation.com/mwu/tip12.htm

Black Jack is correct it varies from 0.012 - 0.019

--manju--

 

[nauwaf]

tand of fr4

hi the FR4 tand at 3Ghz is 0.02 and Er is 4.3 at 3GHz (note that Er is 4.7 at low frequencies only) some thing else FR4 is note built for high frequencies.

 

[sergio mariotti]

fr4 er tand

as told many times, FR4 don't identify totally the compound. many FR4's may be different between them.
As rule of thumb i've measured a tand=0.02 +/- 0.003 at 0.5...2 GHz
What is important, is not the exact value, but the fact that is ten times the tand of a Roger 's laminate.

 

[g579]

fr-4 tand

I confirm that in 0.5 - 2 GHz range the loss factor is about 0.02

 

[joshuacp]

fr4 loss tangent

Thank you above very much.

 

[elek_fyc]

fr4 tand typical

For Alumina you cn use 2.10-4 as a common value.