Post subject: Can FR4 be used at 5.8GHz?
Fri Jul 08, 2005 1:43 pm
Does anybody have experience using
FR4 at 5.8GHz?
Unread postPosted: Sat Jul 09, 2005 12:33 am
Why not?. I
used FR4 upto 17GHz. No more RT Duriod.
Unread postPosted: Sat Jul 09, 2005
Mon Jun 27, 2005 2:02 pm
FR4 has a high loss due to its high TanD. Also FR4
has an unstable dielectric coefficient. That is working against
you if you have to implement printed elements: Couplers, Filters,
Baluns etc. The only motivation to use FR4 is only for low cost.
A known solution is to combine between 2 types of substrates: FR4
ROGERS 4003/4050 for example. In this solution, you can implement
the printed elements with the ROGERS and the rest of the design
Post subject: Thanks IR.
Unread postPosted: Mon Jul 11, 2005 12:53 pm
cost is what I am looking for. I am using FR4 with 10 mil RO4350
now. Two risks come with using FR4 only. One is whether I can build
power spliter/couplers/baluns on board. The other is will it have
too much loss. Is there any PCB supplier who are very experience
in doing FR4 PCB for RF application?
Unread postPosted: Mon Jul 11, 2005 2:14
Joined: Mon Jun
27, 2005 2:02 pm
I don't think that the manufacturer should be experienced in
doing FR4 for RF application. You should do the effort on a good
PCB layout and pay attention to good layout practices - and there
are plenty to follow.
Any medium to large PCB manufacturer
with good workmanship quality will do the same on your RF PCB. You
should ask the manufacturer to check the impedance of your PCB in
the layers that carry the RF signals. The manufacturer usually provides
a report of that test together with samples of the PCB.
you need more information, please let me know.
Post subject: Thank you IR
postPosted: Tue Jul 12, 2005 5:37 pm
Thank you IR!