(From the original file sent to Doug. Due to popular demand) I'm not a designer but a fabricator in charge of what I call "bleeding edge". My experience with RF and FR-4 leads me to believe "you can't get there from here". I've heard of transceivers with multilayer PCBs going to 6 and 8 Ghz, but these guys are pros. Microwave gurus who plug their designs into SPICE for 2-3 wks before they build protos. They acquire the protos and take readings that they plug into their SPICE library. (Constantly gaining real data) If their far off, they tweak and build new protos until they get it. The cost of 2 or 3 proto builds still is not as steep as PTFE multilayers. Their is new materials out there that are targeted to fill the RF gap between PTFE and FR-4. Starting with a Er of 4.2, One of the PTFE manufacturers now has a rigid mat'l with a low Dk, A new continuous laminate manufacturer is making something that looks very promising at Er 3.3. The only problem is that these materials generally are only available in a few thickness'and prepreg is not yet available and we have to use something different to bond them together. Let me know if you get some resolution or design related suggestions. I like to stay current with this kind of stuff. Dave Hoover (Groovy) (This post has been modified from it's original text so that everybody else can see the direction of the response. <Leaving vendors names off>) ______________________________ Forward Header __________________________________ Subject: PC Board Frequency Limits Author: [log in to unmask] at SMTPLINK-HADCO Date: 5/7/96 10:09 PM I would like any responses to be off-line for the following discussion. Please use the following email address: [log in to unmask] I made a simple mathematical model of a stripline, 1 inch trace, on FR-4, nothing out of the ordinary as far as dimensions and found to my surprise a resonant freq at about 800 MHz with a 20 to 40 dB roll-off above 800 MHz Could someone in the RF/Microwave world of nuts and bolts pc board design tell me what I'm supposed to do at say 10 GHz with regular pc board materials/construction/fabrication??? Thanks in advance, Doug McKean