Re: Maximum Power using FR4 board ?
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I found 50W of 1296MHz through a 50 ohm stripline on FR4 cooked the board and discoloured it over time. Why not use suspended microstrip with air dielectric, that would avoid the problem entirely at any reasonable power level.
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-------- Original message --------
From: John Worsnop <johnworsnop@...>
Date: 15/06/2019 08:28 (GMT+00:00)
Subject: Re: [UKMicrowaves] Maximum Power using FR4 board ?
So much depends on where the line is in the circuit, the dielectric thickness and the type of FR4. At RF, not all FR4 is the same! The thing is the the power density in the dielectric. The reason I used low loss RF35 in my 45W pa was the original FR4 version cooked the output line. In contrast, designs by Goran AD6IW I've seen work perfectly well at similar powers. That may of course just be a reflection on Goran's design skills compared to mine!
Stick to proper microwave materials for power if you can.
On Sat, 15 Jun 2019, 01:01 Gordon REASON via Groups.Io, <email@example.com> wrote: