Interesting mathematical relationship
I have these CGY196 MMIC power amps, good for 1W at a few GHz.
I was flipping through the datasheet, and they give board layouts for various frequencies. And it sort of triggered that 'huh, what is the difference?' question in me. So I put 2 layouts next to each other:
And indeed, there IS no difference, Oh, but then there is: it is the board size!
So wondered what the relationship 'size change' versus 'frequency change' would be for those strip line things (could come in handy, I use different frequencies).
The frequency ratio here is: 2.4 / 1.89 (GHz) = 1.2698
Measuring those example board layouts on my screen gives 12 cm for the 2.4 GHz, and 13.5 cm for the 1.89 GHz board. Let's see: 13.5 / 12 = 1.125 .... not a LINEAR relations ship.
But number seems familiar, lets take the square root of the frequency ratio: sqrt(1.2698) = ???? 1.12685 Close enough to 1.125 to me :-)
So, for a given stripline layout, board size decreases as the square root of the frequency ratio.
Interesting, could have something to do with w^2.L.C=1