Re: Microwave PCB design
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Is the quadrant not a capacitor?
On Tuesday, 21 September 2021, 15:16:35 BST, Robin Szemeti - G1YFG <robin@...> wrote:
They are a 1/4 wave choke ... the track leading to it will be as thin as possible, to be as inductive as possible, the radius of the arc is 1/4 wave, taking into account the propogation velocity of the substrate.
A quadrant arc allows them a point contact on the conductor, and the increased width lowers the impedance. Effectively it is like connecting lots of infinitely thin 1/4 wave stubs to the same point, then fanning them out.
I *think* they are normally placed around 3/4 of a wave up the thin track, to put them at a high impedance point and increase their effect. Thats what I normally do with them anyway.
Robin Szemeti - G1YFG