what are tuning dots and how to effectively use them

Question

I've come across some template designs that have tuning dots included for RF matching. Unfortunately they are using a different dielectric than I am.

What are the basic principles of tuning dots (theoretical to purely mathematical would be great), and how do I then change their design to fit my own boards specifications?

NOTE- tuning dots are filled in the end design, this is merely how my importer displays them

tuning dots in all their glory blurry=better picture of the tuning dots

what are the dimensions of the tuning pads and gaps between them? — DakotaD, Jun 16 '15 at 11:32

DakotaD · Accepted Answer · 2016-11-22T17:17:39.797

5

Their purpose is to provide a means of adding variable length stubs for impedance matching. A wire bond can be connected from the bondable gold surface of the microstrip center trace to the pad. The bond wire will have an inductance value based upon bond height/length and wire thickness; the bond pad will have a known capacitance based upon the substrate dielectric and the pad geometry.

A very brief mention of their use can be found here. Additionally, their use is discussed at Microwaves101, where they are called "chicken dots".

edited Nov 22 '16 at 17:17

answered Jun 16 '15 at 17:33

DakotaD

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@LegenDiary fixed bad link – DakotaD Jun 16 '15 at 18:02
I upvoted the answer. I'm checking with the original designer. If it's the same answer I'll accept it as correct. – Legen Diary Jun 16 '15 at 18:25
no response. What you've said makes sense – Legen Diary Jun 26 '15 at 17:13

what are tuning dots and how to effectively use them

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