SWR/Power meter
From Note to self
Links
- W2AEW Tutorial about directional couplers (Very very good)
- QEX Article about a SWR meter using AD8307 logamps
- Microstrip and Stripline Design Analog Devices Tutorial
- Directional Couplers / SWR detectors for 145MHz - 435MHz
- Multi-Teknik Impedance calculator
- How to measure transmission line impedance
- Introduction to transmission lines
- Smith chart tutorial
Step 1
The plan is to make a test setup, somewhat like what W2AEW did, but with an embedded microstrip design like in the QEX article. The idea is then to measure properties with my N2PK VNA. Or at least, try to.
Impedance
So, the big problem, how wide should the traces be. According to the calculator from Multi-Teknik, referencenced in the QEX calculator, I get a width that varies a bit around 2.1mm (trace thickness = 0.035mm, h=1.6mm, total height = 3.2mm, Er=4.2...4.8).