How to Make an Open Microstrip Longer

Hi,

I need to make an open stub longer on a microstrip matching network made on Rogers R4000 laminate. Any ideas?

Just for testing? You could use conducting silver paint, or cut a a thin sheet of copper and solder it the your line. I often used the second method (copper sheet) for experimental tuning of microstrip circuits.

There are copper and silver tapes.

simple capacitive loading at the end will change is apparently length by 10-20%. You can do that with silver paint, a little dielectric slab at the end, tuning screw in close proximity, varactor diode, chip capacitor, etc.

If you need more than that, you will need to "add on" additional microstrip length via copper tape.

You can easily use copper tape.