Single-Stub Impedance Matching

Hi,

I'm little confused with the stub position in stub tuning process. Let's say we have been given to match a load using single-stub whether short or open. I did both as an exercise and where I got myself stuck was the position of the stub. The query is: whatever the stub is? whether short or open, the stub position is not going to change; only length vary while switching from short to open or open to short stub.

Thanks in anticipation!

Funny question, a had never really thought of that.
But yes, you're right, the only parameter that counts is the length of the stub, regardless of its own load (0 or inf).
The distance from the stub to the load depends only of the circuit load itself.

Hi,

You should use the shorter stub length of the two possibilities although they seem to be equivalent.

For an example, if short stub gives the required matching impedance, theoretically, you can add quarterwave length to the line and leave it open, it will be the same but only on one frequency. In other words, the bandwidth of this open stub matching will be narrower compared to the shorted stub.

flyhigh