Question
Literature source [POZAR] available here:
https://www.amazon.co.uk/Microwave-Engineering-David-M-Pozar/dp/0470631554
There's also a solutions manual available here:
https://www.scribd.com/doc/176505749/Microwave-engineering-pozar-4th-Ed-solutions-manual
Answer
For Open Circuit and Short circuit lossy transmission line stubs there are peaks of valleys of reactance close to multiples of λ/4 and 3λ/4 (equivalent electric lengths π/2 and 3π/2).
Since there's always some real part of the input impedance, it's about choosing a length that supplies high enough |reactance| while keeping the resistive part low enough for the OC/SC stub to be considered an equivalent 'good' capacitor or inductor.
Attached MATLAB script that shows how to find such reactance peaks and valleys for a section of lossy transmission line.
Literature source [POZAR] available here:
https://www.amazon.co.uk/Microwave-Engineering-David-M-Pozar/dp/0470631554
There's also a solutions manual available here:
https://www.scribd.com/doc/176505749/Microwave-engineering-pozar-4th-Ed-solutions-manual
Answer
For Open Circuit and Short circuit lossy transmission line stubs there are peaks of valleys of reactance close to multiples of λ/4 and 3λ/4 (equivalent electric lengths π/2 and 3π/2).
Since there's always some real part of the input impedance, it's about choosing a length that supplies high enough |reactance| while keeping the resistive part low enough for the OC/SC stub to be considered an equivalent 'good' capacitor or inductor.
Attached MATLAB script that shows how to find such reactance peaks and valleys for a section of lossy transmission line.