RF and Microwave : Quarter Wave Line

[Girish Doherty Ajmera]

Using a Quarter Wave Line (Microstrip Line) we can realize an series or parallel combination of LC. but is it possible to get only inductance realization using quarter wave transmission line (Microstrip Line) by somehow controlling its width? thanks in advance

 

[reidintransit]

Depends on the bandwidth you need. You can design the microstrip to be inductive at quarter wave, but as you get higher in frequency the line will appear capacitive and even higher frequency will look inductive again. The smith chart is a valuable tool to understand this phenomenon visually.

 

[jiripolivka]

NO!!! The QUARTE-WAVE line section is equivalent to the PARALLEL resonant circuit! The HALF-WAVE section , to SERIES resonant circuit.

Any line length shorter than a quarter wave is inductive and can be tuned to resonance by a parallel capacitor. The width determines line characteristic impedance only.