Terminator3
Advanced Member level 3
In filters / matching schematic.
For example, if we do not want to add DC block capacitor on drain of transistor, we can use open-circuited matching stub. Also sometimes single-stub matching can be more compact with open-circuited stub and additional phasing line for rotating on Smith Chart.
There is my old question here:
https://www.edaboard.com/threads/294441/
But open-circuited subs are widely used. Is it because of VIA impedance difficulties at higher frequencies?
IMHO, most high frequency (>=10GHz) transistor matching is done using open-circuited stubs.
Also, microstrip band-pass filters are mostly built using half-wave resonators, and not interdigital quarterwave short-circuited "fingers" resonators. So i think that open-circuited stubs are somehow preferred nowdays.
For example, if we do not want to add DC block capacitor on drain of transistor, we can use open-circuited matching stub. Also sometimes single-stub matching can be more compact with open-circuited stub and additional phasing line for rotating on Smith Chart.
There is my old question here:
https://www.edaboard.com/threads/294441/
But open-circuited subs are widely used. Is it because of VIA impedance difficulties at higher frequencies?
IMHO, most high frequency (>=10GHz) transistor matching is done using open-circuited stubs.
Also, microstrip band-pass filters are mostly built using half-wave resonators, and not interdigital quarterwave short-circuited "fingers" resonators. So i think that open-circuited stubs are somehow preferred nowdays.
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