Why would we prefer an active inductor over a passive inductor in RF integrated circuit design?

I personally prefer active inductors when I'm working on compact RF circuits. Passive spiral inductors take up a lot of chip area, and once you fabricate them, their inductance is fixed. That’s not ideal when you need flexibility during tuning or prototyping. Active inductors, on the other hand, are tunable — I can tweak the inductance just by changing bias currents. That alone saves a ton of design hassle.

With active inductors, you can change bias conditions to tune the inductance value. But in passive inductors, once you design and fabricate it, you can’t change it. That flexibility is a big advantage in RF design.

Active inductors are not always perfect, but we prefer them when high quality factor (Q) and integration with other circuits matter. Passive inductors on-chip usually have low Q due to substrate losses, while active ones can achieve higher Q for certain frequency ranges.