A single lambda/4 transmission line is called narrow band because if applied correctly it inverts impedance between ports, with reasonably large enough |s11|, but |s11| quickly rises on both sides of the single frequency chosen to calculate the characteristic impedance.
lambda/4 transmission line sections are also called transmission line impedance transformers. Example
What one can do is for instance combine more than one transmission line sections, for instance shut-series, like this:
Shut-series-shunt:
or cascaded sections, called binomial or Chebyshev impedance transformers according to what function used, example binomial 4 lambda/4 sections:
I don’t know if it’s your case for this question, but instead, it’s important to consider programming a DSP for instance, to do such impedance transforming / impedance matching / filtering, saving considerable PCB space. After all, smart phones do a lot of RF/microwave signal processing with just a few, as small as possible, components, as National Instruments motto used to read some years ago: Software is the Instrument.