"阶式滤波器" can be translated as "cascaded filter" or "stepped filter" in English, depending on the specific context and design characteristics of the filter.
Cascaded filter is a more common and general term, referring to a filter composed of multiple filter stages connected in series, where each stage processes the signal sequentially.
Stepped filter may be used in certain contexts to emphasize the step-like or staged nature of the filter's design or operation.
In most technical contexts, especially in electrical engineering and signal processing, "cascaded filter" would be the preferred and more widely recognized term.