Cascade Connection

• An order can be increased by using a filter cascade.
• Each time the previous output $y$ is input to the filter, a new impulse response representing is created.

  Figure 9: A cascade of simple low-pass filters.

  
• The new output always has a finite number of non-zero components and a finite impulse response.
• For each first-order filter in the cascade, the impulse response increases by one.