The image parameter method of filter design involves the specification of passband and
stopband characteristics for a cascade of simple two-port networks, and so is related in concept
to the periodic structures of Section 8.1. The method is relatively simple but has the
disadvantage that an arbitrary frequency response cannot be incorporated into the design.
This is in contrast to the insertion loss method, which is the subject of the following section.
Nevertheless, the image parameter method is useful for simple filters, and it provides a link
between infinite periodic structures and practical filter design. The image parameter method
also finds application in solid-state traveling-wave amplifier design.