A new class of Multi-band filters based on the same phase extension scheme

This paper presents a new class of Multi-band filters based on same phase extension scheme, in which each channel is dedicated to selected band and center frequency by using the scheme of same phase extension. The equivalent circuit is the combination of multi-inline networks connected with two manifold waveguides, the structure of which has the same phase extension. The advantage of this method is that each in line network represents an individual channel. A dual-mode tri-band filter is measured and described.