New resonator arrangement for reduced size E-plane filters

A new all-metal insert E-plane filter consisting of single, upper and lower ridge resonators placed alternatively along the waveguide housing is introduced. The proposed topology allows one, in large extent, to adjust the filter length, which can be particularly useful when designing manifold type diplexers of extracted pole variety. The concept has been validated by designing and manufacturing of a 6-pole filter with transmission zero placed on the upper side of the pass-band.