Self-equalised pseudo-elliptical filter made of substrate integrated waveguide

A self-equalised pseudo-elliptical filter on the basis of substrate integrated waveguide technology is proposed and demonstrated over the Ka-band range. The extracted-pole technique is used to synthesise a sixth-order filter with non-resonating nodes. Measured results of the filter exhibit a high selectivity and a minimum inband insertion loss of about 2.0 dB and small inband group delay variation.