Novel bandpass filter using couplers and resistors for millimeter-wave MMIC application

A new passive bandpass filter with a planar structure using directional couplers and resistors is proposed. The characteristics of the filter are examined up to the millimeterwave frequency band. The parameter dependence of the filter is calculated and it is found that this new filter has a potential to obtain lower insertion loss and higher selectivity characteristics than conventional filters. It can also provide a high return loss in a wide frequency band range. This new filter is practical for application to mm-wave MMICs.