In this paper, a simple dimensional design procedure is developed for microstrip/stripline quadruplet filters by starting with direct BP synthesis of a lumped quadruplet with inverter couplings, K14, K12, K23 and K34. K14 is the cross-coupling inverter which creates a symmetric pair of finite transmission zeros (FTZ's) if the sign of K14 is opposite of the other inverters while a complex TZ is created if K14 has the same sign as the other inverters leading to linear phase (flat delay) responses. The LC resonators are first converted into half wavelength transmission line (TL) resonators coupled by inverters. Then inverter coupled TL resonators are converted into parallel coupled lines (PCL) to form a PCL quadruplet. Two examples are presented, one with two symmetric FTZ's and one linear phase response.