In this paper, the design and simulation of a symmetrical waveguide filter are presented based on insertion loss method. The designed WR-34 is operating at 28 GHz, where its dimensions a=4.32mm b=8.64mm, fractional bandwidth 2.15% return level better than 16 dB, frequency range from 22Ghz to 33 GHz. structure 5 th -order bandpass with five resonators six circular inductive irises. order optimiz...