A sixth order Ka band filter is presented based on the method of space mapping of single port group delay simulation. The filter is fabricated on aluminum oxide ceramic substrate, and the chip size occupies 8 mm×2.5 mm×0.254 mm. The measurement results show that the center frequency of Ka-band filter is located at 30.68 GHz with 3-dB Fractional BandWidth(FBW) of 11.5%, and the minimum insertion loss within the passband is about 1.75 dB.