Abstract: In this paper,a method of designing and implementing a ultra-wideband LTCC bandpass filter is proposed. By loading capacitor between the two E-shaped resonator,the coupling between them is greatly enhanced,thus,the characteristic of ultra-wideband is realized. At the same,C-shaped defected ground structure is adopted to suppress the harmonic passband of the filter,improved the out-of-band performance of the proposed filter. A ultra-wideband filter is finally designed at 6. 75 GHz with bandwidth of 6. 5GHz,which the relative band-width reaches 96%. The proposed filter is fabricated with LTCC technology,the insertion loss is lower than 1d B,the return loss is better than-15 d B and the size of the filter is only 3mm × 4mm × 0. 5mm.