A novel Ka-band folded dual-mode band-pass filter with LTCC technology

A Ka-band compact dual-mode band-pass filter is presented in this paper based on two square-loop dual-mode resonator using multilayer low-temperature co-fired ceramic (LTCC) technique. A new design about single dual-mode filter using LTCC technology is presented, which use coupling between layers technology instead of the parallel coupling technology, reflecting the integration advantages of LTCC technology. A four order square-loop dual-mode band-pass filter is folded by inserting a vertical via hole in the metal layer, which is used for the circuit size reduction with its area about a half of the conventional fourth order dual-mode plane microstrip band-pass filter. The simulation results show that insertion loss and return loss better than 0.5 dB and 16dB, in the pass-band of 33.634.7GHz.