Design of image-reject hairpin filter applied for Ku-band LNB

An image-reject hairpin bandpass filter used in Ku-band low noise block (LNB) is designed, and optimized in the paper. The designed detail of the filter is explained and the image-reject is illustrated theoretically. According to the research, under the condition of reducing the size as small as possible, the hairpin filter used in Ku-band LNB we designed not only can satisfy the demands from bandwidth and return loss, but also has good image-reject. In the end, the results of the simulation and measurement are presented, which prove the feasibility of our design.