A Novel Miniature Transmit Reject Filter for Ku-Band VSAT Transceivers

In this paper, a novel miniature waveguide low-pass transmit reject filter (TRF) with a sharp cutoff frequency response is proposed for Ku-band VSAT (very small aperture terminal) transceiver. By introducing parallel resonators in a rectangular waveguide using short-circuited stubs, a compact low-pass filter with a very sharp out-of-band rejection is realized. An eleven-element Ku-band low-pass filter is designed and fabricated using a WR-75 waveguide. The measurement results show it has a low insertion loss of less than 0.3 dB at the pass band and a high attenuation slope of 70 dB/GHz. Moreover, the miniature size of the filter is only 38 mm times 38 mm times 42 mm (WR-75 flange size is 38 mm times 38 mm).