The invention discloses an ultra-
wideband (UWB) filter with band-notched characteristics. The UWB filter comprises a
metal microstrip line at a front face part, a
metal coating at a rear face part and a
dielectric slab at a middle layer, wherein, the
metal microstrip line is of a linear cascaded
microstrip line structure which is formed by alternately connecting comb coupled microstrip lines with a quarter of
wavelength and a microstrip line with half
wavelength; the microstrip line with half
wavelength is provided with microstrip slits; uniform transmission parts on the outer ends of the two comb coupled microstrip lines are respectively and electrically connected with input and output interfaces and two short-circuit stubs with a quarter of wavelength; and free ends of the short-circuit stubs with a quarter of wavelength are electrically connected with the
metal coating at the rear face part. The UWB filter disclosed by the invention has the advantages of good band-notched characteristics, high
coupling coefficient, small volume, easy
machining process, steep
sideband characteristics and good
frequency selectivity, and a
passband is internally provided with a steep trap with the relative width of more than 125%, thus meeting the requirement for
miniaturization.