A notched UWB filter with LTCC technology

A notched ultra-wideband (UWB: 3.1GHz-10.6GHz) bandpass filter (BPF) using step impedance resonator (SIR) with LTCC technology and coplanar waveguide (CPW) was presented in this paper. And it with a controllable narrow notch (rejection) band with 1/2λ SIR structure. It was verified that the SIR was able to create a narrower notch band than other structures, such as spur-lines and open circuited. And in this paper some quarter-wavelength transmission lines were used to increase transmission zeros for good rejection performance. The results simulation of return loss is less than -14dB, the insertion loss is less than 0.5dB and the wide stopband after 20GHz with attenuation more than 12dB. The size of the UWB filter is 7mm × 8mm × 0.55mm.