A Band Stop to Band Pass Filter Transformation Utilizing 3-D Printing Technique for C-band Applications

In this paper, a band-pass filter (BPF) based on split-ring resonator (SRR) using a 3-D printing tech-nique for C-band applications is introduced. The pro-posed filter is designed to operate at a frequency of 3.9 GHz. An innovative technique for printing the sub-strate with a size of 24 x 24 x 1.1 mm3 using PLA di-electric material is implemented. The copper sheet with a thickness of 0.1 mm is printed on the upper and lower faces of the substrate. First, the SRR band stop filter (BSF) is introduced then two L-Stubs are inserted to im-plement an additional band stop region, and this rejoin is adjusted to obtain a band-pass region between the two stopbands. The BPF is operated at a 3-dB bandwidth ex-tended from 3.5 GHz to 4.3 GHz with an S21 level of -0.2 dB for the simulated results while it achieves a 3 -dB bandwidth within 3.6 GHz to 4.2 GHz (15.3 %) with an S21 level of -1.8 dB for the measured results.