Low cost SIW Chebyshev bandpass filter with new input/output connection

This paper presents a substrate integrated waveguide (SIW) Chebyshev bandpass filter using the low cost, commercially available printed circuit board (PCB) technology. The detailed design procedure beginning from the normalized Chebyshev lowpass filter, to the final optimized SIW bandpass filter is presented. The test filter having a 4% fractional bandwidth centered at 1.684 GHz was fabricated on a 1.27 mm thick, Rogers RT/Duroid 6010LM substrate with a 10.8 dielectric constant. The design has also been experimentally validated and results presented. The simulation and measurement responses of the filter show good agreement with a low insertion loss of 1.3 dB. The simulated and the measured return losses of about 15 dB and 16 dB respectively, were achieved across the filter passband.