A compact bandpass filter with SIW triangular cavities

In this paper, a compact bandpass cross-coupled substrate integrated waveguide (SIW) filter with transmission zero is proposed. Using three triangular cavities as basic elements, a bandpass filter is designed and fabricated on a single-layer substrate with the standard printed circuit boards (PCB) process. This structure gives full expression to the advantages of compact SIW triangular cavity. Not only the compact structure, but also the inverse feedback is the characteristic of the bandpass filter. The cross-coupled technique makes a sharper transition performance at the upper sideband and a great promotion to out-band.