A novel LTCC multilayer SIW linear phase filter

In this article, a novel multilayer substrate‐integrated waveguide (SIW) linear phase filter is proposed. Four SIW cavities are placed in two layers based on a standard low temperature cofired ceramic technology. Neural network is used to improve the efficiency of design. One slot which is etched on the top metal layer of SIW cavity is adopted to suppress the first high mode. Flat group delay characteristics can be achieved in the filter that has a rejection level of −25 dB in upper stopband. The filter has a 55% area reduction in comparison with planar structure. Good agreement is acquired between measured and simulated results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2357–2360, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24595