Substrate Integration of Dual Inductive Post Waveguide Filter

Integration of planar circuits to non-planar ones has been recently considered as a credible technique for low-cost mass production of microwave and millimeter-wave circuits and systems. This paper regards these concepts that provide for a complete integration of planar circuits and waveguide filters synthesized on a single substrate by means of metalized post (via-hole) arrays. A method of designing a waveguide filter derived from a synthesis technique using dual array of inductive posts is presented. An experimental five-pole Chebyshev filter which has 2.5 dB insertion loss and return loss better than 10 dB is demonstrated. Such a technique of integration of planar and non-planar circuits on the same substrate shows a significant reduction in size, weight and cost.