Use of Multilayered-PCB for Q-band Substrate Integrated Waveguide Components

This paper proposes the design of a fourth order filter centered at 36 GHz. The particular technological process in use during this work allowed the realization of both blind and open-ended via-holes. Those were obtained by microvias or Plated Through Holes (PTH) techniques respectively. Originality of this work relies in the exploitation of this particular fabrication process to implement a filter using novel input/output couplings made from plungers. These couplings also assure the role of mode transition between the quasi-TEM microstrip mode to the Substrate Integrated Waveguide mode. Based on that technology and this novel coupling/transition, a prototype has been designed, simulated and fabricated on a 1mm-thick PCB made of copper and Megtron6 material (eps=3.6, tan(δ)=6e-3). Regarding the results of this device, measured insertion & return losses are in a very good agreement with simulations, and measured performances are Insertion Losses of 3 dB for an 8% relative bandpass filter centered at 36 GHz.