Advanced multilayer thick‐film technology and TFMS, CPW, and SIW up to 180 GHz for cost‐effective ceramic‐based circuits and modules

Abstract

This study presents the design, accurate characterisation, and performance comparison for multilayer thin-film microstrip (TFMS), coplanar waveguide (CPW), and substrate integrated waveguides (SIW) lines and interconnects for various transverse dimensions, which are fabricated on thin dielectric layers, using advanced ceramic-based photoimageable thick-film technology. The influence of ground-plane width on multilayer finite-ground planar transmission lines (TFMS and CPW) and the influence of cavity dimensions on SIW have been experimentally studied. This includes the variation of characteristic impedance and attenuation with normalised ground-/cavity-width and extending frequency to beyond 110 GHz (180 GHz, for SIW). Contrary to conventional fence-post, metal-filled trenches have been used for SIW, showing high performance (loss of 0.2 dB/mm at 110 GHz, even for a thin dielectric) and suitable for operation beyond 180 GHz, the highest frequency reported for off-chip integration in MCMs. Further, for the first time, comprehensive comparative performances of traditional microstrip, TFMS, CPW, and SIW, in circuit/system design perspective, have been presented for enabling proper selection of transmission media and interconnect with optimum transverse/ground width, and development of compact and high performance millimetre-wave multichip module front-ends economically.