Building Blocks for a Millimeter-Wave Multiport Multicast Chip-to-Chip Interconnect Based on Dielectric Waveguides

Abstract

A multichip multiport communication network technology is proposed based on a network of dielectric waveguides. For optimum performance and best versatility, a combination of high-permittivity dielectric slab waveguide and low-permittivity flexible dielectric rod waveguide is proposed. Additional building blocks are a dielectric waveguide Y junction and transitions between waveguide types as well as between chip and waveguide. The resulting multichip multicast multiport interconnect network features low overall transmission loss and small chip-area consumption for the chip-to-waveguide transitions. Measurement results for all components are presented for frequency bands around 60 GHz and around 100 GHz. The insertion loss of the transition from on-chip microstrip line to dielectric slab waveguide, extracted from end-to-end measurements, is 3.3 dB around 60 GHz and 2.2 dB around 100 GHz. Experimental four-terminal networks, each comprising four chip-to-waveguide transitions and two dielectric waveguide Y junctions, show measured end-to-end insertion loss (including pass through two Y junctions and two chip-to-waveguide transitions) of 21 dB (around 60 GHz, covering 26-mm distance) and of 17 dB (around 100 GHz, covering 20-mm distance), respectively. These values outperform wireless interconnects by far and emphasize the performance and versatility of the proposed approach for chip-to-chip multicast multiport interconnects.