Ultra-wide Bandwidth Inter-Chip Interconnects for Heterogeneous Millimeter-Wave and THz Circuits

Abstract

Heterogeneous chip-to-chip interconnects with low loss and ultra-wide bandwidths have been demonstrated. Coplanar waveguide-based interconnects between GaAs and Si die have been fabricated and characterized and the results compared to expectations from fullwave electromagnetic simulation. Broadband transmission characteristics were obtained, with insertion losses below 0.3 dB at 100 GHz and below 0.8 dB at frequencies up to 220 GHz demonstrated experimentally. The measured return loss exceeded 11.5 dB at all frequencies up to 220 GHz. The interconnects offer low latency, with a measured group delay of 0.69 ps. The measured results are in good agreement with full-wave simulations, indicating that the measured results do not suffer from significant impairments compared to theoretical predictions. The demonstrated interconnects offer an alternative to conventional approaches to millimeter-wave circuit and system integration, by enabling the compact realization of circuits in the microwave, millimeter-wave, sub-millimeter-wave, and THz frequency regimes in heterogeneous device technologies with very low chip-to-chip insertion loss.

Proposal and simulation of a DC–110 GHz waveguide using metal shielding and three-dimensional extension structure

“…To satisfy the needs of a terabyte data transmission rate, the high-speed electrical interconnect technique is the key to improving the performance of electronic systems. [1][2][3][4] Conventional interconnects such as the microstrip line and stripline have the increasingly prominent problems of signal integrity in the process of high-speed data transmission. [5][6][7][8][9] This open/semi-open circuit structure encounters serious problems of radiation and electromagnetic interference, resulting in large losses at high frequencies and a limiting transmission band in low-frequencies.…”