A Compact and Low-Cost THz SoP Heterogeneous Integration Platform

A compact and low-cost THz system-on-package (SoP) heterogeneous integration platform is proposed in this work. Different chips fabricated in different technologies can be integrated together onto a common low-loss and low-cost integrated-passive-devices (IPD) carrier using low-loss chip-to-IPD THz interconnects. On-carrier low-loss microstrip lines, coplanar waveguides, and substrate-integrated waveguides (SIW) are used to communicate signals between these different chip modules. Low-loss SIW filters on the IPD carrier are employed to filter out undesired spurs, harmonics, noise, and interference signals. Experimental results show that the proposed single-band, dual-band, and broadband THz interconnects from a 0.18-$\mu$ m CMOS chip to an IPD carrier can give insertion loss of 2, 2.8 and 3.2 dB, and lower than 3.7 dB at 306.5, 140 and 324.5 GHz, and from 140 to 330 GHz, while keeping the return loss better than 10 dB from 256.5 to 330, 140 to 182 and 280 to 330, and 140 to 330 GHz, respectively. The measured insertion loss of a fourth-order Chebyshev SIW filter realized in a commercially-available GaAs IPD technology is 3.6 dB at 327.5 GHz. With the proposed THz heterogeneous integration platform, the unique advantages of these different chip modules realized in different technologies can be utilized to carry out compact, high-performance, low-cost, and high-integration THz systems for sensing and communication applications.