A Low-Loss, Broadband, and Compact MMIC Packaging Solution for Sub-Terahertz Applications

This article presents a compact, broadband, and low-loss monolithic millimeter-wave integrated circuit (MMIC) packaging solution at sub-terahertz (sub-THz) frequencies. This design employs a patterned quartz substrate to realize mode conversion and interconnection between the waveguide and the chip, along with a Chebyshev transformer for wideband impedance matching. In order to prevent energy leakage, a sandwich-like glide-symmetric holey (SGSH) electromagnetic bandgap (EBG) structure is arranged around the waveguide, and a bed of nails is placed above the patterned quartz. To verify the proposed solution, a back-to-back (B2B) transition, a low-noise amplifier (LNA) module, and a frequency doubler module operating at the D-band (110-170 GHz) were designed, fabricated, and tested. The measured results exhibit good agreement with the simulated results. For the B2B transition, the measured return loss is better than 10 dB, and the de-embedded average loss is less than 0.5 dB across the entire D-band. The advantages demonstrate the potential of the proposed method for high-performance packaging in sub-THz applications.