Broadband flip‐suspended‐microstrip transition for millimeter‐wave MMIC package

Abstract

AbstractIn this letter, a novel millimeter‐wave chip packaging method based on flip‐suspended‐microstrip technology is proposed. The flip‐suspended‐microstrip contains a waveguide probe, a suspended microstrip line, input and output matching lines, and a terminal pad. The waveguide probe realizes energy coupling from the rectangular waveguide, and the terminal pad above the signal pad of chip achieves power transmission via electronic contact. Thus, the bonding wires which will bring parasitic inductance at high frequencies are avoided. To validate the proposed packaging method, back‐to‐back modules with coplanar waveguide/low noise amplifier were fabricated. The measured insertion loss of the back‐to‐back transition with a 1.75‐mm‐long coplanar waveguide is 2.6–4.2 dB over the entire D‐band, while the packaging loss of the low noise amplifier module with the back‐to‐back transition is less than 2.2 dB at 120–170 GHz, which indicate that the proposed broadband transition is feasible for millimeter‐wave chip packaging.