This article describes an 8x1 transmitter front end and an 8x1 receiver front end, each assembled from two in-parallel four-channel submillimeter-wave monolithic ICs (SMMICs). These SMMICs are manufactured in a 35 nm metamorphic high-electron-mobility transistor (HEMT) technology and integrate frequency multipliers, mixers, amplifiers and on-chip antennas. The broadside-radiating on-chip antennas simplify manufacturing with face-up assembly on a PCB. The frequency multiplier chain accepts a low frequency input drive from 22.5 to 26.25 GHz. Radiated output power of at least 10 mW is achieved for the frequency range from 390 to 420 GHz when all eight channels of the transmitter front-end are active, setting the state-of-the-art.