Weber, RainerRainerWeberWagner, SandrineSandrineWagnerLeuther, ArnulfArnulfLeutherTessmann, AxelAxelTessmann2024-08-132024-08-132024https://publica.fraunhofer.de/handle/publica/47313210.1109/IMS40175.2024.10600199A X4 frequency multiplier chip is presented in this paper. The MMIC was realized in a 35-nm mHEMT technology. It contains a chain of two differential frequency doublers followed by an amplifier. A vertically stacked Marchand balun provides the differential signal for each frequency doubler stage. Due to the use of folded thin film microstrip transmission lines (TF-MSL) and a folded Marchand balun a compact layout was possible. The MMIC achieves a maximum output power of 6.9 dBm and covers almost the whole F-band between 94 GHz and 140 GHz. This is a relative bandwidth of 39.3 %. The strongest unwanted harmonic is suppressed by more than 30 dBc starting from 98 GHz. Partly the suppression exceeds 40 dBc.enfrequency multiplierX4 multiplierquadruplermultiplier-by-fourspectral puritythin film microstrip transmission line (TF-MSL)F-Band (90-140 GHz)G-Band (110 to 170 GHz)metaphoric high electron mobility (mHEMT)monolithic millimeter-wave integrated circuit (MMIC)conference paper