Millimeter-Wave LNA and PA MMICs With 10:1 and 4:1 Bandwidth in a 35-nm Gate-Length InGaAs mHEMT Technology

This paper presents two distributed amplifier monolithic microwave integrated circuits (MMICs) considerably exceeding an octave bandwidth at the upper millimeter-wave frequency range. The first MMIC is designed as a low-noise amplifier (LNA) with a dc-coupled transistor cell in a well-established small-signal-optimized traveling-wave-amplifier topology. The LNA achieves a decade bandwidth with an associated S21 of more than 19.8dB from 28 to 280GHz. The measured noise figure (NF) of the LNA is between 2.9–6.6dB (measured between 50–205GHz) with an average NF of 3.5dB between 75–150GHz. The second MMIC is optimized for highest output power (Pout) for a 4:1 bandwidth from 50 to 200GHz. The power amplifier (PA) is based on a gain cell with capacitive voltage division at the input of the cell. The measured Pout is better than 14.8dBm over the entire frequency range and achieves a maximum Pout of 19.5dBm at an operating frequency of 155GHz. To the best of the authors’ knowledge, both MMICs present state-of-the-art performance in their corresponding field of plus-octave bandwidth LNAs and PAs, respectively.