A millimeter-wave low-noise amplifier MMIC with integrated power detector and gain control functionality

A compact E-band amplifier circuit has been developed for use in ultra-high capacity point-to-point communication links. The millimeter-wave monolithic integrated circuit (MMIC) consists of a two-stage low-noise amplifier (LNA), a 10 dB line coupler, an integrated detector diode and a single-stage variable gain amplifier (VGA). The multifunctional MMIC was realized by using a 50 nm InAlAs/InGaAs based metamorphic high electron mobility transistor (mHEMT) technology in combination with grounded coplanar waveguide topology (GCPW) and cascode transistors, thus leading to a very low noise figure in combination with high gain and large operational bandwidth at millimeter-wave frequencies. The fabricated LNA circuit achieved a maximum gain of 37 dB at 78 GHz and more than 34 dB in the frequency range from 69 to 98 GHz. Furthermore, a room temperature (T = 293 K) noise figure of 2.3 dB and a detector responsivity of 39.000 V/W have been obtained at the frequency of operation.