Flip-Chip W-Band Amplifier: a Prototype of Q-MMICs

A prototype W-Band, low-noise amplifier has been fabricated by bump-bonding a high-speed, low-noise InP high-electron-mobility (HEMT) transistor onto the previously fabricated passive portion of the amplifier circuit on a GaAs substrate (see figure). The passive portion of the circuit can be regarded as a monolithic microwave integrated circuit (MMIC) that differs from a complete MMIC amplifier only in its lack of a single active device (the HEMT). Therefore, the bump-bonded combination of the active device and the passive portion of the circuit is characterized as a quasi-monolithic millimeter-wave integrated circuit (Q-MMIC).