A LOW PHASE-ERROR 44-GHZ HEMT ATTENUATOR

Radio frequency (RF) subsystems for emerging millimeter-wave applicati ons require monolithic microwave integrated circuit (MMIC) attenuators with constant phase over the attenuation range. In this letter, we pr esent the results for a 44-GHz stepped attenuator implemented in high electron mobility transistor (HEMT) MMIC technology. Use of a switched -path topology provides a high attenuation range (>30 dB) with good ph ase flatness (<7 degrees p-p) and return loss (>14.5 dB) over the atte nuation range. The same design topology should be well suited for othe r frequencies throughout the upper microwave and lower millimeter-wave range.