Millimeter-wave power operation of an AlGaAs/InGaAs/GaAs quantum well MISFET

The authors have developed state-of-the-art millimeter-wave power transistors using quantum-well MISFETs. MISFETs with both undoped InGaAs wells and doped InGaAs wells have been built. The f/sub t/ of the MISFETs with doped well was higher than that of MISFETs with undoped wells, indicating that the device speed does not degrade when the charge transport layer is doped. The power performance of the MISFETs with doped wells was far superior. The best device delivered a power density of 1.0 W/mm with 3.2-dB gain and 27% power-added efficiency at 60 GHz.<
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