Measurement-based analysis of GaAs HEMT technologies: Multilayer D-H pseudomorphic HEMT versus conventional S-H HEMT

The key objective of this study is to check out the performance of two multilayer processed double-heterojunction pHEMTs with different gate width as well as one conventional single-heterojunction HEMT. Different types of investigation have been undertaken by means of on-wafer DC, small-signal, and nonlinear two-tone measurements. The modeling of the DC output characteristics was successfully accomplished using the FET's Curtice model for all of three tested devices. The main figures of merit for microwave and millimeter wave applications have been determined from scattering parameter measurements and then discussed in detail. Furthermore, to attain a better insight of the device behavior, the nonlinear intermodulation distortion behavior has been also studied and compared for the three devices over different bias conditions. A careful analysis of the DC and RF characteristics over a wide range of working conditions is necessary to ensure adequate transistor operation, depending on the given application of interest.