NOISE PARAMETER MODELING FOR INP-BASED PSEUDOMORPHIC HEMTS

The effect of electron mobility (mu(n)) on noise properties for InP-ba sed pseudomorphic HEMT's has been analyzed based on the impedance fiel d model, The analysis predicts that increasing mu(n) improves the mini mum noise figure (F-min) and associated gain not only because the unit y current gain cut-off frequency increases but also because the source resistance is reduced, The analysis also predicts that increasing mu( n) reduces the input noise resistance due to higher transconductance b ut hardly influences the noise-optimum impedance, Furthermore, it is p redicted that the decrease in F-min with increasing mu(n) becomes less significant above 11000 cm(2)/V s due to larger diffusion noise, Calc ulated results compare well with the measured scattering and noise par ameters for InxGa1-xAs (x = 0.53, 0.7, and 0.8) channel devices, Simil ar dependence of noise parameters on mu(n) is shown in the theoretical and experimental results.