Wide Bandwidth Millimeter Wave Mixer Using a Diffusion-Cooled Two-Dimensional Electron Gas
07 May 2001
Very fast millimeter wave mixers have been fabricated from a high mobility two-dimensional electron gas (2DEG) in a GaAs-AlGaAs heterostructure. Using a 115 GHz local oscillator, intermediate frequency (IF) bandwidths up to 36 GHz have been obtained for channel lengths L of a few microns. Operating at 77 K, the IF bandwidth scales as L sup (-2), indicating that the response speed is determined by the diffusion transit time of hot electrons to the leads. The bandwidth properties follow the principles of diffusion cooling in a 2DEG.