The CHM1291 is a multifunction chip (MFC) which integrates a LO buffer amplifier and a subharmonically balanced diodes mixer for 2LO suppression and image rejection. It is usable both for up-conversion and down-conversion. It is designed for a wide range of applications, typically commercial communication systems for broadband local access (LMDS). The backside of the chip is both RF and DC grounded. This helps simplify the assembly process. The circuit is manufactured with a PM-HEMT process, 0.25m gate length, via holes through the substrate, air bridges and electron beam gate lithography.