0.5-20GHz Driver GaAs Monolithic Microwave IC. The CHA4220-98F is a distributed driver amplifier which operates between 0.5 and 20GHz. It is designed for a wide range of applications such as military, telecom, test instrumentation. The circuit is manufactured with a pHEMT process, 0.25um gate length, via holes through the substrate, air bridges and electron beam gate lithography. It is supplied as bare die part with RF accesses matched on 50 ohms.