Ultralow-noise pin-HEMT optical front end with spice noise modelling

Accurate modelling of HEMT noise mechanisms has been obtained using a new technique for implementing generalised noise sources in SPICE, including frequency and correlation effects. A pin-HEMT optical front end operating between 2.2 and 4.3GHz was designed, and the equivalent input noise spectral density was measured to be below 3.0pA/□(Hz) over the passband.