CAD Modeling of mm-Wave Circuits Incorporating Avalanche Noise Diodes

In the present work a custom-developed, avalanche noise diode model is used in a commercial CAD software and is applied to three real case scenarios. Among the few noise diodes that have been characterized in recent years, and whose models are available in the literature, the 20 µm2 p-i-n diode developed with commercial a 130-nm SiGe BiCMOS technology is considered. Simulations are carried out with the diode connected to: (i) the attenuator of a noise injection circuit in a total power radiometer, (ii) the switching section of a Dicke radiometer, (iii) and a SIW band-pass filter for satellite receivers (emulating the frequency response of the front-end). The equivalent noise temperature at the output of all the above systems is evaluated according to the circuital blocks behavior, showing realistic responses of the diode in combination with passive devices. This paper shows that the presented avalanche noise diode model, previously not available in modern CAD, is applicable to other avalanche diodes available in literature and used to rigorously study passive systems.