In the past few years, a new type of circuit
board, named here as active substrate board (ASB), was introduced over circuit
applications of diodes. Unlike a traditional printed circuit board (PCB), an ASB
has its substrate made of a semiconductor. The inability of the traditional
integrated circuit (IC) technology to integrate wavelength dependent radio
frequency (RF) components triggered the advent of ASBs. These boards draw
desirable features from IC as well as PCB technologies. Unprecedented
challenges came up in modeling the different devices fabricated on an ASB owing to their large sizes and the presence of
wideband microwaves. So far, modeling the effect of large sizes and ambient microwaves
on DC bias of diodes have not been considered in scientific literature. Furthermore,
the state of the art numerical simulators are unable to imitate the behavior of
such diodes observed over measurements. Here, a semi-analytical, circuit model of
distributed diodes on ASB is presented that is fairly accurate in predicting
the actual behavior of the diodes. The model also opines a novel phenomenon where
microwaves affect the DC characteristics of diodes with added resistances.