Abstract:
During the evolution of integrated circuits, the noise content of silicon complementary
metal oxide semiconductor (CMOS) process was initially considered too
high, which made compound semiconductors preferable for achieving superior high
frequency characteristics. Nevertheless, rapid advancement and scaling down of
CMOS technology, having started with an original intention of improving digital
circuits, have allowed the development of cost-efficient monolithic silicon integrated
architectures for communication. An efficient way to reduce overhead of silicon
circuits further is to develop accurate models of its member elements. It can
significantly reduce the number of attempts (and hence cost) required to achieve
desirable performance from a prototype transceiver. This study presents a technique
to accurately estimate the behavior of nanoscale CMOS circuits with geometry
scalable discrete modeling. Rather than individual characterization of elements as
presented in literature, the scheme attempts to predict gain, noise, and reflectionloss
of integrated low-noise amplifier architectures. It reduces number of dissociated
parameters by formulating dependent functions through symmetric distributed
modeling. Geometry scalable empirical expressions based on physical structure and
describing parasitic components, which should lower the scheme's computational
complexity, are developed for elements like metal-insulator-metal (MIM) capacitor,
planar-spiral-symmetric (PSS) inductor, polysilicon (PS) resistor, and active device.
Results obtained with the models are compared against literature data of 1.2-V
amplifier circuits where high prediction accuracy is achieved for microwave
parameters (S21, NF, S11, S22). In the next phase, the study focuses on a lowpower
technique to improve performance reliability of CMOS amplifiers using a
integrated voltage network