الفهرس Only 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
The growing size and tough requirements on RF systems besides challengeing time to market drive the need to accurate and fast system level simulation. Fast system level simulations can be achieved using behavioral models of system building blocks. These behavioral models must fully encompass block characteristics including gain and linearity. In our work we addressed nonlinearity behavioral modeling by performing nonlinearity anslysis to a CMOS Low Noise Amplifier ciecuit as a one of the main RF receiver building blocks. Our nonlinearity analysis technique is based on the symbolic calculation of nonlinear responses of LNA by adopting the Direct methid as a variant of Volterra series approach. Direct method depends on representing each nonlinearity element in the MOSFET transistor equivalent circuit as a power series expansion around its quiescent point. This representation necessitates the use of accurate MOSFET models that accurately describes the physical behavior in order to obtain accuracederivatives for the needed power series expansion. We used a relatively accurace physical MOSFET model in order to perform nonlinearity calculations. Our procedure resulted in a set of symbolic expression for nonlinear response up to order three at harmonic and intermodulation frequencies for a two tone input excitations. These symbolic expressions are very large and complicated; however, we demonstrated that they have small number of diminant contributors’ which give us the required insight to the nonlinearity behavior besides enabling us to describe the circuit in a more compact from using these dominant contributions.