Design methodology based on the inversion coefficient for RF and mmW circuits optimization using 28 nm FDSOI technology
RF design, inversion coefficient, FDSOI
The main idea of this work is to explore some advanced design methodologies taking advantage of the gm/Id and inversion coefficient based techniques using the FDSOI 28 nm technology. Those techniques have been extensively used for analog design since 1990. However, with the rising of new advanced technologies allowing higher Ft for transistors, many works exploiting those techniques have been dedicated to RF circuit design since 2010. For instance, many publications exploit the design methodologies for designing low noise amplifiers (LNA).
From the selection of the optimal inversion region for a given technology, we were progressively developing some methodologies that take into account the circuit topology and the set of specifications to choose the optimal inversion conditions.
Recently, there are few works analyzing precisely the linearity limitations and developing design methodologies for circuits such as Voltage controlled oscillators (VCO) or power amplifiers (PA). However, some recent articles have introduced through some compact models like ACM and EKV, a modelization of the non-linear effects in the transistors with short channel effects and express them as functions of the inversion coefficient.
The aim of this work is to take advantage of those models dealing with non-linear effects to develop design methodologies of non-linear circuits in particular VCO. Based on the gm/id and inversion coefficient methods and applied on advanced technologies such as FDSOI, those methods will give special attention to power efficiency.
Besides, in a context of 5G applications, mmW bands are essential to handle with the growing rates. Thus, an additional objectif is to extend the design methodology towards higher frequencies and determine their limitations especially when approaching frequencies in the order of Ft/fmax of the technology. In fact, the gm/Id methodology allow to design circits by maximizing the power efficiency which generally is correlated wit an increase in the transistor's widths. As a result, some parasitic effects rise and become more critical at high frequencies.
Mis à jour le 3 May 2022