Linearization of High frequency Class E Feedback Amplifier using Negative Impedance Method

Abstract

This work represents a novel method of linearization of Switch Mode Power Amplifier (SMPA). For this purpose, class E SMPA was designed and analyzed both before and after applying a linearization technique known as Negative Impedance method. One of the major characteristics of a standard SMPA is that they poses high efficiency than their linear counterpart but on the other hand they show highly nonlinear characteristics. The motivation behind this work is to harness this highly efficient amplifier and make it linear which can very useful for various applications in RF communication fields. All the schematics and simulations that are presented in this paper was performed using Cadence Virtuoso environment using “Spectre” simulator tool. For active components, 280nm process technology was used under “gpdk90” pdk which based on BSIM3v3 model. Circuit was designed to run at 2GHz with 2.5 V supply voltage. A mathematical model is also presented using data found from the analysis, with the help of MATLAB. Linearity was measured using Input referred Intercept Point of 3^rd order frequency (IIP3), which was improved from 3.7dBm to 17.86dBm with 57% percent efficiency providing an output power of 15.78dBm.