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 the
Negative Impedance method. One of the major characteristics of
a standard SMPA is that they have higher 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 be very useful for various applications in RF communication
fields. All the schematics and simulations that are presented in
this paper were performed using the Cadence Virtuoso
environment using the “Spectre” simulator tool. For active
components, 280nm process technology was used under
“gpdk90” pdk which is based on BSIM3v3 model. The gpdk90
package includes devices ranging from 100nm to 280nm
processes for different voltage levels. The 280nm process was
chosen as it supports a maximum of 2.5V of supply. The 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 3rd order frequency
(IIP3), which was improved from 3.7dBm to 17.86dBm with 57%
percent efficiency providing an output power of 15.78dBm.