Design of a CMOS power amplifier and built-in sensors for variability monitoring and compensation

111 Pages·2017·1.92 MB·English

Design of a CMOS power amplifier and
built-in sensors for variability monitoring and
compensation
Dissertation presented to apply for
MSc Electronic Engineering
Alejandro Ferna´ndez Toma´s
Supervisors
Dr. Xavier Aragones Cervera
Dr. Josep Altet Sanahujes
October 2017

Design of a CMOS power amplifier and built-in
sensors for variability monitoring and compensation
Alejandro Fern´andez Tom´as
Supervisors
Dr. Xavier Aragones Cervera
Dr. Josep Altet Sanahujes
Full report of Alejandro Fern´andez Tom´as’s MSc thesis
to apply for the MSc Electronic Engineering
2016–2017
Electronic Engineering Department (DEE)
Universitat Polit`ecnica de Catalunya (UPC)

i
I think that when we know that we actually do live in
uncertainty, then we ought to admit it; it is of great value to
realize that we do not know the answers to different
questions. This attitude of mind - this attitude of uncertainty
- is vital to the scientist, and it is this attitude of mind which
the student must first acquire.
Richard P. Feynman

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ACKNOWLEDGMENTS
I would like to thank my family and Laura, for being always by my
side and for their endless patience.
To my colleagues Luis, Clever, David and Alex with whom I have
shared a lot of moments since we started our studies.
To my friends of Premia de Mar, for helping me to disconnect from
everything. Although we don’t get together as much as we want.
To professors Xavier Aragones, Josep Altet and Diego Mateo for
teachingmeeverythingIneededwithoutaskinganythinginreturn. From
them I have learned a working methodology that I will never forget.
To Quique, for helping me to carry out this work.

Summary
This research thesis aims to develop a system composed by a a CMOS power
amplifier and built-in sensors for variability monitoring and compensation.
The integration of monitoring systems with high frequency analog circuits is
commonly used for performance optimization and control. In addition, built-in
sensors are used in quality testing, improving the yield by detecting circuit
faults during the fabrication of these.
Typically, most of the built-in sensors are electrically connected to a node
of the circuit under test, affecting its performance. In tuned power amplifiers,
for instance, a small load variation can cause a degradation of its output power
and efficiency. Hence, the integration between the circuit under test and the
monitoring block should be carefully designed. These loading effects can be
avoided using non-invasive solutions such as temperature sensors.
An integrated circuit composed by a CMOS power amplifier, two amplitude
detectorsandatemperaturesensorisimplementedinthiswork. Thedegradation
of the power amplifier performance due to variability effects is accelerated by
increasingitssupplyvoltage. Afeedbackloopisaddedtocontrolandadjustthe
system operation, stress the amplifier and accelerate its degradation, monitor
the amplifier performance using the sensors and compensate the observed
degradation.
The design of each one of the main parts of the system is presented through
this work, explaining their theoretical basis and validating their operation with
simulationsresults. Finally,allthepartsareintegratedtogether,andafeedback
loop with a control algorithm is proposed to monitor and compensate the DUT
variability effects.
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