Advanced

Microwave CMOS Beamforming Transmitters

Wernehag, Johan LU (2008) In Department of Electrical and Information Technology, Series of licentiate and doctoral theses 12.
Abstract
The increase of the consumer electronics market the last couple of decades has been

one of the main drivers of IC process technology development. The majority of the

ICs are used in digital applications, and for these CMOS is the choice of technology.

The urge to squeeze more transistors on to a given area has led to shrinking feature

sizes. It has resulted in higher transition frequencies and reduced supply voltage.

During the last decade the increasing transition frequency has enabled CMOS to be

used in RF applications, as well. Unfortunately, the decreasing supply voltage that,

until recently, has accompanied the reduced feature sizes makes it more difficult to

... (More)
The increase of the consumer electronics market the last couple of decades has been

one of the main drivers of IC process technology development. The majority of the

ICs are used in digital applications, and for these CMOS is the choice of technology.

The urge to squeeze more transistors on to a given area has led to shrinking feature

sizes. It has resulted in higher transition frequencies and reduced supply voltage.

During the last decade the increasing transition frequency has enabled CMOS to be

used in RF applications, as well. Unfortunately, the decreasing supply voltage that,

until recently, has accompanied the reduced feature sizes makes it more difficult to

build power amplifiers that can deliver the amount of power needed to transmit the

radio signal over the desired distance. In the receiver, the reduced supply voltage has

resulted in reduced signal swing, which compromises linearity and dynamic range.

In this thesis new topologies for the power amplifier is investigated, and the approach

to combine the power from multiple power amplifiers is taken. In this way,

despite the low supply voltage, the transmitted power by the IC can still be high. The

increased transition frequency of CMOS technology can be used to increase the operating

frequency to tens of GHz. The possibility for small sized phased antenna arrays

then reveals, giving high directivity of the antenna and the potential for electrical beam

steering. This both reduces interference to nearby receivers through spatial selectivity,

and increases the equivalent isotropic radiated power. Power amplifiers with digital

360◦ phase control and antenna arrays have been investigated.

In recent years applications at high operating frequencies have attained much focus

from both academia and industry, such as automotive radar at 77 GHz andWLAN

at 60 GHz. Even though the shrinking feature sizes of CMOS transistors have resulted

in transit frequencies above 150 GHz, the high frequency required by many applications

is still a great challenge for the CMOS designer. Therefore, in Paper IV and

Paper VI different approaches to keep the on chip frequency lower than the RF carrier

frequency as long as possible have been taken. In Paper IV two different frequency

doubling 60 GHz power amplifier topologies are presented, and in Paper VI a subharmonic

mixer with 30 GHz radio frequency and 15 GHz differential local oscillator is

presented.

Many transceiver architectures rely on quadrature signals driving the down- or upconversion

mixers. The power amplifiers in Paper I and II need quadrature signals

to implement the digital phase control. Therefore, in Paper V a three-stage active

polyphase filter with quadrature output signals, high operation frequency, and wide

bandwidth is analyzed. Analytical equations for both voltage gain and phase transfer

function of a loaded stage are derived. The filter shows robustness against process

parameter spread and achieves high quadrature signal quality from 6 GHz to 14 GHz. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Associate Professor Klumperink, Eric, University of Twente, Department of Electrical Engineering
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Beamforming transmitter, CMOS, frequency doubling power amplifier, polyphase filter, phase shifting
in
Department of Electrical and Information Technology, Series of licentiate and doctoral theses
volume
12
pages
234 pages
publisher
Tryckeriet i E-huset, Lunds universitet
defense location
Lecture Hall E:1406, E-building, John Ericssons väg 4, Lund University, Faculty of Engineering, LTH
defense date
2008-12-12 10:15
ISSN
1654-790X
language
English
LU publication?
yes
id
2122dca9-b20e-4f1b-8819-e7ffb39bebf6 (old id 1265511)
date added to LUP
2008-11-17 13:15:30
date last changed
2016-09-19 08:44:49
@phdthesis{2122dca9-b20e-4f1b-8819-e7ffb39bebf6,
  abstract     = {The increase of the consumer electronics market the last couple of decades has been<br/><br>
one of the main drivers of IC process technology development. The majority of the<br/><br>
ICs are used in digital applications, and for these CMOS is the choice of technology.<br/><br>
The urge to squeeze more transistors on to a given area has led to shrinking feature<br/><br>
sizes. It has resulted in higher transition frequencies and reduced supply voltage.<br/><br>
During the last decade the increasing transition frequency has enabled CMOS to be<br/><br>
used in RF applications, as well. Unfortunately, the decreasing supply voltage that,<br/><br>
until recently, has accompanied the reduced feature sizes makes it more difficult to<br/><br>
build power amplifiers that can deliver the amount of power needed to transmit the<br/><br>
radio signal over the desired distance. In the receiver, the reduced supply voltage has<br/><br>
resulted in reduced signal swing, which compromises linearity and dynamic range.<br/><br>
In this thesis new topologies for the power amplifier is investigated, and the approach<br/><br>
to combine the power from multiple power amplifiers is taken. In this way,<br/><br>
despite the low supply voltage, the transmitted power by the IC can still be high. The<br/><br>
increased transition frequency of CMOS technology can be used to increase the operating<br/><br>
frequency to tens of GHz. The possibility for small sized phased antenna arrays<br/><br>
then reveals, giving high directivity of the antenna and the potential for electrical beam<br/><br>
steering. This both reduces interference to nearby receivers through spatial selectivity,<br/><br>
and increases the equivalent isotropic radiated power. Power amplifiers with digital<br/><br>
360◦ phase control and antenna arrays have been investigated.<br/><br>
In recent years applications at high operating frequencies have attained much focus<br/><br>
from both academia and industry, such as automotive radar at 77 GHz andWLAN<br/><br>
at 60 GHz. Even though the shrinking feature sizes of CMOS transistors have resulted<br/><br>
in transit frequencies above 150 GHz, the high frequency required by many applications<br/><br>
is still a great challenge for the CMOS designer. Therefore, in Paper IV and<br/><br>
Paper VI different approaches to keep the on chip frequency lower than the RF carrier<br/><br>
frequency as long as possible have been taken. In Paper IV two different frequency<br/><br>
doubling 60 GHz power amplifier topologies are presented, and in Paper VI a subharmonic<br/><br>
mixer with 30 GHz radio frequency and 15 GHz differential local oscillator is<br/><br>
presented.<br/><br>
Many transceiver architectures rely on quadrature signals driving the down- or upconversion<br/><br>
mixers. The power amplifiers in Paper I and II need quadrature signals<br/><br>
to implement the digital phase control. Therefore, in Paper V a three-stage active<br/><br>
polyphase filter with quadrature output signals, high operation frequency, and wide<br/><br>
bandwidth is analyzed. Analytical equations for both voltage gain and phase transfer<br/><br>
function of a loaded stage are derived. The filter shows robustness against process<br/><br>
parameter spread and achieves high quadrature signal quality from 6 GHz to 14 GHz.},
  author       = {Wernehag, Johan},
  issn         = {1654-790X},
  keyword      = {Beamforming transmitter,CMOS,frequency doubling power amplifier,polyphase filter,phase shifting},
  language     = {eng},
  pages        = {234},
  publisher    = {Tryckeriet i E-huset, Lunds universitet},
  school       = {Lund University},
  series       = {Department of Electrical and Information Technology, Series of licentiate and doctoral theses},
  title        = {Microwave CMOS Beamforming Transmitters},
  volume       = {12},
  year         = {2008},
}