Integrated Power Converters for high efficiency RF Systems

1

Integrated Power Converters for high
efficiency RF Systems


By:

Aaron Pereira


Supervisor:

Prof. Graham Town & Prof Neil Weste


Department of Electronic Engineering

Macquarie University, NSW, Australia.



2

Outline


•
Introduction

•
Background

•
Solution

•
Gallium Nitride Material & Devices

•
PA + High Efficiency Modulator

•
Triquint 0.25u process & circuits designed

•
Further Work

•
Questions


3

Introduction

MQ University Department of Electronics:

ARC Linkage Grant





•
Integrated

Power

converters

for

renewable

energy

systems


•
100
MHz

Envelope

tracking

system

using

GaN

process

for

base

station

applications


•
Using

Triquint

existing

0
.
25
u

GaN

process,

to

design

a

high

frequency,

high

efficiency

modulator

to

be

integrated

into

a

Power

Amplifier

(HEPA)

module

for

base

stations

applications
.

4

Background

RF Power Efficiency

5

Quest for Power, Linearity & Efficiency

VDD
RL
Bias
Vout
Rs
Vs
Source
Input
Network
Output
Network
RF
-
in
Power
Amplifier
Antenna
RF
-
out
Q

I

Edge Constellation:

3pi/8, rotated 8
-
PSK

Schematic of PA

Actual Size

Stauth, Sanders, "Power supply rejection for RF amplifiers,"
(RFIC) Symposium
, June 2006

Popovic,Zoya, “High efficiency microwave PA with dynamic power supplies”, ECEN 5014, Spring 2009, University of Colorado, Bou
lde
r

6

Amplifier Classes
-

A, AB,B, C, D,E,F

Conduction Angle, Efficiency

Niehenke,E, “GaN Power Amplifiers” Niehenke Consulting

7

Non Linear PA v Linear PA’s

Can’t do amplitude modulation Can
-

but highly inefficient



Stauth, Sanders, "Power supply rejection for RF amplifiers,"
(RFIC) Symposium
, June 2006

8

Average Efficiency

9

Solution?

Dynamic Power Supplies

10

Solution
-

Research Objective

•
HPA +Dynamic power supply MMIC

•
Use Triquint Semiconductor 0.25u GaN Process to
fabricate a monolithic solution.


MMIC Photo : Courtesy if Stephen Diebold, Karlshue Institute of Technology

11


Gallium Nitride
–

Materials & Devices

RF & Power Electronics



12

Properties of GaN

Niehenke,E, “GaN Power Amplifiers” Niehenke Consulting

13

Anomalous Behaviour
-

Traps

Development of virtual
gates wrecks havoc in
device performance

Ventury, R. “PhD Thesis defence”, UCSB.

14

Traps affecting FET performance

Kink effects I
DS

v V
DS

Shift in Threshold V
TH

RF Dispersion

A
LBAHRANI
,S.A

, “ C
HARACTERIZATION

OF

T
RAPPING

IN

G
ALLIUM

N
ITRIDE

HEMT
S
”, P
H
D T
HESIS
, M
ACQUARIE

U
NIVERSITY
, A
USTRALIA

2011

15

Device Engineering
-


Field Plates & Passivation

Niehenke,E, “GaN Power Amplifiers” Niehenke Consulting

16

MQ
-

Arbitrary Pulsed Semiconductor Parameter
Analyser System (APSPA)

17

Pulsed I
-
V Measurements

Understanding TQTX devices

18

Pulsed I
-
V Measurement (Cont.)

19

PA + High Efficiency Modulator

Design Options



Technology


FCC regulations


Cost


Modulation Schemes


20

Power Amplifier Biasing

21

Amplifier
–

Load
-
lines

Switching PA as Power Converters

22

Demonstration of Class E amplifier

Electrodeless Fluorescent Lamps


Demonstration of Resonant Inverter Circuit for Electrodeless Fluorescent Lamps Using High Voltage GaN
-
HEMT Wataru Saito*, Tomoka
zu Domon**, Ichiro Omura*, Tomohiro
Nitta*, Yorito Kakiuchi*, Kunio Tsuda*** and Masakazu Yamaguchi* * Semiconductor Company, Toshiba Corp **Toshiba Business and

Li
fe Service ***R&D Center, Toshiba Corp

1 Komukai Toshiba
-
cho, Saiwai
-
ku, Kawasaki 212
-
8583, Japan
Phone: +81
-
44
-
549
-
2603, FAX: +81
-
44
-
549
-
2883, e
-
mail: wataru3.saito@toshiba.co.jp

13.56 MHz Class E Amplifier

620V/ 1.4 A GaN HEMT
–

90% at 9W Output
Power

23

DC
-
DC Converter Architecture

Using switching PAs

DC
-
DC Converter fabricated using FET’s
non
-
optimized for power conversion

Popovic,Zoya, “High efficiency microwave PA with dynamic power supplies”, ECEN 5014, Spring 2009, University of Colorado, Bou
lde
r

24

PA and Modulator Integration Challenges
–

Power Supply Rejection Ratio (PSSR)

FCC has strict regulations
regarding this.

Selection of filters and switching
frequencies critical

Stauth
, Sanders, "Power supply rejection for RF amplifiers,"
(RFIC) Symposium
, June 2006

25


Triquint 0.25u GaN Process &

Circuit Designs

26

27

Circuits Design
-

Ring Oscillators, inverters, tuned amplifiers

28

Circuits Designed
-
MMIC Layout

Ring Oscillators, Inverters, Tuned Amplifiers

29

Further Work

•
Switching PA’s E/F

•
Class AB PA (16 Weeks)

•
Filters for noise rejection (8 Weeks)

•
Integration (20
-
24 Weeks)

•
Thermal Issues (16 Weeks)

•
Testing (14 Weeks)

30

Questions?