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Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

1

Design of Microwave Power
Amplifier with ADS



Technische Universität Berlin

Fachgebiet Mikrowellentechnik


Daniel Gruner, Ahmed Sayed, Ahmed Al Tanany, Khaled Bathich,

Henrique Portela, Amin Hamidian, Georg Boeck

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

2

Outline


Introduction



PA Overview



ADS Design Flow



Power Amplifier Design



Transistor Characterization



Hybrid Broadband Power Amplifier



Hybrid Doherty Power Amplifier



Hybrid Switch Mode Power Amplifier



Monolithic 6 GHz Power Amplifier



Monolithic 24 / 60 GHz Power Amplifier



Summary and Conclusion

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

3

Introduction

Microwave Engineering Laboratory, Berlin Institute of Technology






Research Focus

Hybrid Design


-

Power Amplifier (Broadband,


Doherty, Switch Mode…)


-

Characterization of passive and active devices


-

10/40 GHz Synthesizer


-

Distance measurement system


-

Local positioning system

MMIC Design


-

Power Amplifier (6 GHz, 24 GHz, 60 GHz…)


-

Modeling of passive mm wave structures


-

Characterization of integrated devices


-

RF front end design (6 GHz, 24 GHz, 60 GHz)


Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

4

PA Overview (1)


Power amplifiers (PAs) belong to the most challenging
function blocks in every communication system








PA is the last active part in a transmit system, followed by
the transmitting antenna


Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

5

PA Overview (2)


PA design for a huge variety of different standards,
frequency bands, power levels, device technologies…



Communication Applications Spectrum


f

[MHz]

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

6

PA Overview (3)


Performance Metrics




Output power:

strongly depend. on the load impedance




Efficiency:

measure for transformation of DC to RF energy



(PAE, Drain
-
/Collector
-
, overall efficiency)





Linearity:
IP3, ACPR, AM
-
AM/PM
-
Conversion




Maximum ratings:

guarantee max. temp., voltage, current…




Less important:

Small signal behavior, matching etc.

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

7

PA Overview (4)


Fundamental PA categories




L
inear PA



-

Classes A, B, AB, C




Switch Mode PA


-

Classes D, D
-
1, E, F, F
-
1, S, etc.




Combinations, extensions, smart transmitters


-

Power Combining, Doherty, Chireix, LINC, etc.

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

8

PA Overview (5)


Class A:



Conduction angle of 360
o



Linear operation



Low efficiency:

PAE
MAX

= 50% (
G
P



∞)

R
L

V
DD

Drive

and

Bias

V
GS

I
DS

V
p

0


V
DS

Load line

Bias point

I
max

I
max
/2

I
DS

V
DD

0

T/4

T/2

3T/4

T

V
knee

V
DD

2V
DD
-
V
knee

Voltage [V]





Current

Voltage

0

I
q

I
max

Current [A]

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

9

PA Overview (6)


Class B:



Conduction angle of 180
o



Less l
inear than class A



Increased efficiency:

PAE
MAX

= 78.5 %

I
DS

Bias point

I
max

V
P

0

V
DS

V
GS

I
DS

0

T/4

T/2

3T/4

T





Current

Voltage

0

I
max

V
knee

V
DD

2V
DD
-
V
knee

Voltage [V]

Current [A]

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

10

PA Overview (7)


Class AB:



Conduction angle: 180
°

<

Θ

< 360
°



Compromise between

class A and class B



Trade off between linearity and efficiency

0

T/4

T/2

3T/4

T

V
knee

V
DD

2V
DD
-
V
knee

Voltage [V]





Current

Voltage

0

I
max

Current [A]

V

GS

I

DS

V

p

I

max

Class AB

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

11

PA Overview (8)


Class C:



Conduction angle:

Θ < 180
°



Increased efficiency compared to class

B



but: decreased P
OUT


0

T/4

T/2

3T/4

T

V
knee

V
DD

2V
DD
-
V
knee

Voltage

[V]





Current

Voltage

0

I
max

Current

[A]

V

GS

I

DS

V

p

I

max

Class C

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

12


Increased efficiency



Reduced battery / power consumption








Lower cooling effort & extended active device lifetime








Reduced volume, weight and cost



Classical classes


-

Simultaneous voltage and current


-

Dissipation across the device


-

Limits practical efficiency



Switch mode classes


-

Non
-
overlapping waveforms


-

Dissipated power is low


-

High efficiency is enabled


-

Linearity is critical


PA Overview (9)

A

AB

SM

I
DS

I
MAX

I
Q

V
Knee

V
DD

2V
DD
-

V
Knee

V
DS

0

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

13

Doherty Power Amplifier



Efficiency of classical PAs


decreases in back
-
off region



Critical for modern wireless


standards with high PAR



Solution




Two PAs connected in parallel




Main PA (AB) and Peaking PA (C)




Load modulation




High efficiency is maintained


in back
-
off region







PA Overview (13)

P

out

E

f

f

i

c

i

e

n

c

y

P

sat

P
-
6 dB

sat

DPA

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

14

ADS Design Flow

ADS
Schematic
Design


Layout and
DRC


EM
Simulation of
Passive
Structures

ADS


EM/Co
Simulation

ADS
Schematic

Simulation

Redesign

Start

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

15

PA Design


Transistor Characterization (1)

Optimized amplifier performance




Maximization of P
out
, efficiency, linearity @ targeted input power / bias




Tuning (pulling) of the source and/or load impedance until optimum PA





Can be performed on simulation


and measurement level

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

16


Eudyna GaN
-
HEMT, 10 Watt, V
DD
= 48 V, I
D
= 120 mA

PA Design


Transistor Characterization (3)

Load
-
Pull, 2 GHz

Device Ref. Plane

Z
LOAD,OPT

@ 2
-
4 GHz

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

17


Measurement vs. ADS
-
Simulation, 10 W GaN
-
HEMT Eudyna















Good agreement between measurement and simulation

PA Design


Transistor Characterization (4)

Γ
SOURCE

f

= (2, 2.5, 3, 3.5, 4) GHz

Γ
LOAD

ADS
-
Simulation


Measurement

ADS
-
Simulation


Measurement

f

= (2, 2.5, 3, 3.5, 4) GHz

Z
OPT

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

18

PA Design


Hybrid Broadband PA (1)

Pout contours

P1

L1

TL22

C305

C306

C307

C308

C271

C270

C298

C269

DAC1

DAC

Term2

PORT1

TL96

TL3

Tee38

TL97

TL134

TL95

TL98

Tee39

TL94

SNP7

TL4

TL115

Tee45

Step 1: PA requirements

Step 2: Transistor selection

Step 3: Load/Source Pulling

Step 4: Networks verification

Step 5: Assembly



Meas. vs. ADS
-
Sim
ulation







Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

19

PA Design


Hybrid Broadband PA (2)

Network verification

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

20

PA Design


Hybrid Broadband PA (3)

BW [GHz]

0.001


3

Gain [dB]

12

OP
1dB

[dBm]

37

PAE [%]

22

OIP3 [dBm]

48



Example I: 5 W, 0.001


3 GHz PA

Transistor:

GaN
-
HEMT, Cree (packaged)

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

21



Example II: 5 W, 0.35


8 GHz PA

PA Design


Hybrid Broadband PA (4)

BW [GHz]

0.35


8

Gain [dB]

8
±

1.5

OP
1dB

[dBm]

37

PAE [%]

19

OIP3 [dBm]

51

Transistor:

GaN
-
HEMT, Cree (die)

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

22

DPA


Main PA


Class AB


Peaking PA


Class C




Eff. Enhancement


Design phases


ADS Schematic


ADS Momentum


Realization and measurement


Specifications


UMTS downlink (2.1 GHz )


P
out

> 50 W


PAE > 35% over 6
-
dB backoff


PA Design


Hybrid Doherty PA (1)

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

23

PA Design


Hybrid Doherty PA (2)

S
11
[dB]

-
8.5

S
21
[dB]

9.6

S
22
[dB]

-
9.9

Small signal measurements



ƒ
=2.1 GHz


Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

24

PA Design


Hybrid Doherty PA (3)

Large signal measurements




ƒ=2.1 GHz


G
ss

[dB]

9.6

OP
1dB

[dBm]

47.2 (52 W)

OP
SAT
[dBm]

49.4 (87 W)

η
max
[%]

55.0

PAE
max
[%]

45.0

η
6
-
dB
[%]

40.0

PAE
6
-
dB
[%]

34.0

Simulation
-

Solid lines

Measurement
-

Symbols

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

25

PA Design


Hybrid Switch Mode PA (1)

Switch mode classes


The output network creates non
-
overlapping waveforms


Dissipated power is low



High efficiency is enabled



Design of the device load network
is decisive


Specifications


UMTS application


High efficiency is required


Supply voltage 50 V


P
out

= 50 W


A

AB

SM

I
DS

I
MAX

I
Q

V
Knee

V
DD

2V
DD
-

V
Knee

V
DS

0

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

26

PA Design


Hybrid Switch Mode PA (2)

ADS Schematic design flow


Load
-
/Source
-
Pulling


Source



Targeted input power






Bias point (V
g


class B/AB)






Optimum impedances


Load




Harmonic load impedances as equation







Load Impedance for a class D
-
1

switch mode PA

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

27

PA Design


Hybrid Switch Mode PA (3)

Realization of class D
-
1

switch mode PA




Eudyna GaN
-
HEMT




3 dB hybrid coupler 90
o




Single stub OMN


R

Q
1

Q
2


S


S

Res.

OMN

Hybrid

90
o

Hybrid

90
o

S

IMN

λ
/4

λ
/4

50
Ω

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

28

PA Design


Hybrid Switch Mode PA (4)

Large signal results




P
out

= 47 dBm (50

W)


@ P
in

= 33

dBm




η

=
62.7

%




PAE = 60.3

%

meas

meas

meas

meas

sim

sim

sim

sim

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

29

PA Design


Monolithic 6 GHz PA (1)

Development of a fully integrated 6 GHz PA


Applications





6 GHz W
ireless LAN




Vehicular environments
(IEEE P802.11p)



Linear power amplifier



Class AB operation



Push
-
Pull topology



Low supply voltage



SiGe HBT technology

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

30

PA Design


Monolithic 6 GHz PA (2)


PA performance degrades with larger
transistor arrays






Power combining of several efficient PA


stages with decreased transistor size



Integrated transformer is used as power
combiner



Transformer design using ADS
-
Momentum





PA design using EM/Co simulation in ADS

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

31

PA Design


Monolithic 6 GHz PA (3)


Realized 5.6
-

6.4 GHz power amplifier

1.6 mm

1.3 mm

P
IN

[dBm]

P
OUT

[dBm]

PAE [%]

V
DD
= 1.8 V

V
DD
= 1.2 V

f

= 6 GHz

Freq.

[GHz]

V
DD

[V]

OP1dB

[dBm]

OPsat

[dBm]

Eta
MAX

[%]

PAE
max

[%]

SS Gain

[dB]

6

1.8

21

24

28.5

25

12

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

32

PA Design


Monolithic 24 / 60 GHz PA (1)


24 GHz

ISM band




Industrial, scientific and medical applications



Targets




Gain > 13.5 dB




OP
1dB

> 11 dBm




PAE > 15 %

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

33


Technology




0.18
μ
m CMOS



Amplifier topology




2 Stage cascode amplifier




Simplified on
-
chip impedance
matching using bias network to match
the impedance.



Design procedure




Circuit simulation on ADS




Layout in cadence




EM/Co simulation on ADS

V
bias

RF
in

PA Design


Monolithic 24 / 60 GHz PA (2)

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

34

PA Design


Monolithic 24 / 60 GHz PA (3)

Cadence Layout

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

35

PA Design


Monolithic 24 / 60 GHz PA (3)

Momentum simulation

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

36

PA Design


Monolithic 24 / 60 GHz PA (3)

Momentum simulation

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

37

PA Design


Monolithic 24 / 60 GHz PA (3)

ADS EM/Co Simulation

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

38

PA Design


Monolithic 24 / 60 GHz PA (3)

ADS EM/Co Simulation

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

39

PA Design


Monolithic 24 / 60 GHz PA (3)

Microphotograph of the PA die

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

40

PA Design


Monolithic 24 / 60 GHz PA (4)


Measures




Good agreement between simulation
and measurements



Freq. [GHz]

26.5

V
DD

[V]

3.0

OP1dB [dBm]

13.5

OPsat [dBm]

17.5

PAE @ P
1dB

[%]

12.3

Peak PAE [%]

22.5

Chip size [mm
2]

0.73 x 1.15

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

41


60 GHz power amplifier




H
igh oxygen loss at 60 GHz




Appropriate for indoor or short range wireless communication



60 GHz band



PA Design


Monolithic 24 / 60 GHz PA (5)



Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

42

PA Design


Monolithic 24 / 60 GHz PA (6)


Requirements


High Power


High OP1dB


High PAE


High Gain


Selected Topology


Parallel stages


High Power Matching


Two Stage


Cascode

}

}

IN

IN

IMN

OMN

Biasing

Circuit

Biasing

Circuit

Matching

Circuit

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

43

Z
Opt

50
Ω


Matching network

PA Design


Monolithic 24 / 60 GHz PA (7)

Z
Opt


Step 2: Selection of T.L.s, Inductors and Capacitors

Step 3: EM simulation of matching network

Step 1: Load and source pull simulation


Matching for optimum OP1dB

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

44

PA Design


Monolithic 24 / 60 GHz PA (8)

Freq.

[GHz]

Gain
[dB]

OP
1dB

[dBm]

OP
sat

[dBm]

PAE

[%]

61.0

18.8

14.5

15.5

19.7



60 GHz PA achievements




High Power



High Linearity



High PAE



High Gain



Measurements

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

45

Summary and Conclusion


Excellent results using presented ADS PA design flow



Good agreement between EM/Co simulations and
measurements



Applicable up to mm wave frequencies



Design procedure has been demonstrated for various PAs



Hybrid Broadband Power Amplifier



Hybrid Doherty Power Amplifier



Hybrid Switch Mode Power Amplifier



Monolithic 6 GHz Power Amplifier



Monolithic 24 / 60 GHz Power Amplifier

Gruner, ADS User Meeting 09

Technische Universität Berlin

Microwave Engineering

46

Summary and Conclusion

Thanks