MICS RFIC Group 1
High efficiency Power amplifier design for mm-Wave
Seyed Yahya Mortazavi
MICS RFIC Group 2
Outline
Introduction: Power amplifier (PA) Metrics Class A, AB, B, C Pas
High efficiency Class F Pas mm-Wave PA applications mm-Wave PA challenges and survey Our Designs: Steps, Simulations results Conclusions and future works
MICS RFIC Group 3
Power amplifier basics
Metrics: Gain: Efficiency: Power Added Efficiency:
r
CB
50
oh
m
r
r
CB
VCC
50
oh
m
AC block
Output Mathcing
InputMatching
II
ImIDMVDM
Vm
MICS RFIC Group
Power amplifier basics
4
A
AB
BC
VBE
AABBC
VCE
A AB B C
ICIC
time
Gain and Efficiency trade-off: Class A: highest gain and linearity Class C: highest efficiency …..
MICS RFIC Group 5
0 20 40 60 80 100 120 140 160 1800
0.2
0.4
0.6
0.8
IC0
IC1
PA basics
-100 0 1000
0.2
0.4
0.6
0.8
1
IC
Conduction angle (CA)ωt
CA
0 20 40 60 80 100 120 140 160 1801
1.2
1.4
1.6
1.8
2
Conduction angle (CA)
IC0 , IC1
𝐼𝐶 1𝐼𝐶 0
MICS RFIC Group 6
PA basics
High efficiency PAs Class E, switching PAs Class F
𝜂=𝑃𝑜𝑢𝑡 ,1 𝑓
𝑃𝑑𝑐
=𝑃𝑜𝑢𝑡 ,1 𝑓
𝑃𝑑𝑖𝑠𝑠+𝑃𝑜𝑢𝑡 ,1 𝑓 +∑𝑛=2
∞
𝑃𝑜𝑢𝑡 ,𝑛 𝑓
0 0.2 0.4 0.6 0.8 10
0.5
1
0 0.2 0.4 0.6 0.8 10
0.5
1
ω0 t
𝑍 𝐿 ,𝑛𝑓=|𝑍 𝐿,𝑛𝑓|𝑒− 𝑗𝜑 𝑛
𝑖𝑐𝑣𝑐
MICS RFIC Group 7
Class F PAs
Uses harmonics to Reduce Vce for same fundamental: same output power with less dissipated power.
F3: F2: F35: F24:
-0.5 0 0.5 1 1.5-1
-0.5
0
0.5
1
Vdsfundumental3rd H
Vce
0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.40.7
0.8
0.9
1
Maximally Flat (F3)Maximum Efficiency (F3)
Vce
time
time
CB
Ro
pt
r
r
CB
VCC
50 o
hm
r AC block
VBB
AC block
Matching
r
L1C1
Harmonic filtering
r
L3h
C3h
3rd Harmonic filter
MICS RFIC Group 8
Class F PA
F3 F2 F35 F2478
80
82
84
86
88
90
92
94
96
98
η(Maximally Flat)η(Max Efficiency)
1.12, 1.15Pi/2,
1.33,1.41Pi/4
1.17,1.207Pi/2
1.42,1.5Pi/4
Vm/Vdc
Im/Idc
MICS RFIC Group 9
mm-Wave PAs Application
Data Communication (based on FCC frequency allocation): 59-64 GHz (V-band), 71-76 GHz, 81-86 GHz (E-bands), and 92-95 GHz (W-bands)
77 GHz Automotive Radars
> 77 GHz Active Imaging: Security gates, Medical Imaging
applications, Radar systems,
MICS RFIC Group 10
CB
r
CB
VCC
r AC blockAC block
RL
Cp
Si-based mm-Wave PAs
Low Break-down voltage: Reduces output voltage swing: smaller output power or gain
More sensitive to parasitics: Parasitics have Lower impedance as frequency increase
Close to fT of transistor: Lower power gain and PAE
VCE
IC
BVCO
MICS RFIC Group
Si-based mm-wave PAs
11
30 40 50 60 70 80 90 100 11005
10152025303540
30 40 50 60 70 80 90 100 1100
5
10
15
20
25
Frequency (GHz)Frequency (GHz)
Po
ut
(dB
m)
PA
E (
%)
30 40 50 60 70 80 90 1000
5
10
15
20
25
CMOS And SiGe PAs
SiGe PAs
30 40 50 60 70 80 90 10005
101520253035
Frequency (GHz)Frequency (GHz)
Po
ut
(dB
m)
PA
E (
%)
MICS RFIC Group
Si-based mm-wave PAs
12
Frequency (GHz)
Gai
n(d
B)
CMOS And SiGe PAs
SiGe PAs
Frequency (GHz)
Gai
n (
dB
)
30 40 50 60 70 80 90 100 11005
101520253035
30 40 50 60 70 80 90 1000
5
10
15
20
25
30
MICS RFIC Group 13
Review- VCE > BVCO
79GHz, PAE~ 13.5%, Pout ~ 17.7 dBm, Gain~14 dB, Class AB The external base impedance seen from Q1, Q2, and Q3 is small at
Wband frequencies. The resulting effective collectoremitter breakdown voltage allows the output voltage at the collectors to peak above 4.2 V, a factor of 2.5 improvement over BVceo.
RFIC-2008
MICS RFIC Group 14
Review- Cascoding
77GHz, PAE~ 7.5%, Pout ~ 15 dBm, Gain~22.5 dB, Class AB the CAS topology was preferred to achieve a higher stable gain,
better reverse isolation, and improved robustness. A large output voltage swing is tolerated by the CB ( > BVCO) if
it is driven with a low base resistance.
TMTT-2011
MICS RFIC Group 15
Review- Current reuse
77GHz, PAE~ 9%, Pout ~ 14.5 dBm, Gain~25 dB, Class AB Current reuse at Driver stage
TMTT-2012
MICS RFIC Group 16
PA design Steps
DC simulations for Knee and BVCO voltages for estimating maximum voltage swing (Vpp),
Calculation and simulations for finding transistor size and DC bias current for Class A PA regarding Vpp and required Pout ,
Current density for max fT is 8~11 mA/um for SiGe HBTs.
Input matching for selected size and bias point, Iterative Load-pull simulations for determining parasitic
capacitance (Cce or Cp) and verifying Ropt , Changing bias from class A to class AB for max efficiency
and Gain, Adjusting Ropt Output matching,
MICS RFIC Group 17
PA design Steps
Bias for class A, Ropt for Load-line Power matching vs conjugate power
matching
MICS RFIC Group 18
PA design Steps
Input matching and load pull (94GHz PA) Load-pull simulation is done for different
Lp to get the optimum point over pure realImpedance
r
VCC
r AC block
VBB
AC block
Cp
r
CB
50
oh
m
Matching
Γ
r
Lp
MICS RFIC Group 19
PA design StepsChanging bias point from A to AB
VBE VBE
PA
E (
%)
PA
E (
%)
Pin (dBm) Rout (Ω)
Rout=38ΩPin = 11 dBm
r
VCC
r AC block
VBB
AC block
Cp
r
CB
50
ohm Matching
r
Lp
Rout
CB
VBE (mV)
PA
E (
%)
Ga
in (
dB
)
Rout=38Ω, Pin=0, 11 dBm
MICS RFIC Group 20
Utilizing 3rd H for efficiency (F3)
r
VCC
r AC block
VBB
AC block
Cp
r
CB
50 o
hm Matching
Ropt
CBOutput Network
MICS RFIC Group 21
Utilizing 3rd H for efficiency (F3)
r
r
VCC
Cp
r
CB
50 o
hm Matching
Ropt
CB
Lp
L3H
C3H
r
VCC
Cp
r
CB
50 o
hm Matching
Ropt
CB
L1
L3H
C3H
C2
r
rL2
MICS RFIC Group 22
Utilizing 3rd H for efficiency (F3)
Po
ut
(dB
m)
PA
E (
%)
Pd
issp
(m
W)
ABF3-filter
F3-Harmonic Control
Pin (dBm) Pin (dBm)
MICS RFIC Group 23
Utilizing 3rd H for efficiency (F3)
r
C3H
L3H
rrL1H
L1H
C1H
C1H
L3H
TL
VCC
r
CB CMI
LMI
RB2RB1
Rref
VBB
50 o
hm
r
r
CB
50 o
hmCMO
LMO
Q2Q1
MICS RFIC Group 24
Utilizing 3rd H for efficiency (F3)
Po
ut
(dB
m)
PA
E (
%)
Pd
issp
(m
W)
Pin (dBm) Pin (dBm)
Pin (dBm)
MICS RFIC Group 25
94 GHz 1-Stage Class-F PA (VCC = 1.3V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~10 dBm, Psat: ~11.5 dBm PAE: max 15-16 %
MICS RFIC Group 26
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =15.3%
P-1dB = 7.7dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22
S11
S21
94 GHz 1-Stage Class-F PA (VCC = 1.3V): Simulations
MICS RFIC Group 27
94 GHz 1-Stage Class-F PA (VCC = 1.3V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 535μm x 390μm
MICS RFIC Group 28
94 GHz 1-Stage Class-F PA (VCC = 2.2V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~15 dBm, Psat: ~16 dBm PAE: max 21-22 %
MICS RFIC Group 29
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =21.8%
P-1dB = 11.9dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22S11
S21
94 GHz 1-Stage Class-F PA (VCC = 2.2V): Simulations
MICS RFIC Group 30
94 GHz 1-Stage Class-F PA (VCC = 2.2V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
Size: 530μm x 400μm
gnd
gnd
MICS RFIC Group 31
94 GHz 2-Stage Class-F PA: Schematic
Class-F, 2-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~16 dBm, Output Psat: ~17 dBm PAE: max 21-22 %
MICS RFIC Group 32
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =22%
P-1dB = 9.1dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22 S11
S21
94 GHz 2-Stage Class-F PA : Simulations
MICS RFIC Group 33
94 GHz 2-Stage Class-F PA : Layout
VBB1 VCC1 gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
VCC2 VBB2 gndgnd
Size: 670μm x 490μm
MICS RFIC Group 34
60 GHz 1-Stage Class-F PA with coupled harmonic control: Schematics
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~12.8 dBm, Psat: ~15 dBm PAE: max 25-26 %
MICS RFIC Group 35
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =25.5%
P-1dB = 7.7dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22
S11
S21
60 GHz 1-Stage Class-F PA with coupled harmonic control: Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~15 dBm Psat with 25-26% PAE.
MICS RFIC Group 36
60 GHz 1-Stage Class-F PA with coupled harmonic control: Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 710μm x 410μm
MICS RFIC Group 37
Design Summary
94GHz PAE (%) IP1dB (dBm) Psat (dBm) Gain (dB)
1stage-1.3V 15.3 7.7 12.5 3.8
1stage-2.2V 21.8 11.9 17 4
2stage 22 9.1 17 7.8
60GHz PAE (%) P1dB (dBm) Psat (dBm) Gain (dB)
1stage-1.3V 25.8 5.5 12.5 6.5
1stage-2.2V 29 9.7 17 7
2stage 28.5 4.2 16 11.5
33GHz PAE (%) P1dB (dBm) Psat (dBm) Gain (dB)
1stage-1.3V 30 2.5 11 7
1stage-2.2V 40 4 15 10
MICS RFIC Group
Si-based mm-wave PAs
38
30 40 50 60 70 80 90 1000
5
10
15
20
25 SiGe PAs
30 40 50 60 70 80 90 10005
10152025303540
Frequency (GHz)
Po
ut
(dB
m)
PA
E (
%)
Frequency (GHz)
Frequency (GHz)
Gai
n (
dB
)
30 40 50 60 70 80 90 1000
5
10
15
20
25
30
MICS RFIC Group 39
Future Works
Increasing gain using efficient driving stages Increasing gain using Power combining techniques Improving quality factor of Capacitors using MOM caps Class E PAs
MICS RFIC Group 40
60 GHz 1-Stage Class-F PA (VCC = 1.3V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~11 dBm, Psat: ~12.5 dBm PAE: max 25-26 %
MICS RFIC Group 41
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =25.8%
P-1dB = 5.5dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22S11
S21
60 GHz 1-Stage Class-F PA (VCC = 1.3V): Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~12.5 dBm Psat with 25-26% PAE.
MICS RFIC Group 42
60 GHz 1-Stage Class-F PA (VCC = 1.3V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 610μm x 410μm
MICS RFIC Group 43
60 GHz 1-Stage Class-F PA (VCC = 2.2V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~9.7 dBm, Psat: ~15 dBm PAE: max 29-30 %
MICS RFIC Group 44
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =29%
P-1dB = 9.7dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22S11
S21
60 GHz 1-Stage Class-F PA (VCC = 2.2V): Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~16 dBm Psat with 29-30% PAE.
MICS RFIC Group 45
60 GHz 1-Stage Class-F PA (VCC = 2.2V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
Size: 575μm x 410μm
gnd
gnd
MICS RFIC Group 46
60 GHz 2-Stage Class-F PA : Schematic
Class-F, 2-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~15 dBm, Psat: ~16 dBm PAE: max 28-29 %
MICS RFIC Group 47
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =28.5%
P-1dB = 4.2dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22
S11
S21
60 GHz 2-Stage Class-F PA : Simulations
MICS RFIC Group 48
60 GHz 2-Stage Class-F PA : Layout
VBB1 VCC1 gndgnd
rfIn rfOut
gnd
gnd
gnd
gnd
VBB2 VCC2 gnd
Size: 900μm x 400μm
MICS RFIC Group 49
33 GHz 1-Stage Class-F PA (VCC = 1.3V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~11 dBm, Psat: ~10.5 dBm PAE: max 29-30 %
MICS RFIC Group 50
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =30%
P-1dB = 2.5dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22
S11
S21
33 GHz 1-Stage Class-F PA (VCC = 1.3V): Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~10.5 dBm Psat with 29-30% PAE.
MICS RFIC Group 51
33 GHz 1-Stage Class-F PA (VCC = 1.3V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 615μm x 440μm
MICS RFIC Group 52
33 GHz 1-Stage Class-F PA (VCC = 2V): Schematic
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~9.7 dBm, Psat: ~15 dBm PAE: max 29-30 %
MICS RFIC Group 53
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =40%
P-1dB = 4dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22 S11
S21
33 GHz 1-Stage Class-F PA (VCC = 2V): Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~15 dBm Psat with 39-40% PAE.
MICS RFIC Group 54
33 GHz 1-Stage Class-F PA (VCC = 2V): Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
Size: 620μm x 440μm
gnd
gnd
MICS RFIC Group 55
60 GHz 1-Stage Class-F PA with coupled harmonic control: Schematics
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~12.8 dBm, Psat: ~15 dBm PAE: max 25-26 %
MICS RFIC Group 56
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =25.5%
P-1dB = 7.7dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22
S11
S21
60 GHz 1-Stage Class-F PA with coupled harmonic control: Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~15 dBm Psat with 25-26% PAE.
MICS RFIC Group 57
60 GHz 1-Stage Class-F PA with coupled harmonic control: Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 710μm x 410μm
MICS RFIC Group 58
33 GHz 1-Stage Class-F PA with coupled harmonic control: Schematics
Class-F, 1-stage design: 2nd & 3rd harmonic controls Harmonic filter: high-Z for fund & 3rd-harmonic, low-Z for 2nd-harmonic OP-1dB: ~12.8 dBm, Psat: ~15 dBm PAE: max 25-26 %
r
C3H
L3H
rrL1H
L1H
C1H
C1H
L3H
TL
1.5V
r
CB CMI
LMI
RB2RB1
Rref
50
oh
m
r
r
CB
50
oh
mCMO
LMO
Q2
r
C2H
L2HVBB
Harmonic filter
Z-matching
Z-matching
biasing
MICS RFIC Group 59
Pou
t (d
Bm
)
Pin (dBm)PA
E (
%)
PAEmax =32%
P-1dB = 10.2dBm
S-p
ara
mete
r (d
B)
Freq (GHz)
S22 S11
S21
33 GHz 1-Stage Class-F PA with coupled harmonic control: Simulations
These are simulation results including layout sonnet EM-model. Single stage design has ~12.5 dBm Psat with 31-32% PAE.
MICS RFIC Group 60
33 GHz 1-Stage Class-F PA with coupled harmonic control: Layout
VBB VCC gndgnd
gnd
gnd
rfIn rfOut
gnd
gnd
Size: 670μm x 430μm
MICS RFIC Group 61
Utilizing 3rd H for efficiency (F3)
Po
ut
(dB
m)
PA
E (
%)
Pd
issp
(m
W)
Ic (
mA
)
Vce
(V
)
time (ps)
AB
F3-filterF3-Harmonic Control
ABF3-filter
F3-Harmonic Control
Pin (dBm) Pin (dBm)