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Class-S Power Amplifier Concept for MobileCommunications in Rural Areas with Concurrent
Transmission at 450 MHz and 900 MHz
Martin Schmidt, Johannes Digel, Manfred Berroth
Institute of Electrical and Optical Communications Engineering
University of Stuttgart
Stuttgart, Germany
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
1
2011 c© M. Schmidt/INT
Outline
MotivationChallenges for basestation suppliersClass-S principle
ArchitectureModulator lowpass prototypeMulti path transform5 path transform spectrum and SNR
Concurrent Transmission in both Frequency BandsOutput spectrumComparison of notches of both frequency bands
StabilityStability vs. input amplitudesExplanation of stability limit
Coding EfficiencyTotal output power and signal output powerSingle tone coding efficiency and combined coding efficiency
ConclusionUniversity of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
2
2011 c© M. Schmidt/INT
Motivation
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
3
2011 c© M. Schmidt/INT
Motivation: Flexibility is Key
Challenges: High requirements . . .• Increasing number of standards,
(GSM, UMTS, CDMA2000, LTE, . . . )
• frequency bands(450 MHz, 900 MHz, 2.1 GHz)
• and use cases(coverage vs. data rate)
• in different markets.(Europe, North America, China, . . . )
Need for flexibility
. . . and high design efforts and costs.• Analog properties in advanced CMOS
technologies deteriorate
• Development in advanced CMOSnodes is expensive
and better designs /less design cycles
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
4
2011 c© M. Schmidt/INT
Motivation: Flexibility is Key
Challenges: High requirements . . .• Increasing number of standards,
(GSM, UMTS, CDMA2000, LTE, . . . )
• frequency bands(450 MHz, 900 MHz, 2.1 GHz)
• and use cases(coverage vs. data rate)
• in different markets.(Europe, North America, China, . . . )
Need for flexibility
. . . and high design efforts and costs.• Analog properties in advanced CMOS
technologies deteriorate
• Development in advanced CMOSnodes is expensive
and better designs /less design cycles
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
4
2011 c© M. Schmidt/INT
Motivation: Flexibility is Key
Challenges: High requirements . . .• Increasing number of standards,
(GSM, UMTS, CDMA2000, LTE, . . . )
• frequency bands(450 MHz, 900 MHz, 2.1 GHz)
• and use cases(coverage vs. data rate)
• in different markets.(Europe, North America, China, . . . )
Need for flexibility
. . . and high design efforts and costs.• Analog properties in advanced CMOS
technologies deteriorate
• Development in advanced CMOSnodes is expensive
and better designs /less design cycles
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
4
2011 c© M. Schmidt/INT
Motivation: Flexibility is Key
Challenges: High requirements . . .• Increasing number of standards,
(GSM, UMTS, CDMA2000, LTE, . . . )
• frequency bands(450 MHz, 900 MHz, 2.1 GHz)
• and use cases(coverage vs. data rate)
• in different markets.(Europe, North America, China, . . . )
Need for flexibility
. . . and high design efforts and costs.• Analog properties in advanced CMOS
technologies deteriorate
• Development in advanced CMOSnodes is expensive
and better designs /less design cycles
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
4
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
Bandpass Delta Sigma Modulator
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
HF
LO
090
Conventional Heterodyne Transmitter
BasebandProcessor
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
The class-S amplifier concept is a “Software Defined Radio” solution.In general it• offers flexibility,
• low design effort,
• low power consumption and
• reduces number of analog components.
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
• This presentation is about a special system for concurrent transmission inthe 450 MHz and the 900 MHz band.
• Main benefit: One solution for different use cases - coverage vs. data rate
• Only Bandpass Delta Sigma Modulator is treated here
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Motivation: Class-S Amplifier
BasebandProcessor
Upsamplerand Mixer
BPDSMSwitching-mode PA
AnalogFilter
Class-S Transmitter
• This presentation is about a special system for concurrent transmission inthe 450 MHz and the 900 MHz band.
• Main benefit: One solution for different use cases - coverage vs. data rate
• Only Bandpass Delta Sigma Modulator is treated here
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
5
2011 c© M. Schmidt/INT
Modulator Architecture
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
6
2011 c© M. Schmidt/INT
Modulator Lowpass Prototype
z−1
−1/16 −1/4
X Y
z−1
z−1
−1/2
−1/32
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
7
2011 c© M. Schmidt/INT
Lowpass Prototype Output Spectrum
0 0.2 0.4 0.6 0.8 1−140
−120
−100
−80
−60
−40
−20
0
Normalized Frequency / fs
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
8
2011 c© M. Schmidt/INT
Modulator Architecture
z−1
−1/16 −1/4
X Y
z−1
z−1
−1/2
−1/32
transform z−1 → z−n
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
9
2011 c© M. Schmidt/INT
Modulator Architecture
z− 1
−1/16 −1/4
X Y
z− 1
z− 1
−1/2
−1/32
z− n
−1/16 −1/4
X Y
z− n
z− n
−1/2
−1/32
transform z− 1 → z− n
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
9
2011 c© M. Schmidt/INT
Modulator Architecture
z− n
−1/16 −1/4
X Y
z− n
z− n
−1/2
−1/32
X Y
LPDSM
LPDSM
LPDSM
1:n
DE
MU
X
n:1
MU
X
equivalent
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
9
2011 c© M. Schmidt/INT
Modulator Architecture
0 0.2 0.4 0.6 0.8 1−140
−120
−100
−80
−60
−40
−20
0
Normalized Frequency / fs
Ou
tpu
t p
ow
er
[dB
]
0 0.2 0.4 0.6 0.8 1−140
−120
−100
−80
−60
−40
−20
0
Normalized Frequency / fs
Ou
tpu
t p
ow
er
[dB
]
0 0.2 0.4 0.6 0.8 1−140
−120
−100
−80
−60
−40
−20
0
Normalized Frequency / fs
Ou
tpu
t p
ow
er
[dB
]
0 0.2 0.4 0.6 0.8 1−140
−120
−100
−80
−60
−40
−20
0
Normalized Frequency / fs
Ou
tpu
t p
ow
er
[dB
]
n=2 n=3
n=4 n=5
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
10
2011 c© M. Schmidt/INT
Output Spectrum for Transform with n=5
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
11
2011 c© M. Schmidt/INT
Output Spectrum for Transform with n=5
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
11
2011 c© M. Schmidt/INT
Signal-to-Noise-Ratio of Single Sinusoids in Both Frequency Bands
0 10 20 30 40 50 6035
40
45
50
55
60
65
70
75
80
85
Bandwidth [MHz]
SN
R [dB
]
SNR @ 450 MHz
SNR @ 900 MHz
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
12
2011 c© M. Schmidt/INT
Concurrent Transmission in Frequency Bandsat 450 MHz and at 900 MHz
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
13
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Output Spectrum for Concurrent Transmission
0 0.5 1 1.5 2
−120
−100
−80
−60
−40
−20
0
Frequency [GHz]
Ou
tpu
t p
ow
er
[dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
14
2011 c© M. Schmidt/INT
Zoom into Output Spectrum for Frequency Bands @1/5, 2/5fs
455.6 458.6 461.7 464.7 467.7 470.7 473.8 476.8 479.8 482.9 485.9 488.9
−100
−80
−60
−40
−20
0
Frequency 460MHz .. 467MHz−band [MHz]
928 931 934 937.1 940.1 943.1 946.2 949.2 952.2 955.2 958.3 961.3
−100
−80
−60
−40
−20
0
Frequency 935MHz .. 960MHz−band [MHz]
No
rma
lize
d O
utp
ut
Po
we
r [d
B]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
15
2011 c© M. Schmidt/INT
Stability
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
16
2011 c© M. Schmidt/INT
Area of Stability: Definition
0 10 20 30 40 50 6035
40
45
50
55
60
65
70
75
80
85
Bandwidth [MHz]
SN
R [
dB
]
SNR @ Amplitudein
=3300• Modulator is considered
stable until SNR@bandwidth≈20 MHzdrops by 3dB frommaximum SNR at thispoint
• Here:
SNR(3400)+3 dB>SNR(3300)SNR(3500)+3 dB>SNR(3400)SNR(3600)+3 dB<SNR(3500)⇒ instable
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
17
2011 c© M. Schmidt/INT
Area of Stability: Definition
0 10 20 30 40 50 6035
40
45
50
55
60
65
70
75
80
85
Bandwidth [MHz]
SN
R [
dB
]
SNR @ Amplitudein
=3300
SNR @ Amplitudein
=3400
• Modulator is consideredstable until SNR@bandwidth≈20 MHzdrops by 3dB frommaximum SNR at thispoint
• Here:SNR(3400)+3 dB>SNR(3300)
SNR(3500)+3 dB>SNR(3400)SNR(3600)+3 dB<SNR(3500)⇒ instable
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
17
2011 c© M. Schmidt/INT
Area of Stability: Definition
0 10 20 30 40 50 6035
40
45
50
55
60
65
70
75
80
85
Bandwidth [MHz]
SN
R [
dB
]
SNR @ Amplitudein
=3300
SNR @ Amplitudein
=3400
SNR @ Amplitudein
=3500
• Modulator is consideredstable until SNR@bandwidth≈20 MHzdrops by 3dB frommaximum SNR at thispoint
• Here:SNR(3400)+3 dB>SNR(3300)SNR(3500)+3 dB>SNR(3400)
SNR(3600)+3 dB<SNR(3500)⇒ instable
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
17
2011 c© M. Schmidt/INT
Area of Stability: Definition
0 10 20 30 40 50 6035
40
45
50
55
60
65
70
75
80
85
Bandwidth [MHz]
SN
R [
dB
]
SNR @ Amplitudein
=3300
SNR @ Amplitudein
=3400
SNR @ Amplitudein
=3500
SNR @ Amplitudein
=3600
• Modulator is consideredstable until SNR@bandwidth≈20 MHzdrops by 3dB frommaximum SNR at thispoint
• Here:SNR(3400)+3 dB>SNR(3300)SNR(3500)+3 dB>SNR(3400)SNR(3600)+3 dB<SNR(3500)⇒ instable
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
17
2011 c© M. Schmidt/INT
Area of Stability
0 500 1000 1500 2000 2500 3000 3500 40000
500
1000
1500
2000
2500
3000
3500
Amplitude @f=1/5fs
Am
plit
ud
e @
f=2
/5f s
Stability limit for signal @f=1/5fs
Stability limit for signal @f=2/5fs
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
18
2011 c© M. Schmidt/INT
Explanation of Stability Limit
0 2 4 6 8 10
−1
−0.5
0
0.5
1
1.5
2
2.5
3
Discrete Time
No
rma
lize
d A
mp
litu
de
sinusoid @f=1/5fs
sinusoid @f=2/5fs
combination of sinusoids
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
19
2011 c© M. Schmidt/INT
Explanation of Stability Limit
0 2 4 6 8 10
−1
−0.5
0
0.5
1
1.5
2
2.5
3
Discrete Time
No
rma
lize
d A
mp
litu
de
sinusoid @f=1/5fs
sinusoid @f=2/5fs
combination of sinusoids
Sampling instants ofone lowpass modulator
X Y
LPDSM
LPDSM
LPDSM
LPDSM
LPDSM
1:5
DE
MU
X
5:1
MU
X
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
19
2011 c© M. Schmidt/INT
Coding Efficiency
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
20
2011 c© M. Schmidt/INT
Total Output Power and Signal Power (Separate & Combined)
Power spectral density
SDT(k) =
∣∣∣∣ 1√NFFT
∑NFFT−1n=0 x(n)e
−j2πNFFT
nk∣∣∣∣
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
21
2011 c© M. Schmidt/INT
Total Output Power and Signal Power (Separate & Combined)
(0,0) (1,0) (0,1) (0,0)0
0.2
0.4
0.6
0.8
1
1.2
Normalized Amplitude (@f=1/5fs,@f=2/5f
s)
Norm
aliz
ed P
ow
er
Normalized total output power
Normalized signal output power
Normalized single tone output powerTotal output power
SDT(k) =
∣∣∣∣ 1√NFFT
∑NFFT−1n=0 x(n)e
−j2πNFFT
nk∣∣∣∣
Ptot =∑NFFT−1
n=0 x2(n) =∑NFFT−1
k=0 S2DT(k)
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
21
2011 c© M. Schmidt/INT
Total Output Power and Signal Power (Separate & Combined)
(0,0) (1,0) (0,1) (0,0)0
0.2
0.4
0.6
0.8
1
1.2
Normalized Amplitude (@f=1/5fs,@f=2/5f
s)
Norm
aliz
ed P
ow
er
Normalized total output power
Normalized signal output power
Normalized single tone output powerSignal output power
SDT(k) =
∣∣∣∣ 1√NFFT
∑NFFT−1n=0 x(n)e
−j2πNFFT
nk∣∣∣∣
Ptot =∑NFFT−1
n=0 x2(n) =∑NFFT−1
k=0 S2DT(k)
SCT(k) = sinc(
kNFFT
)SDT(k)
Psig = S2CT(k1) + S2
CT(k2)
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
21
2011 c© M. Schmidt/INT
Coding Efficiency
(0,0) (1,0) (0,1) (0,0)0
5
10
15
20
25
30
35
Normalized Amplitude (@f=1/5fs,@f=2/5f
s)
Codin
g E
ffic
iency [%
]
Combined output power
single tone output power Coding efficiency
SDT(k) =
∣∣∣∣ 1√NFFT
∑NFFT−1n=0 x(n)e
−j2πNFFT
nk∣∣∣∣
Ptot =∑NFFT−1
n=0 x2(n) =∑NFFT−1
k=0 S2DT(k)
SCT(k) = sinc(
kNFFT
)SDT(k)
Psig = S2CT(k1) + S2
CT(k2)
ηc =PsigPtot
=S2
CT(k1)+S2CT(k2)∑NFFT−1
n=0 x2(n)
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
22
2011 c© M. Schmidt/INT
Coding Efficiency vs. Input Amplitudes
00.2
0.40.6
0.81
0
0.5
10
10
20
30
40
NormalizedAmplitude @f=2/5f
s
NormalizedAmplitude @f=1/5f
s
Codin
g E
ffic
iency [%
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
23
2011 c© M. Schmidt/INT
Conclusion
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
24
2011 c© M. Schmidt/INT
Conclusion
Summary• Class-S transmitter offers high flexibility and low design effort
• For single tone transmission 60 dB SNR in 30 MHz bandwidth possible inboth frequency bands
• Concurrent transmission in the two important frequency bands 450 MHzand 900 MHz
• Stability depends on sum of input amplitudesdue to positive interference at one of the five low pass modulators
• Combined coding efficiency is better than coding efficiency for single toneexcitation
Outlook• Analysis of linearity
• Probability density function of output pulse widths (memory effect inpower amplifier)
• Average transition frequency (switching losses in power amplifier)
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
25
2011 c© M. Schmidt/INT
Conclusion
Summary• Class-S transmitter offers high flexibility and low design effort
• For single tone transmission 60 dB SNR in 30 MHz bandwidth possible inboth frequency bands
• Concurrent transmission in the two important frequency bands 450 MHzand 900 MHz
• Stability depends on sum of input amplitudesdue to positive interference at one of the five low pass modulators
• Combined coding efficiency is better than coding efficiency for single toneexcitation
Outlook• Analysis of linearity
• Probability density function of output pulse widths (memory effect inpower amplifier)
• Average transition frequency (switching losses in power amplifier)University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
25
2011 c© M. Schmidt/INT
Thank you for your attention
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
26
2011 c© M. Schmidt/INT
Backup
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
27
2011 c© M. Schmidt/INT
SNR @ 450 MHz 3d Plot vs. Input Amplitudes
00.2
0.40.6
0.81
0
0.5
130
35
40
45
50
55
60
NormalizedAmplitude @f=2/5f
s
NormalizedAmplitude @f=1/5f
s
SN
R [dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
28
2011 c© M. Schmidt/INT
SNR @ 900 MHz 3d Plot vs. Input Amplitudes
00.2
0.40.6
0.81
0
0.5
130
35
40
45
50
55
60
NormalizedAmplitude @f=2/5f
s
NormalizedAmplitude @f=1/5f
s
SN
R [dB
]
University of StuttgartInstitute of Electrical and Optical Communications EngineeringProf. Dr.-Ing. Manfred Berroth
29
2011 c© M. Schmidt/INT