Post on 20-Dec-2015
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R I TRochester Institute of Technology
A New High-Efficiency, Linear Power Amplification Design Technique Derived from
Nonlinear Dynamical Systems
Dr. Chance M. Glenn, Sr.
Associate Professor – Department of Electrical Computer and Telecommunications Engineering Technology
Director – The Laboratory for Wireless Networks and Advanced Communications Technology
Rochester, New York USA
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R I TRochester Institute of Technology
Overview
•This talk describes the basis and implementation of a new concept in power amplifier design.
•This work represents a collaborative effort between the Laboratory for Wireless Networks and Advanced Communications Technology at RIT, and Syncrodyne Systems Corporation.
•The ongoing research effort has also been supported by DARPA, ARO, and MDA
•The goal is the commercial application of this technology in various forms of wireless telecommunications.
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R I TRochester Institute of Technology
Syncrodyne Power AmpBlock Diagram
Chaotic Oscillator
DC Power
Adaptive Power Control&
Output Stabilization
Coupling Control
Input x(t) Output y(t)
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R I TRochester Institute of Technology
Chaotic Dynamics
• The heart of the Syncrodyne Power Amplifier is the chaotic oscillator
• Chaos is a type of behavior that occurs in nonlinear systems.
• While chaos tends to elude specific definition, there are properties that define its behavior:
1. Broad-band frequency spectra2. Sensitivity to small changes3. Tendency towards synchronization4. Capable of efficient operation (nonlinearity)
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Chaotic Dynamics
1 evc ei
whereVe
Vc
R
Re
L
Ce
C
+
Vee
Q
+
Vcc
Circuit diagram:
cLec
e
EEeL
ee
LLcCCL
iidt
dvC
dt
dvC
R
Vvi
dt
dvC
iRRvVdt
diL
• A typical chaotic oscillator is the Colpitts system.
• The Colpitts circuit is a typical circuit topology used in the engineering design of oscillators.
Equations of motion:
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Chaotic Dynamics
State-space plot:
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The term Syncrodyne derives from the concept of amplification using synchronous dynamics. Dynamically matched devices are used which lock to a signal of similar dynamics.
The green (applied) and blue (output) signals in this schematic representation come together (synchronize) and the error (red) goes to zero rapidly when the input is coupled.
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Syncrodyne Amplification
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Adaptive Nature of Synchronization
•We first reported that a chaotic system was adaptable, or conformed to, non-chaotic waveforms.
•That is, a chaotic system, properly coupled, will take on the nature of an arbitrary waveform, depending on some conditions.
•This realization was critical to the implementation of this technique on typical information bearing signal formats like GSM and CDMA.
•We first showed this adaptive conformity using phase modulated sinusoidal waveforms coupled to a Colpitts oscillator operating in the chaotic regime.
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0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0 6.0
-80
-60
-40
-20
0
-100
20
freq, GHz
dB(F
Vin
)
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0 6.0
-80
-60
-40
-20
0
-100
20
freq, GHz
dB(F
Vo)
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0 6.0
-100
-80
-60
-40
-20
0
-120
20
freq, GHz
dB
(FV
o)
CouplingSpectral content of the free-runningchaotic oscillator.
Spectral content of the generated GSM signal.
Spectral content of the amplified GSMwaveform using the Syncrodyne Power Amplifier Series-3 prototype simulation.
Syncrodyne AmplificationR I TRochester Institute of Technology
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R I TRochester Institute of Technology
Syncrodyne Amplification
The extent and effectiveness of Synchronization depends on the factors below: dc bias voltages of the source signal and the chaotic signal (Vsdc and Vcdc)
peak to peak voltage range of the two signals (Vsr and Vcr) fundamental frequencies of the two signals Value of coupling impedance in the coupling circuit
The factors mentioned above need to be properly matched to obtain maximum amplification of the source signal.
Increase in the extent of coupling would increase the gain and the efficiency of the signal produced.
1.284 1.286 1.288 1.290 1.292 1.294 1.296 1.298 1.300 1.302 1.3041.282 1.306
-1
0
1
2
-2
3
time, usec
Vin
, V
1.068 1.070 1.072 1.074 1.076 1.078 1.080 1.082 1.084 1.0861.066 1.088
-1
0
1
2
3
-2
4
time, usec
Vo,
VVsdc VcdcVsr
Vcr
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The power amplifier system comprises of the following components: The dc power source (5 volts dc) – V_DC The chaotic oscillator The coupling network The modulated input source (GSM modulation at 800 MHz) The load impedance
Vin
VoVdc
modulatorX3
Modulated Source
I_ProbeIinSPA-S3-C2-BJ T-CPL
X2
CouplingNetwork
21
SPA-S3-C2-BJ T-OSCX1
sig outsig in
CODC in
2
1
3I_ProbeIdc I_Probe
Io
RRloadR=50 OhmV_DC
SRC1Vdc=5.0 V
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© The Laboratory for Wireless Networks and Advanced Communications Technology
ADS Simulation Diagram
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The circuit has three ports, the functions are as below
Port1 – dc supply (input) Port2 – Amplified signal (output) Port3 – Modulated signal (input)
The other components are varied to obtain the desired output.
Sample values are shown in the figure.
CC4C=C4o pF
CC5C=C5o pFL
L1
R=.707L=L1o nH
CC2C=C2o pF
CC1C=C1o pFR
R1R=R1o Ohm
RR2R=R2o Ohm
CC3C=C3o pF
RR4R=R4o Ohm
RR3R=R3o Ohm
CCLC=0.158 pF
RR5R=0 OhmPort
P3Num=3
PortP2Num=2
PortP1Num=1
pb_nec_NE68130_19921215Q3
P1
P3
P2
VAROscillator
L1o=10C5o=472C4o=156C3o=36C2o=4C1o=7.89R4o=10R3o=15466R2o=290R1o=5400
EqnVar
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ADS Simulation Diagram
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The system SPA-S3-C2-BJT-SYS2 was simulated and the results obtained are as shown below. Other such circuits were simulated and the results are have been tabulated in an excel sheet.
PAE (%) 52.301
Gain (dB) 18.129
Vo_avg (V) 0.654
Vo_range (V) 2.126
Pdc (W) 0.066
Po_rf (W) 0.130
Pin_rf (W) 0.002
Pin_rf_dBm 1.895
Po_rf_dBm 20.040
FVoFund (dB) 4.670
Fdown (dB) 28.143
FVoHarm (dB) -23.473
Lyapunov Exp 1.84370.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0 6.0
-100
-80
-60
-40
-20
0
-120
20
freq, GHz
dB
(FV
o)
Synchronized output signal
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50.0 6.0
-80
-60
-40
-20
0
-100
20
freq, GHz
dB(F
Vo)
R I TRochester Institute of Technology
Results
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R I TRochester Institute of Technology
Conclusions
© The Laboratory for Wireless Networks and Advanced Communications Technology
•We’ve demonstrated Syncrodyne Power Amplification for GSM waveforms with PAE greater than 50% and gain approaching 20-dB
•We are implementing new techniques that should allow us to push the performance levels higher.
•The property of chaotic oscillators to adaptively conform to different waveform types is a key to this concept.
•We are able to achieve linear power amplification utilizing a nonlinear device, thus benefiting from the high efficiency capable in nonlinear operation.
•We intend to explore the benefit of this amplification concept in other technology settings.
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R I TRochester Institute of Technology
The Laboratory for Wireless Networks and Advanced Communications Technology
Goals
•Push the performance to PAE > 70%, gain > 30-dB
•Implement Series-3 design in hardware
•Design a SPA-S3 chip to meet commercial performance criteria
•Develop commercially viable testbed for performance evaluation
•Cultivate strategic partnerships for technology adoption.
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R I TRochester Institute of Technology
The Laboratory for Wireless Networks and Advanced Communications Technology
References
[1] E. Ott, C. Grebogi, J. A. Yorke, Phys. Rev. Lett. 64, 1196 (1990).[2] S. Hayes, C. Grebogi, E. Ott, Phys. Rev. Lett. 70, 3031 (1993).[3] H. Dedieu, M.P. Kennedy, and M. Hasler, “Chaos shift keying; Modulation and demodulation of a chaotic carrier using self-synchronizing Chua’s circuit,” IEEE Transactions on Circuits and Systems I, vol. 40, pp. 634-642, 1993.[4] C. M. Glenn, S. Hayes, Weak Signal Detection by Small-Perturbation Control of Chaotic Orbits, 1996 IEEE-MTT Symposium Digest (June 1996).[5] L. M. Pecora and T. L. Carroll, Synchronization in Chaotic Systems, Phys. Rev. Lett. 64, 821 (1990).[6] C. M. Glenn, Synthesis of a Fully-Integrated Digital Signal Source for Communications from Chaotic Dynamics-based Oscillations, Doctoral Dissertation, The Johns Hopkins University, January 2003.[7] C. M. Glenn, High-Gain, High-Efficiency Power Amplification for PCS, International Symposium on Advanced Radio Technology Digest, March 2003.[8] S. Cicarelli, Development of a Digital Wireless Communication System for Security Sensor Applications, Defense Nuclear Agency (Jan 1998)[9] Francis Moon, Chaotic Vibrations, Wiley & Sons, New York, 1987.[10] Edward Ott, Chaos in Dynamical Systems, Cambridge Univ. Press, Canada, 1993.