Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

122 Pages·2009·1.79 MB·English

by  Martin Tijmes

University of Twente
Department of Electrical Engineering
Telecommunication Engineering Group
Simulation of a ring resonator-based
optical beamformer system
for phased array receive antennas
by
Martin Tijmes
Master thesis
Executed from July 2008 to April 2009
Supervisor: prof.dr.ir.ing. F.B.J. Leferink
Advisors: dr.ir. A. Meijerink
dr.ir. C.G.H. Roeloffzen
dr.ir. M.J. Bentum
M. Burla, MSc

Summary
This thesis describes the development of a simulator tool that can be used in the field
of RF photonics. The development has been performed on the basis of a broadband,
continuously tunable ring resonator-based optical beamformer system for phased array
receive antennas. The application that is considered in this thesis is airborne satellite
reception of digital television.
An extensive description of the satellite receiver system is given, in which all the
input-output relations of the individual components in the system are considered. It
is shown that LabVIEW provides a good simulation environment for the application
that is considered, which enables the specification of a suitable signal representation
for both the electrical and optical domain. The simulator tool employs a fixed sample
rate to circumvent the necessity for the laborious operations of up and downsampling.
Based on the discrete-time representation that is introduced, the models are imple-
mented in LabVIEW. The simulation model comprises a dynamical implementation of
the optical beamforming network (OBFN), such that beamforming can be performed
for any number of antenna elements (AEs). The settings that are required for the delay
elements in the OBFN are automatically generated, based on the time delay difference
between individual AEs. The satellite signals and sky noise are modeled as well, to be
able to use a realistic context to test the system and do performance evaluations.
Themodelsoftheindividualcomponentshavebeentestedtomatchtheirtheoretical
responses. It is recommended to verify a full system simulation with theory, and later
on compare with measurements.
Thescalabilityofthemodelhasbeeninvestigatedbydeterminingthecomputational
complexity relations of the most critical blocks. It was shown that a simulation with
more than 2,000 AEs, is likely to be performed within ten minutes.
The developed simulator tool appears suitable for applications in RF photonics in
general, and can be used in continued work on optical beamforming. The performance
of the beamformer is highly dependent on the calculated ring settings for the OBFN.
Therefore, the simulated OBFNs are limited insofar that the required settings must be
able to be determined.
Several recommendations are given to illustrate the usability of the simulator tool,
and remarks are given on the extendability and increment of efficiency.
iii

Contents
Summary iii
List of abbreviations ix
1 Introduction 1
1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Optical beamforming for phased array antennas . . . . . . . . . . . . . 2
1.2.1 Phased array receive antenna . . . . . . . . . . . . . . . . . . . 3
1.2.2 Optical beamformer . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2.3 Previous work on optical beamforming . . . . . . . . . . . . . . 4
1.3 The benefits of simulation . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Assignment goal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.5 Report outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 System overview 9
2.1 Satellite signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Phased array antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 Low-noise block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 E/O conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4.1 Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4.2 Mach-Zehnder modulator (MZM) . . . . . . . . . . . . . . . . . 13
2.5 Optical beamforming network . . . . . . . . . . . . . . . . . . . . . . . 15
2.5.1 Optical ring resonators . . . . . . . . . . . . . . . . . . . . . . . 15
2.5.2 Network structure . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.6 Optical sideband filter . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.7 O/E conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.8 Receiver front-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.9 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3 Simulation environment and signal representation 23
3.1 Choice of the simulation software environment . . . . . . . . . . . . . . 23
v
vi Contents
3.1.1 General requirements . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1.2 General purpose versus dedicated software . . . . . . . . . . . . 25
3.2 Signal representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.2.1 Continuous-time bandpass representation . . . . . . . . . . . . . 27
3.2.2 Discrete-time representation . . . . . . . . . . . . . . . . . . . . 28
3.2.3 Sampling rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4 Modeling the optical system components 35
4.1 Optical ring resonators . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.1.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 36
4.1.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 38
4.2 Optical beamforming network . . . . . . . . . . . . . . . . . . . . . . . 39
4.2.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 39
4.2.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 40
4.3 Optical sideband filter . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.3.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 42
4.3.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 43
4.4 Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.4.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 44
4.4.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 45
4.5 Mach-Zehnder modulator . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.5.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 45
4.5.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 46
4.6 Balanced detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.6.1 Modeling components . . . . . . . . . . . . . . . . . . . . . . . 47
4.6.2 Simulation model and results . . . . . . . . . . . . . . . . . . . 48
4.7 Noise in the optical beamformer . . . . . . . . . . . . . . . . . . . . . . 48
4.7.1 Dark current . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.7.2 Shot noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.7.3 Thermal noise in the photodiode . . . . . . . . . . . . . . . . . 51
4.7.4 Thermal noise in the transimpedance amplifier (TIA) . . . . . . 52
4.7.5 Thermal noise in the MZM . . . . . . . . . . . . . . . . . . . . . 54
4.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5 Defining a context for the optical beamformer 57
5.1 Signal reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.1.1 Definition of the satellite signal . . . . . . . . . . . . . . . . . . 57
5.1.2 DVB-S reception by the antenna elements . . . . . . . . . . . . 59
5.1.3 Downconversion by the LNBs . . . . . . . . . . . . . . . . . . . 61
Contents vii
5.1.4 Noise generated by the AEs and the LNBs . . . . . . . . . . . . 61
5.1.5 Implementation in LabVIEW . . . . . . . . . . . . . . . . . . . 62
5.2 Noise reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2.1 Noise picked up by the AEs . . . . . . . . . . . . . . . . . . . . 64
5.2.2 Coherent noise sources . . . . . . . . . . . . . . . . . . . . . . . 65
5.2.3 Sky noise model in LabVIEW . . . . . . . . . . . . . . . . . . . 66
5.2.4 Combining the generation of the satellite signal with sky noise
generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.3 Decoding a selected channel . . . . . . . . . . . . . . . . . . . . . . . . 69
5.3.1 Implementation in LabVIEW . . . . . . . . . . . . . . . . . . . 70
5.4 System simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6 Computational complexity 75
6.1 Determining the complexity of the model . . . . . . . . . . . . . . . . . 75
6.1.1 Specifying the complexity . . . . . . . . . . . . . . . . . . . . . 75
6.1.2 Critical blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
6.1.3 Extrapolation of the complexity relations . . . . . . . . . . . . . 78
6.2 Indication of the required computational time . . . . . . . . . . . . . . 79
6.3 Possible optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.4 Increase in complexity for more advanced models . . . . . . . . . . . . 81
6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
7 Conclusions and recommendations 85
7.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
References 93
A OBFN structure 95
A.1 Defining the OBFN structure . . . . . . . . . . . . . . . . . . . . . . . 95
A.2 Retrieving the ORR settings . . . . . . . . . . . . . . . . . . . . . . . . 97
B Power spectral density in the discrete time domain 99
C Simulator documentation 103
C.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
C.2 User interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
C.2.1 Generate message . . . . . . . . . . . . . . . . . . . . . . . . . . 105
C.2.2 QPSK modulation . . . . . . . . . . . . . . . . . . . . . . . . . 105
C.2.3 Signal reception . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
viii Contents
C.2.4 Sky noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
C.2.5 MZM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
C.2.6 OBFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
C.2.7 OSBF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
C.2.8 Balanced detection . . . . . . . . . . . . . . . . . . . . . . . . . 107
C.2.9 Bandpass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
C.2.10 Demodulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
C.3 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
List of abbreviations
AE antenna element
BER bit error rate
BPF bandpass filter
CATV cable TV
CMBR cosmic microwave background radiation
CMOS complementary metal-oxide-semiconductor
CNR carrier-to-noise ratio
DC directional coupler
DSB double-sideband
DSB-SC double-sideband suppressed-carrier
DVB digital video broadcasting
DVB-S DVB-satellite
DVB-S2 DVB-satellite version 2
EMI electromagnetic interference
ETSI European Telecommunications Standards Institute
FSR free spectral range
IF intermediate frequency
ISI inter-symbol interference
LNA low-noise amplifier
LNB low-noise block
ix
x List of abbreviations
LO local oscillator
LPF low-pass filter
MEMPHIS Merging Electronics and Micro&nano PHotonics in Integrated Systems
MPEG Moving Pictures Expert Group
MZI Mach-Zehnder interferometer
MZM Mach-Zehnder modulator
OBFN optical beamforming network
OSBF optical sideband filter
ORR optical ring resonator
PAA phased array antenna
PCB printed circuit board
PSD power spectral density
PSK phase-shift keying
QPSK quadrature phase-shift keying
RAM random access memory
RIN relative intensity noise
RF radio-frequency
RoF radio-over-fiber
SANDRA Seamless Aeronautical Networking through integration of Data links,
Radios, and Antennas
SMART SMart Antenna systems for Radio Transceivers
SNR signal-to-noise ratio
SSB single-sideband
SSB-SC single-sideband suppressed-carrier
RS Reed-Solomon
RTT roundtrip time