The focus is given on millimeter/micro wave signal generation based on external modulators. The working principle and modulation characteristics of Mach-Zehnder modulators (MZM) are introduced. Literature review is presented on generating millimeter/micro wave signals with 4-, 6-, and 8-times frequency multiplication based on cascaded MZMs or dual-parallel MZMs (DPMZMs). A novel scheme to optically generate a microwave signal with 10-times frequency multiplication is proposed. The proposed scheme is based on two DPMZMs and a polarizer. It does not require electrical phase shifters with specified degrees, which are needed in the conventional 10 times frequency multiplication structure. Simulation is conducted to evaluate the performance of the proposed scheme. When a 1 GHz RF drive signal turns into two DPMZMs with a 35 dB extinction ratio, the proposed 10 times frequency multiplier with an optical sideband suppression ratio (OSSR) higher than 25 dB can be obtained. A 10 GHz mm-wave with an RF spurious suppression ratio (RFSSR) over 16 dB is generated. A frequency quadrupling scheme based on a DPMZM is experimentally demonstrated. With a 3 GHz RF drive signal, an OSSR higher than 8 dB is obtained and a 12 GHz mm-wave is generated with an RFSSR over 11 dB.
Inhaltsverzeichnis (Table of Contents)
- Chapter 1 Introduction
- 1.1 Microwave photonics
- 1.1.1 Background
- 1.1.2 Microwave photonic link
- 1.2 Advantages
- 1.3 Research fields and applications
- 1.4 Conclusion
- Chapter 2 Optical generation of micro/millimeter wave technology
- 2.1 Background
- 2.2 Optical Heterodyne
- 2.2.1 Optical Injection Locking
- 2.2.2 Optical Phase Lock Loop
- 2.2.3 Optical Injection Phase—Locked Loop
- 2.3 Opto-electronic Oscillator
- 2.4 External modulation method
- Chapter 3 Optical external modulator
- 3.1 Electro-optic effect
- 3.2 Mach-Zehender Modulator
- 3.3 Dual Drive MZM
- 3.4 Modulation theory
- 3.4.1 Double-sideband (DSB) modulation
- 3.4.2 Single-sideband (SSB) modulation
- 3.4.3 Optical carrier suppressed double-sideband (OCS-DSB) modulation
- 3.4.4 Odd-order optical sideband modulation
- 3.4.5 Even-order optical sideband modulation
- 3.4.6 Linear modulation
- 3.5 Conclusion
- Chapter 4 Literature review
- 4.1 Introduction
- 4.2 Microwave generation with frequency doubled based on one biased MZM
- 4.2.1 System structure and principle
- 4.2.2 Simulation
- 4.2.3 Experiment and conclusion
- 4.3 Microwave signal generation based on two cascaded MZMs
- 4.3.1 Frequency quadrupling scheme
- 4.3.2 Frequency sextupling scheme
- 4.3.3 Frequency octupling scheme
- 4.3.4 Summary
- 4.4 Microwave signal generation based on a Dual-parallel Mach-Zehnder Modulator
- 4.4.1 System structure and principle
- 4.4.2 Frequency quadrupling scheme
- 4.4.3 Frequency sextupling scheme
- 4.4.4 Frequency octupling scheme
- 4.4.5 Frequency 12-tupler scheme
- 4.4.6 Conclusion
- 4.5 Frequency octupling scheme based on two parallel DPMZMs
- 4.5.1 The system structure and principle
- 4.5.2 Simulation
- 4.5.3 Conclusion
- 4.6 Frequency 10-tupling scheme
- 4.6.1 Frequency 10-tupling based on cascaded MZMs
- 4.6.2 Frequency 10-tupling based on DPMZM and SBS
- 4.6.3 Conclusion
- Chapter 5 Simulation for the MZM or DPMZM in VPI
- 5.1 Simulation for MZM
- 5.1.1 Even-order optical sidebands
- 5.1.2 Odd-order optical sidebands modulation
- 5.1.3 Linear optical sidebands
- 5.2 How to suppress the first-order optical sidebands
- 5.2.1 Modulation theory
- 5.2.2 Simulation
- 5.3 Photonic frequency multiplication microwave generation based on DPMZM
- 5.3.1 Modulation theory
- 5.3.2 Simulation analysis
- 5.4 Generation of single sidebands based on one MZM and one PM without a coupler
- 5.4.1 Basic principle
- 5.4.2 Simulation
- 5.4.3 Conclusion
- Chapter 6 Microwave signal generation based on two parallel DP-MZMs
- 6.1 A scheme for generating frequency 8-tupling microwave based on two DPMZMs
- 6.1.1 Basic principle
- 6.1.2 Simulation for Frequency 8-tupling microwave generation
- 6.2 Frequency 12-tupling microwave generation scheme based on two parallel DP-MZMs
- 6.2.1 Basic principle
- 6.2.2 Simulation for Frequency 12-tupling microwave generation
- Chapter 7 New schemes for frequency 10-tupling microwave generation
- 7.1 Frequency 10-tupling microwave generation scheme based on one DP-MZM.
- 7.1.1 Basic principle
- 7.1.2 Simulation for Frequency 10-tupling microwave generation
- 7.2 Frequency 10-tupling microwave generation scheme based on two parallel DP-MZMs.
- 7.2.1 Basic principle
- 7.2.2 Simulation for Frequency 10-tupling microwave generation
- 7.3 Conclusion
- Chapter 8 Experiment
- 8.1 Validating modulation index
- 8.1.1 Principle
- 8.1.2 Simulations and experimental results
- 8.1.3 Conclusion
- 8.2 Generation of frequency-quadrupled microwave signals based on one DPMZM
- 8.2.1 Principle
- 8.2.2 Simulation structure
- 8.2.3 Experimental results
- 8.2.4 Conclusion
Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)
This thesis aims to explore novel schemes for generating high-frequency, high-quality microwave signals using optical methods, specifically focusing on frequency multiplication techniques based on external modulators. The work investigates the limitations of traditional electronic methods and highlights the advantages of microwave photonics.
- Optical generation of millimeter/microwave signals
- Frequency multiplication using Mach-Zehnder Modulators (MZMs) and Dual-Parallel MZMs (DPMZMs)
- Comparison of different modulation techniques (DSB, SSB, OCS-DSB)
- Simulation and experimental validation of proposed schemes
- Exploration of novel architectures for higher frequency multiplication factors (e.g., 10-times)
Zusammenfassung der Kapitel (Chapter Summaries)
Chapter 1 Introduction: This chapter introduces the concept of microwave photonics, highlighting its advantages over traditional electronic methods for generating high-frequency microwave signals. It discusses the background of microwave photonics, the structure and advantages of microwave photonic links, the research fields and applications of microwave photonics, and concludes with the main objective of the thesis: exploring optical methods for generating high-frequency, high-quality microwave signals.
Chapter 2 Optical generation of micro/millimeter wave technology: This chapter provides a background on the importance of high-frequency millimeter/microwave generation technology. It compares traditional methods with microwave photonic approaches and details the advantages of using microwave photonics. Different methods for generating microwave signals are introduced, including direct modulation, optical heterodyne, optoelectronic oscillators, and the external modulation method, which is the focus of the subsequent chapters.
Chapter 3 Optical external modulator: This chapter focuses on the optical external modulator, specifically the Mach-Zehnder Modulator (MZM). It explains the electro-optic effect and details the working principle and characteristics of MZMs, including single-drive, dual-drive, and dual-parallel MZMs. Different modulation theories and their corresponding parameter settings are analyzed, including double-sideband (DSB), single-sideband (SSB), optical carrier suppressed double-sideband (OCS-DSB), odd-order, and even-order sideband modulation, and linear modulation. Simulation results using OptiSystem software are presented and discussed to illustrate different modulation modes and spectrum characteristics.
Chapter 4 Literature review: This chapter reviews existing literature on microwave signal generation using Mach-Zehnder modulators. It examines various frequency multiplication schemes (frequency doubling, quadrupling, sextupling, and octupling) based on single MZMs, cascaded MZMs, and Dual-Parallel MZMs (DPMZMs). Each scheme's structure, principle, and limitations are discussed, alongside simulation results obtained using OptiSystem software. The chapter also explores frequency 10-tupling schemes from the literature.
Chapter 5 Simulation for the MZM or DPMZM in VPI: This chapter details simulations performed using VPI software to analyze the characteristics of MZMs and DPMZMs. It focuses on generating even-order and odd-order optical sidebands and linear optical sidebands by varying the bias voltage and modulation index. The chapter explores methods for suppressing specific sidebands to enhance the quality of generated microwave signals. The simulation results using VPI are compared with those from OptiSystem. It also proposes a new scheme for generating single-sideband signals using a single MZM and phase modulator.
Chapter 6 Microwave signal generation based on two parallel DP-MZMs: This chapter presents a novel scheme for generating frequency 8-tupling and 12-tupling microwave signals using two parallel DPMZMs and a polarizer. The basic principles are discussed, and VPI simulation results are provided to demonstrate the feasibility of generating high-quality microwave signals with high RFSSR using this architecture. The chapter elaborates on the theoretical analysis and simulation results, showing how specific parameter adjustments lead to the desired frequency multiplication.
Chapter 7 New schemes for frequency 10-tupling microwave generation: This chapter proposes two new schemes for 10-times frequency multiplication: one using a single DPMZM and the other using two parallel DPMZMs. The principles behind these schemes are explained, and VPI simulation results are presented and analyzed, comparing the performance of the two schemes. The chapter concludes by highlighting the advantages of the proposed architectures, such as wide bandwidth, all-optical approach, and high RFSSR.
Chapter 8 Experiment: This chapter describes two experiments conducted to validate the findings from the previous chapters. The first experiment validates the modulation index using a single MZM, comparing experimental results to VPI simulations. The second experiment demonstrates the generation of a frequency-quadrupled microwave signal using a single DPMZM, comparing the experimental results with VPI and OptiSystem simulations.
Schlüsselwörter (Keywords)
Microwave photonics, millimeter-wave generation, frequency multiplication, Mach-Zehnder modulator (MZM), Dual-Parallel MZM (DPMZM), external modulation, double-sideband (DSB) modulation, single-sideband (SSB) modulation, optical carrier suppressed double-sideband (OCS-DSB) modulation, optical sideband suppression ratio (OSSR), radio frequency spurious suppression ratio (RFSSR), VPI, OptiSystem, simulation, experiment.
Microwave Photonics: Frequency Multiplication using MZMs and DPMZMs - FAQ
What is the main topic of this thesis?
This thesis explores novel schemes for generating high-frequency, high-quality microwave signals using optical methods, specifically focusing on frequency multiplication techniques based on external modulators like Mach-Zehnder Modulators (MZMs) and Dual-Parallel MZMs (DPMZMs).
What are the key advantages of using microwave photonics for microwave signal generation?
The thesis highlights the advantages of microwave photonics over traditional electronic methods for generating high-frequency microwave signals, emphasizing its capabilities in achieving high-frequency, high-quality signals.
What types of modulators are used in this research?
The research primarily utilizes Mach-Zehnder Modulators (MZMs) and Dual-Parallel Mach-Zehnder Modulators (DPMZMs) for frequency multiplication.
What modulation techniques are discussed?
The thesis discusses various modulation techniques, including Double-Sideband (DSB), Single-Sideband (SSB), Optical Carrier Suppressed Double-Sideband (OCS-DSB), odd-order, even-order, and linear modulation. The effects of these techniques on signal quality are analyzed.
What frequency multiplication factors are achieved?
The research explores frequency doubling, quadrupling, sextupling, octupling, and particularly focuses on novel schemes for achieving frequency 10-tupling.
What simulation software is used?
The thesis uses both VPI and OptiSystem software for simulations to analyze the performance of different modulation schemes and to predict the characteristics of the generated microwave signals.
Are there experimental results included?
Yes, the thesis includes experimental results to validate the simulation findings and demonstrate the feasibility of the proposed schemes. Experiments focused on validating modulation index and generating frequency-quadrupled signals.
What are the key findings of the thesis?
The thesis presents novel schemes for efficient frequency multiplication using MZMs and DPMZMs, particularly achieving high-frequency multiplication factors (e.g., 10-times). Simulation and experimental results validate the feasibility and performance of these schemes.
What are the key challenges addressed in this research?
The research addresses challenges related to generating high-quality microwave signals with high frequency multiplication factors, focusing on minimizing unwanted sidebands and optimizing modulation techniques for better signal quality (high OSSR and RFSSR).
How are the results presented?
The results are presented through a detailed explanation of the principles, simulation results from VPI and OptiSystem, and experimental validation. Each chapter provides a summary of its key findings and contributions.
- Quote paper
- Chongjia Huang (Author), 2017, Microwave photonic frequency multiplier with 10 times frequency multiplication, Munich, GRIN Verlag, https://www.grin.com/document/432864
