Electromechanical transmitters for ELF/VLF radio / Jarred S. Glickstein, Soumyajit Mandal.

Format:

Book

Author/Creator:

Glickstein, Jarred S., author.

Mandal, Soumyajit, author.

Series:

Synthesis lectures on engineering, science, and technology.

Synthesis lectures on engineering, science, and technology

Language:

English

Subjects (All):

Radio--Transmitters and transmission.

Radio.

ELF electromagnetic fields .

VLF radio wave propagation .

Physical Description:

1 online resource (222 pages)

Place of Publication:

Cham, Switzerland : Springer, [2022]

System Details:

Mode of access: World Wide Web.

Summary:

This book describes a new, extremely low frequency (ELF)/ very low frequency (VLF) miniaturized transmitter concept, based on the mechanical motion of permanent magnets or electrets. The authors explain how utilizing the very high energy density of modern ferromagnetic and ferroelectric materials, such "electromechanical transmitters'' can provide much higher field generation efficiency than conventional antennas, thus enabling practical ELF/VLF wireless communications links. The text begins with the fundamental challenges of such links and provides an historical overview of the attempts that have been made to address these challenges. It then focuses on the design and implementation of practical electromechanical ELF/VLF transmitters, which is an interdisciplinary subject that spans multiple research areas including electromagnetics, power electronics, control systems, and mechanical design. The authors also describe how such transmitters can be combined with receivers and signal processing algorithms to realize complete ELF/VLF links in challenging environments.

Contents:

Intro

Foreword

References

Preface

Acknowledgements

Contents

Acronyms

1 Introduction

1.1 Overview of the Book

1.2 Motivation: Radio Silence in Conductive Media

1.3 Properties of ELF Communications

2 Historical Overview

2.1 Development of ELF/VLF Communication Systems

2.1.1 ELF/VLF Communication with Electrical Antennas

2.1.2 Underwater Communication Modes

2.1.3 Cave Communication

2.2 Development of Electromechanical ELF/VLF Transmitters

3 Electromagnetic Modeling

3.1 Field Generation

3.1.1 Rotating Magnetic Dipole

3.1.2 Rotating Electric Dipole

3.1.3 Effect of Ground Planes

3.1.4 Comparison Between Magnetic and Electric Dipoles

3.2 Power Consumption

3.2.1 Shape of the Dipole

3.2.2 Distributed Transmitters

3.2.3 Dynamic Stability

3.2.4 Interactions Between Rotating Dipoles

4 Design of ELF Communications Links

4.1 Natural and Artificial Activity in the ELF Channel

4.1.1 Atmospheric Effects

4.1.2 Schumann Resonance

4.1.3 Animal Response

4.2 Characterization of the ELF Channel

4.3 System Design

4.3.1 Data Modulation

4.3.2 Minimizing Power Consumption

4.3.3 Simulation Results

4.3.4 Differential Coding

4.3.5 Bit Error Rate (BER) Analysis

4.3.6 Data Encoding

5 Open-Loop Prototype

5.1 Prototype Experimental Setup

5.2 Prototype Experimental Setup: The Completed Assembly

5.2.1 Transmitter Design

5.2.2 Receiver Design

5.3 Experimental Results

5.3.1 Field Strength Versus Distance

5.3.2 Wireless NLOS Data Transmission

5.3.3 Sample Data Encoding

5.3.4 Practical Message Transmission

5.3.5 Bit Error Rate (BER) Analysis of the Prototype

5.3.6 Power and Energy Consumption with CP-FSK and CF-FSK

5.3.7 Effects of Non-random Data

6 Design of a Closed-Loop Transmitter

6.1 Main Design Goals.

6.1.1 Bandwidth Selection

6.2 A Model for the Mechanical System

6.2.1 The Fundamental Model

6.2.2 Constraining the System and Optimizing the Model

6.2.3 Constraining the Communication Domain

6.2.4 Constraining the Mechanical Domain

6.2.5 The Gasoline Engine Analogy to the Electric Motor

6.2.6 Summary of Constraints for Optimization

6.3 Torque Required to Drive Assembly

6.3.1 Torque Due to Bearing Power Loss

6.3.2 Modulation Torque

6.3.3 Static Torque Due to Drag

6.3.4 Summary of Torque Requirements

6.4 The Optimum Magnet

6.4.1 Sizing the Magnet from Available Torque

6.4.2 Real Size of the Magnet, A Boundary Value Problem

6.5 Modular Transmitter Design

6.5.1 Resolving the Field Generation Limit

6.5.2 BER Analysis of Optimum Magnet Design

7 Implementation of the Closed-Loop Transmitter

7.1 Mechanical Design

7.1.1 Selecting a Motor

7.1.2 Air Supply

7.1.3 Permanent Magnet

7.1.4 Shaft Coupling

7.1.5 Computer-Aided Design of the Mechanical Assembly

7.1.6 Critical Speed of the Rotating Assembly

7.2 A Three-Phase Motor Driver

7.2.1 Drive Type and Requirements

7.2.2 Motor Controller Board

7.2.3 Revised Motor Controller Board

7.3 Machining and Assembly

7.3.1 Alternative Methods for Centering the Magnet

7.3.2 Returning to the Bigger Picture

7.3.3 ``Fit by Feel''

8 Transmitter Control System

8.1 System Overview

8.1.1 Hardware Test Bench

8.1.2 A Model for the Plant

8.1.3 Remarks

8.2 Digital Controller

8.2.1 Driving the Motor

8.2.2 Feedback and Speed Measurement

8.2.3 Data Collection

8.2.4 A Model for the Controller

8.3 Software Interface

8.3.1 Datatype Organization

8.3.2 Message Encoding

8.3.3 Sendmail: Real-Time Data Modulation

8.4 Experimental Performance Characteristics

8.4.1 Testing the Drive.

8.4.2 Tuning the Controller

8.4.3 System Response and Stability Margins

8.4.4 Modulation Energy Explained

9 ELF Receiver Design

9.1 Overview of the Receiver

9.2 Background

9.2.1 On Detection and Measurement Sensitivity of Magnetic Fields

9.2.2 Proposed Detector Design

9.2.3 Related Work

9.3 Receiver Design

9.3.1 Magnetic Field Sensor

9.3.2 Low-Noise Front-End

9.3.3 Measured Characteristics

9.3.4 3-Axis Antenna Calibration

9.4 Portable Field Unit

9.5 Performance and Concluding Remarks

10 A Complete ELF Communication System

10.1 Field Setup: Transmitter

10.2 Results of Line of Sight Testing

10.2.1 Single Tone Transmission

10.2.2 Established CP-FSK Data Link

10.2.3 Maximum Link Distance

10.3 Cave Deployment

11 Conclusions and Future Work

11.1 Conclusions

11.1.1 Introduction to the AMEBA Concept

11.1.2 Implementation of an Open-Loop AMEBA Prototype

11.1.3 Design of a Closed-Loop AMEBA Transmitter

11.1.4 Implementation of the Closed-Loop Transmitter

11.1.5 Transmitter Control System

11.1.6 Design and Implementation of an ELF Receiver

11.1.7 A Complete ELF Communication System

11.2 Future Work

11.2.1 Mechanical ELF Transmitters

11.2.2 ELF Receivers

A Spectral Content of Modulated PWM Signals

A.1 Time-Domain Definition

A.2 Frequency Domain

A.3 Direct Approach to Finding upper P left parenthesis t right parenthesisP(t)

Appendix Glossary

Index.

Notes:

Includes bibliographical references and index.

Description based on print version record.

Other Format:

Print version: Glickstein, Jarred S. Electromechanical Transmitters for ELF/VLF Radio

ISBN:

3-031-15123-2