Contents. Preface. xiii. Part I 1

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2 Contents Preface xiii Part I 1 Chapter 1 Introduction to Frequency-Modulated Continuous-Wave 3 Radar 1.1 Brief History Examples of Use of FMCW Radar Radio Altimeters Level-Measuring Radar Navigational Radar Vehicle Collision Warning Systems Precision Range Meter for Fixed Targets Measurement of Very Small Motions 9 References 9 Chapter 2 Basic Theory of Short-Range FM Radar Principle of Operation and Basic Block Diagram of FM Radar Typical Block Diagram of Short-Range FM Radar System with Separate Transmitting and Receiving Antennas and Nonzero Intermediate Frequency Circuit with Nonzero Intermediate Frequency and Complex Frequency Modulation System with a Single Transmitting-Receiving Antenna Autodyne System with a Single Antenna 16 vii

3 viii Fundamentals of Short-Range FM Radar 2.3 General Expressions for Transmitted, Reflected, and Converted Signals General Relationships for the Converted Signal with Modulation by a Periodic Function General Relations for a Converted Signal with Dual- Frequency Modulation General Relations for a Converted Signal with Modulation by a Modulated Periodic Function Block Diagrams of Ultrasonic SRR and Features of the Converted Signal 25 Chapter 3 Characteristics of the Converted Signal with Different Transmitter Modulations Sinusoidal Modulation Modulation by a Single Sinusoid Dual Sinusoidal Modulation Linear Frequency Modulation Modulation with an Asymmetrical Sawtooth Function Modulation with Non-Isosceles and Symmetrical Sawtooth Functions Discrete Modulation Effects of Transmitter Modulation Nonlinearity on Converted Signal Parameters 45 Chapter 4 Integrated Methods of Converted Signal Processing General Description Effect of Parasitic Amplitude Modulation of the Transmission on Operation of the SRR Receiver General Description Methods of Decreasing PAM Signal Effects on Receiver Operation Stabilization of the Frequency Deviation Frequency Processing of the Converted Signal Range Finding by Counting the Number of Zero Points of the Converted Signal for a Modulation Period Measuring of the Instantaneous Frequency Fixing the Instantaneous Frequency of the Converted Signal Use of the Frequency Deviation of the Converted Signal Applying Dual Sinusoidal Modulation 71

4 Contents ix Single-Antenna Version with Zero Intermediate Frequency Fixing the Frequency Deviation of the Converted Signal Phase Processing of the Converted Signal 81 References 88 Chapter 5 Spectral Methods of Processing the Converted Signal General Description Range Resolution Radar Scan of Range Spectral Processing Using the Parasitic AM Signal Signal Processing on Separate Components of the Converted Signal Spectrum Formation of the Discriminator Characteristic Phase Processing of Separate Components of the Converted Signal Spectrum 113 References 122 Part II 123 Chapter 6 Analysis of Constant Frequency Oscillators Rule for Obtaining the Abbreviated Equations Substantiation of the SAE Method Examples of Deriving the Abbreviated Equations Single-Tuned Oscillator with Fixed Bias Voltage Single-Tuned Oscillator with Automatic Bias General Abbreviated and Characteristic Equations of Anisochronous Oscillators Abbreviated Equations of Anisochronous Oscillators Stationary Modes of the Oscillator General Characteristic Equation of the Anisochronous Oscillator Condition of Self-Excitation of Oscillators with Inertial Active Elements Order of the Characteristic Equation and the Sign of the Factor at the Upper Derivative 149 References 150 Chapter 7 Analysis of FM Systems Using Symbolical Abbreviated Equations Symbolical Abbreviated Equations for Controlled Self- Oscillatory Systems of Any Kind 151

5 x Fundamentals of Short-Range FM Radar 7.2 Method of Symbolical Abbreviated Equations for FM Systems Differential Equations of Some FM Systems Differential Equations of a Parallel Conservative LC Circuit with Variable Capacitance and an Active Two-Pole Differential Equations of a Parallel Dissipative LC Circuit with Variable Capacitance and an Active Two-Pole Abbreviated Differential Equations of Single-Tuned Oscillators with Sinusoidal FM Parasitic Amplitude Modulation in Autodynes for Various Types of Frequency Modulation Sine Wave Frequency Modulation Binary Frequency Modulation Frequency Modulation by an Asymmetrical Sawtooth Frequency Modulation with a Symmetrical Sawtooth 171 References 172 Chapter 8 Output Voltage of a Frequency-Controlled Oscillator Change of Output Voltage for Oscillators Tuned Discretely in Time Parasitic Amplitude Modulation of Oscillations in Ideal Single-Tuned Circuits with Modulation of Their Natural Frequencies Parasitic Amplitude Modulation of Output Voltage in Single-Tuned Oscillators with Frequency Modulation Use of a Varicap as the Frequency Controller 193 References 200 Chapter 9 Nonlinearity and Linearization in Varactor Control of FM Oscillators Nonlinearity of Frequency Dependence of Single-Tuned Oscillators on Control Voltage of the Varactor with Large Frequency Changes Nonlinear Distortions with Frequency Modulation Using Varactors Nonlinear Distortions for Capacitor Coupling of the Varactor to the Oscillator Circuit 210

6 Contents xi Nonlinear Distortions for Autoinductive Coupling of the Varactor to the Oscillator Circuit Nonlinear Distortions in the Case of a Single- Tuned Oscillator Circuit with Allowance for RF Voltage on the Varactor Linearization of Dependence of Oscillator Frequency on Control Voltage Calculation of Diode-Resistive Correction Circuits Decreasing the Nonlinear Distortion of the FM Signal with a Correcting Signal 223 Chapter 10 Theory of the Single-Tuned Transistor Autodyne and Optimization of Its Modes Abbreviated Differential Equations for the Single-Tuned Transistor Autodyne Linearized Differential Equations of Autodynes for Small Reflected Signals Equivalent Circuits of Autodynes for Small Reflected Signals The Form and Spectrum of the Output Signal of a Single-Tuned Transistor Autodyne Form and Spectrum of the High-Frequency Signal from an FM Transistor Autodyne Transfer Factors of an Autodyne on a Voltage and a Current and Mode Optimization Analysis for Low Frequencies for a Particular Transistor The High-Frequency Case Choice of Mode with High Autodyne Sensitivity 247 References 248 Chapter 11 Autodyne Modes of Transistor Oscillators with Strong Interference The Common Properties of Autodyne Modes of the Single-Tuned Synchronized Oscillator Abbreviated Equations for the Synchronized Oscillator Abbreviated Equations in Normalized Parameters Steady-State Synchronous Modes Transients at Synchronism Bifurcational Diagrams of a Transistor 260 Autodyne

7 xii Fundamentals of Short-Range FM Radar 11.2 Transfer Factor of an Autodyne Subject to Synchronous Jamming Bifurcations of Periodic Variations in the Synchronized Autodyne 269 References 273 List of Symbols 275 About the Authors 281 Index 285