Frequency Modulation Theory

Foreword

Introduction


1. Propagation — Energy Transfer


1.1 Definition of the Transmission Equivalent


1.2 Propagation of the Carrier Wave in Free Space — Calculation of the Transmission Equivalent Between Aerials


1.3 Propagation in the Atmosphere and Near the Ground


1.4 Atmospheric Absorption


1.5 Atmospheric Refraction


1.6 Fresnel Ellipsoid


1.7 Profile Representation


1.8 Ground Reflections


1.9 Attenuation by a Hill-Crest of the "Knife Edge" Type


1.10 Conclusions Regarding the Installation of Radio Links over an Optical Path


1.11 Tropospheric Propagation Beyond the Horizon

References


2. Distortion and Noise in Frequency Modulation


2.1 Principle of Frequency Modulation


2.2 Spectrum of a Sinusoidally Frequency-Modulated Oscillation


2.3 Non-Linear Distortions in Frequency Modulation


2.4 Analysis of Amplitude Distortion


2.5 Analysis of Phase Distortion


2.6 Application of General Network Laws for the Evaluation of Phase Distortion in Amplifiers


2.7 Phase Distortion in an Amplifier Consisting of a Series of Triplets


2.8 Noise in Frequency Modulation


2.9 Method of Direct Calculation of Non-Linear Distortion in Frequency Modulation

References


3. Propagation Distortion


3.1 Signal Expressed by the Fourier Integral


3.2 Localization of the Information by the Stationary Phase Principle


3.3 Phase Velocity and Group Velocity of a Travelling Wave


3.4 Wave Propagation Along a Double Path


3.5 Distortion in Frequency Modulation for the Double Path Case


3.6 Transmission on a Mismatched Feeder


3.7 Frequency Modulation Distortion in a Mismatched Feeder


3.8 Direct Calculation of Frequency Modulation Distortion over a Double Path

References


4. Transmission of the Overall Information


4.1 General


4.2 Frequency Distribution in Carrier Current Multiplex


4.3 Problem of Levels in Carrier Current Multiplex


4.4 Application of Multiplex Signals to Frequency Modulation Radio Equipment


4.5 Formulae Related to Thermal Noise


4.6 Overall Cross-Talk Power in Amplitude Modulation


4.7 Intermodulation Distribution in the Base-Band


4.8 Combination of Intermodulation in the Various Elements of a Microwave Link


4.9 The Muhiplex Signal Considered as a Stationary Random Function—Application to the Calculation of the Intermodulation Spectrum


4.10 Intermodulation in Frequency Modulation Equipment


4.11 Propagation Cross-Talk


4.12 Transmission Conditions for Television Signals


4.13 Principal Technical Problems Raised by the Transmission of Television on Microwave Links

References


5. Equipment


5.1 Design of Radio Link Equipment


5.2 Structure of Microwave Links


5.3 Highly Linear Modulation and Demodulation—General Remarks


5.4 Frequency Modulation of the U.H.F. Band


5.5 Frequency Modulators Operating in the "Intermediate Frequency" Band


5.6 Demodulation


5.7 Amplification Technique—General Remarks


5.8 Noise Figure


5.9 Amplifier Pass-Band and Gain


5.10 Impedance Breaks Between Elements of an Amplifier Chain


5.11 Phase Distortion Correction—Group Propagation Time Equalizers


5.12 Frequency Changing—Mixers


5.13 Frequency Stabilization


5.14 Filters for Hyper-Frequencies


5.15 Aerials


5.16 Ferrite Unidirectional Attenuator (Isolator)


5.17 Measurements

References

Notations

Abbreviations

Index