Reception of Weak Radio Signals from Space

Comprehensive resource on the dynamically developing issue of radio communication over long distances, especially in outer space Reception of Weak Radio Signals from Space explores all aspects of detecting and making sense of extremely weak radio frequency (RF) signals, especially those emanating from space. The subject matter ranges from general physics fundamentals to highly specialized issues of design and optimization of microwave antennas, low-noise amplifiers, receivers, transmitters, and frequency synthesizers with very specific characteristics. Special consideration is paid to the advanced technique of radio linking by reflection of signals from the lunar surface, where, using modern software for digital communication, it is possible to realize links with signals ten or more decibels weaker compared to analogue modes. Each chapter briefly summarizes the theory and applicable relationships and complements the discussed topic with descriptions of specific solutions for individual parts of the communication system. Detailed annotated examples of calculations and implementations are included to aid in reader understanding. The book also discusses specific properties of antennas including brightness and noise temperature, directivity, and polarization, and covers the technical characteristics of interplanetary probes such as Voyager, Cassini, Mars Odyssey, and others. Additional topics in Reception of Weak Radio Signals from Space include: Microwave receivers, covering noise matching, cooled amplifiers, noise figure measurement, and low-noise amplifiers for 1.3 and 10 GHz bands Wave propagation in free space and the influence of the atmosphere via precipitation clouds and the ionosphere, including techniques for measuring the figure of merit G/T of the receiving system Local oscillators, including direct digital and phase-locked loop synthesizers High-frequency rectangular and circular waveguides and coaxial and planar transmission lines Parabolic antennas, describing mirror geometry and its radiation as well as scalar radiator feeds Reception of Weak Radio Signals from Space is an excellent resource on up-to-date information for engineers and scientists working in space communications as well as graduate and senior undergraduate students and radio amateurs.

Table of Contents:
List of Symbols ix List of Abbreviations xv Preface xix Acknowledgments xxv 1 Thermal Noise 1 Reference 3 2 Properties of Antennas 5 2.1 Absolute Black-Body Radiation 5 2.2 Brightness and Noise Temperature of Antennas 6 2.3 Near Field and Far Field 8 2.4 Directivity and Antenna Gain 10 2.5 Polarization 12 References 14 3 Two-Port Network Noise Figure and Equivalent Noise Temperature 15 3.1 Noise Figure of Radio Frequency Attenuator 16 3.2 Noise Bandwidth 17 3.3 System Noise Temperature 17 3.4 Figure of Merit G/T 18 References 19 4 Communication Equation 21 References 23 5 Wave Propagation 25 5.1 Free Space Wave Propagation 25 5.2 Influence of the Atmosphere 26 5.2.1 Precipitation Cloud in Front of Antenna 26 5.2.2 Ionosphere Influence 28 5.3 Wave Propagation by Reflection 30 References 31 6 Measuring the Figure of Merit G/T of the Receiving System 33 6.1 Y-Factor 33 6.2 Measuring G/T Using the Moon 36 6.3 Measuring G/T Using the Sun 40 6.4 Measuring G/T Using Other Space Objects 48 References 49 7 Parabolic Antennas 51 7.1 Reflector Geometry and Its Irradiation 51 7.1.1 Antenna with Rotationally Symmetric Reflector 52 7.1.2 Antenna with Offset Reflector 53 7.1.3 Antennas with Dual Optics 55 7.1.4 Accuracy of Parabolic Reflectors 56 7.2 Feeds 56 7.2.1 Open Circular Waveguide in 10 GHz Band 58 7.2.2 Open Circular Waveguide with Simple Choke 59 7.2.3 Scalar Feed 61 7.2.4 Horn with Rings 62 7.2.5 Horn for 10 GHz and Offset Reflector with f /d = 0.8 63 7.2.6 Horn for 24 GHz and Offset Reflector with f /d = 0.8 64 7.2.7 Horn for 24 GHz and Offset Reflector with f /d = 0.6 66 7.2.8 Standard Horn for 1.3 GHz and Offset Reflector with f /d = 0.8 68 References 71 8 High-Frequency Transmission Lines – Waveguides 73 8.1 Rectangular Waveguides 75 8.1.1 Reactance Elements in a Rectangular Waveguide 77 8.2 Circular Waveguides 80 8.3 Coaxial Transmission Lines 82 8.4 Planar Transmission Lines 84 8.5 Nonreciprocal Microwave Lines 86 References 92 9 Microwave Receivers 93 9.1 Low-Noise Amplifiers 98 9.1.1 Noise Matching 100 9.1.2 Cooled Amplifiers 100 9.1.3 Measurement of Noise Figure 104 9.1.4 Low-Noise Amplifier for 1.3 GHz 109 9.1.5 Low-Noise Amplifier for 10 GHz 117 References 120 10 Local Oscillators 121 10.1 Classification of Frequency Synthesizers 122 10.1.1 Coherent and Incoherent Synthesizers 122 10.1.2 Synthesizers with Direct and Indirect Synthesis 122 10.2 Direct Digital Frequency Synthesizers – DDFS 123 10.2.1 Basic Description 123 10.2.2 Spectral Properties of DDFS 124 10.3 Phase-Locked Loop Synthesizers 128 10.3.1 Time and Frequency Domain Description of a Phase-Locked Loop 128 10.3.2 Order and Type of Phase-Locked Loop 132 10.3.3 Phase-Locked Loop Synthesizers 132 10.3.4 Phase-Locked Loop Stability 133 10.3.5 Classification of Phase-Locked Loops 133 10.3.6 Spectral Properties of PLL Synthesizers 134 10.3.7 Allan’s Variance 136 10.3.8 Circuitry of Modern PLL Synthesizers 138 10.3.9 Oscillators 139 10.3.10 Phase Frequency Detectors – PFD 141 10.3.11 Frequency Dividers 142 10.3.12 Loop Filters 143 10.4 Direct Digital Synthesizer with AD9951EP 145 10.5 Frequency Synthesizer for Microwave Devices 147 References 151 11 Microwave Transmitters 153 11.1 UHF Band Power Amplifier 300 W 154 11.2 X-Band Power Amplifiers 157 11.2.1 Single-Stage X-Band 4 W Power Amplifier 160 11.2.2 X-Band 20 W Power Amplifier 161 11.2.3 X-Band 50 W Power Amplifier 161 11.2.3.1 Calculation of Cooling 167 References 173 12 Communication by Lunar Surface Reflection 175 12.1 Lunar Surface as a Reflecting Surface 175 12.1.1 Reflected Signal Spectrum Broadening 176 12.1.2 Doppler Shift 177 12.1.3 Polarization of Signals 178 12.2 Digital Communication 179 12.2.1 Jt 65 180 12.2.2 Jt 4 180 12.2.3 Qra 64 181 12.2.4 Q 65 183 12.3 Parameters of Communication Devices 185 12.3.1 Antennas 186 12.3.2 System Noise Temperature 187 12.3.3 Echo 187 12.3.4 Accuracy and Stability of Frequency 192 12.3.5 Doppler Shift Compensation 193 12.4 Conclusion 194 References 194 13 Radio Communication with Interplanetary Spacecrafts 197 13.1 Terrestrial Segment for Deep Space Communication 197 13.2 Interplanetary Spacecrafts 200 13.2.1 Voyager 200 13.2.2 Cassini-Huygens 204 13.2.3 New Horizons 205 13.2.4 Mars Odyssey and Reconnaissance Orbiter 207 13.2.5 Spacecrafts at Lagrange Points 207 References 208 14 Conclusion 209 Index 211

About the Author :
Miroslav Kasal, PhD, is a Professor Emeritus at Brno University of Technology (BUT) in the Czech Republic. He was previously a scientific worker at the Institute of Scientific Instruments within the Academy of Sciences of the Czech Republic’s Department of RF Spectroscopy. He last held the position of Department Head. He is an experienced experimenter and lifelong active amateur radio operator with a vast amount of theoretical knowledge and practical experience in the field.