Reception of Weak Radio Signals from Space

by Miroslav Kasal

Overview

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.

Product Details

ISBN-13:	9781394292738
Publisher:	Wiley
Publication date:	08/26/2025
Pages:	240
Product dimensions:	6.50(w) x 1.50(h) x 9.50(d)

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.

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