NORTH ATLANTIC TREATY SCIENCE AND TECHNOLOGY ORGANIZATION ORGANIZATION AC/323(SET-182)TP/695 www.sto.nato.int STO TECHNICAL REPORT TR-SET-182 Radar Spectrum Engineering and Management (Ingénierie et gestion du spectre radar) Final Report of Task Group SET-182. Published April 2016 Distribution and Availability on Back Cover NORTH ATLANTIC TREATY SCIENCE AND TECHNOLOGY ORGANIZATION ORGANIZATION AC/323(SET-182)TP/695 www.sto.nato.int STO TECHNICAL REPORT TR-SET-182 Radar Spectrum Engineering and Management (Ingénierie et gestion du spectre radar) Final Report of Task Group SET-182. The NATO Science and Technology Organization Science & Technology (S&T) in the NATO context is defined as the selective and rigorous generation and application of state-of-the-art, validated knowledge for defence and security purposes. 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Requests to do so should be sent to the address on the back cover. ii STO-TR-SET-182 Table of Contents Page List of Figures vii List of Tables x List of Acronyms xi SET-182 Membership List xv Executive Summary and Synthèse ES-1 Chapter 1 – Introduction 1-1 1.1 Context 1-1 1.1.1 Adjacent-Band Interference Mitigation for Radar Emissions 1-2 1.1.2 Adaptive/Cognitive Emission Control 1-5 1.1.3 Electromagnetic Compatibility (EMC) 1-6 1.1.4 Receiver Interference Rejection 1-6 1.2 Objectives 1-7 1.3 Study Organization 1-7 1.4 Report Structure 1-7 Chapter 2 – Improved Transmitter Spectral Purity 2-1 2.1 Introduction 2-1 2.2 Background on Spectral Cleanliness 2-3 2.2.1 Spectrally Clean Waveform Formulation 2-4 2.2.2 Spectrally Clean Transmitter Design 2-7 2.2.3 Other Recent and Current Efforts on Improving Transmitter 2-10 Spectral Cleanliness 2.2.4 Technology Watch: Adaptive Solid-State Power Amplifiers and 2-11 Optimized Waveforms 2.2.4.1 Description of the Technology 2-11 2.2.4.2 Possible Impact of the Technology on a Military 2-12 Capability 2.4.4.3 Technology Readiness Level 2-13 2.4.4.4 Related to NATO Requirements 2-13 2.3 Controlling the Pulse Rise/Fall Time 2-13 2.3.1 LiNC-PCFM Radar Implementation 2-14 2.4 Reconfigurable Amplifier Design for Flexible Spectral Mask Compliance 2-18 2.4.1 Fast Load-Impedance Search for Power-Added Efficiency and 2-19 Adjacent-Channel Power Ratio 2.4.2 Load Impedance Optimization Based Directly on PAE and Spectral 2-24 Mask Compliance 2.4.3 The Smith Tube for Joint Circuit and Waveform Design 2-27 STO-TR-SET-182 iii 2.4.4 Next Steps in Joint Circuit and Waveform Optimization for 2-31 Spectrally Sensitive, Adaptive Radar Chapter 3 – Better Receivers 3-1 3.1 Introduction 3-1 3.2 Basic Analog Radar Receiver Topology 3-1 3.3 Dynamic Range 3-2 3.4 Mixers and Downconversion 3-3 3.5 Analog Coherent Detection 3-4 3.6 Digital Coherent Detection 3-5 Chapter 4 – Passive Bistatic Radar 4-1 4.1 Background 4-1 4.2 Commensal Radar 4-6 4.3 Vertical-Plane Coverage 4-6 4.4 Conclusions and Recommendations 4-8 Chapter 5 – Cognitive Techniques 5-1 5.1 Introduction 5-1 5.2 Cognition 5-1 5.3 Conclusions and Recommendations 5-5 Chapter 6 – Regulatory Issues 6-1 6.1 Summary 6-1 6.2 Today’s and Future Radar Spectrum Environments 6-1 6.3 Current Issues of Interference Between Wireless and Radar Systems 6-2 6.4 Sharing Studies for Coexistence of Systems in the Same Band 6-4 6.5 Sharing Studies for Coexistence of Systems in Adjacent Bands 6-4 6.6 White Space 6-5 6.7 Current Radar Regulatory Standards 6-5 6.7.1 Regulatory Standards at Worldwide Level – ITU 6-5 6.7.2 Regulatory Standards at European Level – NATO 6-6 6.7.3 Spectrum Enforcement and Legal Issues 6-6 6.7.4 Common Definitions 6-7 6.8 Spectrum Regulatory Discussions 6-8 6.8.1 Spectrum Regulatory Discussions at National Level 6-8 6.8.2 Spectrum Regulatory Discussions at Regional Level 6-8 6.8.3 Spectrum Regulatory Discussions at ITU-R Level 6-8 6.8.4 WRC 2015 Agenda Items Related to Radars 6-9 Chapter 7 – Conclusions and Recommendations 7-1 7.1 Summary and Conclusions 7-1 7.2 Recommendations 7-1 iv STO-TR-SET-182 Chapter 8 – References 8-1 Annex A – List of Meetings A-1 Annex B – Bibliography of Work/Outputs of SET-182 B-1 B.1 Book Chapters B-1 B.2 Journals B-1 B.3 Conferences/Workshops B-2 B.4 Journal Special Issue B-5 B.5 Conference Activities B-5 B.6 Tutorials B-5 B.7 Technical Committee B-6 B.8 SET-204 Two-day Specialists’ Meeting on “Waveform Diversity” B-6 29/30 September 2014, Berlin, Germany Annex C – Summary of SET-066 Report C-1 C.1 Introduction C-1 C.2 The Nature of the Problem C-1 C.3 Objectives C-2 C.4 Report Structure C-3 C.5 Mechanisms Which Cause Interference Between Military Radar and C-3 Civil Telecommunications C.5.1 Challenges Imposed on Radar Services C-3 C.5.1.1 Current Environment C-3 C.5.1.2 Future Environment C-4 C.5.1.3 Technical Reasoning C-5 C.5.1.4 Economic Reasoning C-5 C.5.2 The Nature of Interference C-6 C.5.2.1 In-Band Interference C-8 C.5.2.2 Out-Of-Band (OOB) Interference C-8 C.5.2.3 Spurious Band Interference C-8 C.5.3 Features that Affect the Interference Seen in the System C-9 C.5.3.1 Incident Field Strength C-9 C.5.3.2 Radar Receiver Selectivity C-9 C.5.3.3 Spurious Emission Limits of Interference Source C-10 C.5.3.4 Presence of Spurious Pass-Bands in Victim Receiver C-10 C.5.3.5 Radar Receiver Linearity C-10 C.5.3.6 Interference Frequency Offset C-10 C.5.3.7 Polarisation C-10 C.5.3.8 Modulation or Coding Used in the Radar C-11 C.5.3.9 Radar Receiver/Processor Mode of Operation C-13 C.5.4 Initial Considerations of Interference Mechanisms in the Radar C-13 Receiver C.5.4.1 Consideration of Interference-to-Noise Ratio I/N C-13 C.5.4.2 L-Band Range Reduction Caused by Variation in I/N C-13 STO-TR-SET-182 v C.5.4.3 Hostile Source Transmit Power Required to Cause C-15 Range Reduction C.5.4.4 Variation in Detection Probability (Pd) Due to C-16 Variation in I/N C.5.4.5 Receiver Blocking C-19 C.5.4.6 Range Accuracy C-20 C.5.4.7 Azimuth Accuracy C-21 C.5.4.8 Effects on Other Parameters C-25 C.5.4.9 Permanent Effects C-26 C.5.5 Some Interference Scenarios C-26 C.5.5.1 Scenario 1 – Interference Signals in the Frequency C-26 Domain C.5.5.2 Scenario 2 – Interference in the Time Domain C-29 C.6 Conclusions C-34 C.6.1 General C-34 C.6.2 Antennas C-34 C.6.3 Receivers C-35 C.6.4 Impact on Military Radars C-35 C.6.5 Impact of UWB C-35 C.6.6 Transmitter C-36 C.7 Reference C-36 vi STO-TR-SET-182 List of Figures Figure Page