NI AWR Design Environment Radar Design Solutions

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2 ni.com/awr NI AWR Design Environment Radar Design Solutions

3 NI AWR Design Environment - At a Glance Fully Integrated Design Platform Microwave Office - MMIC, RF PCB and module circuit design Visual System Simulator RF/Communications/Radar systems design AXIEM - 3D planar electromagnetic (EM) analysis Analyst - 3D finite element method (FEM) EM analysis Analog Office - Analog/RFIC circuit design NEW: AntSyn Antenna synthesis and optimization Global Presence (Sales & support office loations) California, Wisconsin, Colorado, Massachusetts United Kingdom, Finland, France and Germany Japan, Korea, Taiwan, China and Australia ni.com/awr 3

Visual System Simulator for Radar Design VSS provides detailed behavioral modeling of the RF and signal processing of a radar system, including simulated or measured 3D antenna patterns Features at a

4 Visual System Simulator for Radar Design VSS provides detailed behavioral modeling of the RF and signal processing of a radar system, including simulated or measured 3D antenna patterns Features at a Glance Models include : RF components, Signal processing and antenna models Signal processing blocks Moving target indicator (MTI) Moving target detection (MTD) Constant false alarm rate (CFAR) Antenna model Accept gain pattern Phased array element Channel model Doppler Clutter Target model Radar cross section (RCS) Radar signal generators ni.com/awr 4

Visual System Simulator for Radar Design Supports signal processing algorithm modeling and

provides Budget, line-up and spurious analyses for RF architectures Target detection

measurements LabVIEW compatability LabVIEW or VSS VSS (SW) or PXI (HW) Pulse Generator

5 Visual System Simulator for Radar Design Supports signal processing algorithm modeling and debugging languages such as C++, LabVIEW, MATLAB and VBA Frequency domain simulation provides Budget, line-up and spurious analyses for RF architectures Target detection Antenna and phased array models based on 3D and planar EM simulators or data from range measurements LabVIEW compatability LabVIEW or VSS VSS (SW) or PXI (HW) Pulse Generator Signal Processing Transmitter LO Receiver VSS Antenna VSS Target LabVIEW or VSS ni.com/awr VSS (SW) or PXI (HW) 5

FURUNO: First Pass Success Design-to-Deployment With NI The Challenge: Designed to predict weather and monitor

FURUNO set out to develop a compact, low-cost weather radar system with flexibility in the signal-processing unit to

co-simulating the digital and analog sections.

6 FURUNO: First Pass Success Design-to-Deployment With NI The Challenge: Designed to predict weather and monitor hurricanes and rain fronts, weather radar systems can be large in size. FURUNO set out to develop a compact, low-cost weather radar system with flexibility in the signal-processing unit to accommodate various potential design changes, incorporating a way to verify the system-level performance by co-simulating the digital and analog sections. The Solution: Adopting the NI platform to take advantage of the co-simulation capability between Visual System Simulator (VSS) and LabVIEW software allowed us to realize the system-level simulation of digital and analog sections together. ni.com/awr 6

7 Learn More Online ni.com/awr awr.tv ni.com/awr 7

aspx?productid=395134 http://www.theiet.org/resources/books/telecom/tsddcfe.cfm Broadband Communications and Home Networking http://sci.styluspub.com/books/bookdetail.aspx?productid=369239 http://digital-library.

9 Scott R. Bullock BSEE BYU, MSEE U of U, PE, 19 US Patents, 23 Trade Secrets Books & Publications Transceiver and System Design for Digital Communications, 4 th edition Broadband Communications and Home Networking Multiple Articles in Microwaves & RF, MSN Seminars - Raytheon, L-3, Thales, MKS/ENI, CIA, NASA, Titan, Phonex, NGC, Others Courses for Besser Associates Introduction to RADAR - Transceiver and Systems Design for Digital Communications, Radar, and Cognitive Processes new 5-day course - Includes Directional Volume Search, Acquisition, Track Introduction to Wireless Communications Systems - Transceiver and Systems Design for Digital Communications - Cognitive Radios, Networks, and Systems for Digital Communications - College Instructor Graduate Presentation on Multiple Access to Polytechnic, Farmingdale//Brooklyn, NY Advanced Communications, ITT Engineering 201E, PIMA Key Designs Radar Simulator for NWS China Lake Acquisition, Target Tracking, Missile Tracking, MTI Navy s Integrated Topside INTOP Integrate Radar with EW, EA, Comms Radar Communications using CP-PSK Modulated Pulses for the SPY-3 Radar and PCM/PPM 9

10 RAdio Detecting And Ranging RADAR RADAR is a method of using electromagnetic waves to determine the position (range and direction), velocity and identifying characteristics of targets. 10

11 Radar Applications Military Search and Detection Targeting and Target Tracking Missile Guidance Fire Control Acquisition, Track Airborne Intercept Ground and Battle field Surveillance Air Mapping Systems Submarine and Sub-Chasers Commercial Weather, Navigation, Air Traffic Control Space and Range Road and Speeding Biological Research Bird and Insect Surveillance and Tracking Medical diagnosis, organ movements, water condensation in the lungs, monitor heart rate and pulmonary motion, range(distance), remote sensor of heart and respiration rates without electrodes, patient movement and falls in the home Miniature Seeing aids, early warning collision detection and situational awareness 11

12 Two Basic Radar Types Pulse Radar Transmits a pulse stream with a low duty cycle Receives reflected pulses during the time off or dead time between pulses Single Antenna Determines Range and Altitude Susceptible To Jamming Physical Range Determined By PW and PRF Low average power Time synchronization Continuous Wave CW Radar Transmits a CW signal and receives a Doppler frequency for moving targets Frequency Modulated CW FM-CW also provides both range and velocity Requires 2 Antennas and high SNR More Difficult to Jam But Easily Deceived Simpler to operate, timing not required 12

13 Pulsed Radar Most radar systems are pulsed Transmit a pulse and then listen for receive signals, or echoes Avoids problem of a sensitive receiver simultaneously operating with a high power transmitter. Radar transmits a low duty cycle, short duration high-power RFpulses Time synchronization between the transmitter and receiver of a radar set is required for range measurement. Returns that come from the 1 st pulse causes distortion in the returns after the next pulse 13

14 Radar Modulation 100% Amplitude Modulation AM, ON/OFF keying Turns on/off a carrier frequency Pulse Width PW amount of time that the radar is on for one pulse Determines the minimum range resolution Pulse Repetition Frequency PRF = number of pulses per second Pulse Repetition Interval PRI is the time between the start of the pulses Pulse Repetition Time PRT = Pulse Repetition Interval PRI = 1/PRF PRF can determine the radar s maximum detection range 14

15 Radar Turns on/off the Carrier Frequency Pulse Width = 1us V t carrier wave = 4cycles/1us = 4MHz Pulse repetition time = PRI = 7us = 1/PRF PRF = 1/7us = 143 khz Burst of Carrier Frequency Radar burst Low duty cycle, high power Duty cycle = PW/PRI x 100 = 1us/7us x 100 = 14% 15 Bullock Engineering Research Copyright 2014

16 Basic Radar Uses On/Off Keying of a CW Waveform Radar PW/PRF Control V PW PRI = PRT PRF = 1/PRI Pulse Train: PRF t Modulator On/Off Switch V PW PRI = PRT PRF = 1/PRI Radar Pulses t Oscillator Continuous Waveform - CW 16 Bullock Engineering Research Copyright 2014

17 Pulse Distortion V P1 P2 t PRI = 1/PRF Long P1 returns cause distortion to P2 returns Long returns from P1 causes distortion to the returns of P2 17

18 Basic RADAR Target Transmit Radar Pulse Reflection off a Target Radar Directional Antenna 18

20 Radar Path Budget Tracks Signal & Noise Levels from Radar to Target back to Radar Power Out (PA), Tx Losses, Tx Ant Gain, Channel Losses, Target Reflectivity, Channel Losses, Rx Ant Gain, Rx Losses, Rx Detect S/N Required S/N Radar Budget - Allocation of Power and Noise Radar Tx PA to Radar Rx Detector (LNA) Used in Solving Tradeoffs Size, cost, range Radar pulses are reflected off targets that are in the transmission path Targets scatter electromagnetic energy Some of the energy is scattered back toward the radar Provides gain referenced to an isotropic reflector, similar to antenna gain 20

21 Effective Isotropic Radiated Power EIRP Target RF Power RF Power Gain Target EIRP = Effective Isotropic Radiated Power = RF Power x Antenna Gain ERP = Effective Radiated Power EIRP = ERP + G dipole (2.14dB) ERP = EIRP - G dipole (2.14dB) Bullock Engineering Research 21 Copyright 2014

22 Focusing Increases Power To Provide Gain Focusing Sun Rays To Increase Power Sun Focusing Radio Waves To Increase Power Receiver Magnifying Glass Directional Antenna Bullock Engineering Research 22 Copyright 2014

23 Radar Cross Section RCS RCS (s) - size and ability of a target to reflect radar energy m² RCS(s) = Projected cross section x Reflectivity x Directivity The target radar cross sectional area depends on: Target s physical geometry and exterior features Direction of the illuminating radar Transmitted frequency, Material types of the reflecting surface. Difficult to estimate Equals the target s cross-sectional area theoretically Not all reflected energy is distributed in all directions Some energy is absorbed Usually measured for accurate results 23

24 Radar RCS Patterns Sphere s = pr 2 Flat Plate Similar to Antenna Gains Corner Reflector 24

25 Radar Transmitter Power to Target Power at Target (ideal) EIRP Transmitter P t G t Freespace Attenuation Water Vapor Rain Loss L Atmos Oxygen Multipath Absorption Loss L t = L Atmos x L multi L multi Reflector Target Power at Target Including other losses Bullock Engineering Research 25 Copyright 2014

26 Radar Received Power from Target P targ Reflector Target P r G r Multipath Loss Water Vapor Rain Loss Oxygen Absorption Freespace Attenuation Receiver L multi L t = L Atmos x L multi L Atmos Power received at Radar (ideal) Power at Radar including losses Bullock Engineering Research 26 Copyright 2014

27 Radar Antenna Gain and Channel Losses Transmitter Duplexer Receiver P t P r G t G r EIRP Freespace Attenuation Water Vapor Multipath Water Loss Vapor L multi L t = L Atmos x L multi Rain Oxygen Multipath Loss Absorption Loss L Atmos L Atmos L t = L Atmos x L multi L multi Freespace Rain Oxygen Attenuation Loss Absorption Reflector Target Power at Radar (Ideal) Including other losses in the path One-way Loss: L t = L Atmos x L multi Two-way Losses = L t x L t = L t 2 = L s Bullock Engineering Research Assume Antenna Gain G t = G r 27 Copyright 2014

28 Radar Example Transmitter Duplexer Receiver P t P r G t G r EIRP Freespace Attenuation Water Vapor Multipath Water Loss Vapor L multi L t = L Atmos x L multi Rain Oxygen Multipath Loss Absorption Loss L Atmos L Atmos L t = L Atmos x L multi L multi Freespace Rain Oxygen Attenuation Loss Absorption Reflector Target Given: What is P r in dbm? f = 2.4 GHz,, l =.125 P t = 100W R = 1000m G t = G r = 1000 Total 2-way loss Ls = 10 s= 140 m 2 Bullock Engineering Research P r = 100(1000) 2 (.125) 2 (140) (4p) 3 (1000) 4 (10) = x10-8 W = x10-5 mw P rdbm = 10log( x10-5 ) = dbm 28 Copyright 2014

29 Free Space Attenuation Forms of free-space attenuation depends on how it is used Afs = (l/(4pr)) 2 will be less than 1 and multiplied Afs = ((4pR)/l) 2 will be greated than 1 and divided Afs = 10log (l/(4pr)) 2 = 20log l/(4pr) = will be a negative number and added Afs = 10log ((4pR)/l) 2 = 20log (4pR)/l = will be a positive number and subtracted Important to determine if it is added or subtracted to avoid mistakes Given: P t = 100W = 50dBm, l =.125, R = 1000m Afs = (l/(4pr)) 2 = 98.9 x need to multiply: P r = 100W x 98.9 x = 9.89 x 10-9 Afs = ((4pR)/l) 2 = x need to divide: P r = 100W/( x )= 9.89 x 10-9 Afs = 20log l/(4pr) = -100 db need to sum: P r = 50dBm + (-100dB) = -50dBm Afs = 20log (4pR)/l = 100 db need to subtract: P r = 50dBm - 100dB) = -50dBm 29

30 Two-Way Radar Losses in db Two-way free space loss in db Once for the radar transmitter to target path Once for the target to radar receiver path Total Free Space Loss = Afs db + Afs db = 2 x Afs db = 2 x 20log l/(4pr) Two-way Losses in Radar in db Atmospheric loss 2 x L atmos db Multipath loss 2 x L mult db T/R switch or Circulator loss 2 x L tr db Antenna loss, Polarization, Mis-pointing, Radome 2 x L ant db Implementation loss 2 x L i db Losses in db: L total db = 2 x L atmos db + 2 x L mult db + 2 x L tr db + 2 x L ant db + 2 x L i db 30

31 RADAR Equation to Assess Radar Performance P r = Radar received power P t = Radar transmitted power G t = Transmitter antenna gain G r = Receiver antenna gain G 2 = G r G t assumes the same antenna at the radar l = wavelength R = slant range L s = total two-way additional losses s = radar cross section of the target RCS Log Form P r = P t G tg r A fs A fs G targ 1/L s 10logP r = 10logP t + 10logG + 10logG + 10logA fs + 10logA fs + 10logG target - 10log(L s ) P r dbm = P t dbm + 2G db + 2A fs db + G target db L s db P(mW) = dbm or P(W) = dbw 31

32 Radar Example in db Transmitter Duplexer Receiver P t P r G t G r EIRP Freespace Attenuation Water Vapor Multipath Water Loss Vapor L multi Rain Oxygen Multipath Loss Absorption Loss L Atmos L t = L Atmos x L multi L Atmos L t = L Atmos x L multi L multi Freespace Rain Oxygen Attenuation Loss Absorption Reflector Target Given: What is P r? f = 2.4 GHz,, l =.125 P t = 100W = 50dBm R = 1000m G t = G r = 1000 = 30dB Total 2-way loss Ls = 10 = 10dB s= 140 m 2 A fsdb = 10log(l 2 /(4pR) 2 ) = 20log(l/(4pR) = 20log[(.125)/(4p1000)] = dB G targ = 10log(4ps/l 2 ) = 10log(4p x 140/ ) = 50.5dB P r dbm = P t dbm + 2G db + 2A fs db + G target db L s db P r dbm = 50dBm + 2 x 30dB + 2 x db db 10dB = dBm Bullock Engineering Research 32 Copyright 2014

33 Range Determination Range calculation uses time delay between objects Time delay is measured from source to reflector and back Time delay divided by two to calculate one way range Sound-wave reflection Shout in direction of a sound-reflecting object and hear the echo Calculate two-way distance using speed of sound 1125 ft/sec in air Measure two way delay of 5 seconds Range = 1125ft/sec x 5/2 = 2812ft Measure distance to lighting using the time arrival of the thunder 33

34 Sound Wave Reflection Hi Hi Determine the distance using range formula Listen to multiple echoes off difference distances Best echo effects when the yell is short short pulse width Bullock Engineering Research 34 Copyright 2014

35 Sound Wave Reflection Hi Hi Determine the distance using range formula Listen to multiple echoes off difference distances Best echo effects when the yell is short short pulse width Bullock Engineering Research 35 Copyright 2014

36 Radar Range Calculation Radar uses electromagnetic energy pulses Pulse travel at the speed of light c o Reflects off of a surface and returns an echo back to the radar Calculates the two-way distance or slant range Slant range = line-of-sight distance from radar to target Takes in account the angle from the earth Ground range = horizontal distance from radar to target Slant range calculated using ground range and elevation Radar energy to the target drops proportional to range squared. Reflected energy to the radar drops by a factor of range squared Received power drops with the fourth power of the range Need very large dynamic ranges in the receive signal processing Need to detect very small signals in the presence of large interfering signals 36

37 Slant Range R slant 2 = R gnd 2 + EL 2 : R slant = (R gnd 2 + EL 2 ) 1/2 Target Sinf = El/R slant : R slant = El/sinf Cosf = R gnd /R slant : R gnd = R slant x cosf Slant Range = R slant Elevation = EL Given: Elevation = 5000 ft Angle = 30 0 Radar Directional Antenna f Ground Range = R gnd Calculate Slant Range = R slant = El/sinf = 5000/sin(30) = 10,000 ft What is the Ground Range = R gnd = R slant x cosf = 10,000 x cos(30) = ft R slant 2 = R gnd 2 + EL 2 : R gnd = (R slant 2 - EL 2 ) 1/2 = (10, ) 1/2 = ft 37

38 Range Calculation Electromagnetic energy pulse travels at the speed of light c o R = slant range t delay = two way time delay Radar-Target-Radar c o = speed of light = 3 x 10 8 m/s Given: t delay = 1ms Calculate Slant Range = R = (1ms x 3 x 10 8 m/s)/2 = 150km 38

Radar Range Equation Basic Radar Equation Radar Range Equation (solving for R max range for minimum signal S min ): Double the range requires 16 times more transmit

39 Radar Range Equation Basic Radar Equation Radar Range Equation (solving for R max range for minimum signal S min ): Double the range requires 16 times more transmit power P t Radar detection range = the maximum range at which a Target has a high probability of being detected by the radar Bullock Engineering Research 39 Copyright 2014

Range Ambiguity Caused by strong targets at a range in excess of the pulse repetition interval or time Pulse return from the first pulse comes after the second pulse is sent This causes the range to

40 Range Ambiguity Caused by strong targets at a range in excess of the pulse repetition interval or time Pulse return from the first pulse comes after the second pulse is sent This causes the range to be close instead of far away Radar does not know which pulse is being returned Large pulse amplitude and higher PRF amplifies the problem The maximum unambiguous range for given radar system can be determined by using the formula: Example: PRI = 1msec, T = 1us Calculate Max unambiguous Range = (1ms 1us) x 3 x 10 8 /2 = 149.9km 40

41 Range Ambiguity V P1 P2 t PRI Range Ambiguities 41

42 Range Ambiguity Mitigation Decreasing the PRF reduces the range ambiguity Longer the time delay, higher free-space loss, smaller the return Transmit different pulses at each PRF interval Higher receiver complexity Requires multiple matched filters at each range bin and at each azimuth and elevation Increases rate of the DSP required for each separate transmit pulse and matched filter pair Vary the PRF, depending radar s operational mode Requires changing the system parameters Used most often to mitigate range ambiguity Used in the presence of other jamming pulses Desired returns from the second pulse move with the PRF Undesired returns do not move since they are reference to the first pulse Changing the PRF allows Radar Communications using PPM 42

43 Minimum Detectable Range Radar minimum detectable range return cannot come back during pulse width T = Pulse width, T recovery = time for pulse to recover V P1 R1 R2 R3 Minimum Detectable Range Pulse Does not interfere with the Radar pulse T min for R min = Pulsewidth t Very close range targets equivalent to the pulse width not be detected Typical value of 1 μs for the pulse width of short range radar corresponds to a minimum range of about 150 m Longer pulse widths have a bigger problem Typical pulse width T assuming recovery time of zero: Air-defense radar: up to 800 μs (R min = 120 km) ATC air surveillance radar: 1.5 μs (R min = 225 m) Surface movement radar: 100 ns (R min = 15 m) 43

44 Plan Position Indicator (PPI) The return is displayed on a Plan Position Indicator (PPI) Rotating Search Radars illuminates the targets on the PPI according to the angle received Range is displayed according to the distance from the center of the PPI Uses a range gate to lock on the range of the PPI 44

45 PPI and A-Scope Displays N PPI 0 0 V A-Scope AoA = 77 0 t Range Gate 90 0 Range Gate S 45

For more information on this subject and more, please consider attending;

46 Besser Associates Besser Associates, Inc All rights reserved Thank you for Attending! For more information on this subject and more, please consider attending; Transceiver and Systems Design for Digital Communications, Radar, and Cognitive Processes August 22 to 26 in San Jose, CA Contact us at

RF and Microwave Test and Design Roadshow 5 Locations across Australia and New Zealand

RF and Microwave Test and Design Roadshow 5 Locations across Australia and New Zealand ni.com Design and test of RADAR systems Agenda Radar Overview Tools Overview VSS LabVIEW PXI Design and Simulation