ni.com

RF and Microwave Test and Design

Roadshow

5 Locations across

Australia and New Zealand

Design and test of

RADAR systems

Agenda

Radar Overview

Tools Overview

VSS

LabVIEW

PXI

Design and Simulation

Simulating the frond end

Modeling signal processing

Prototyping with real hardware

Overview of RADAR

• RADAR = radio detection and ranging

• Radar is an electromagnetic system for the detection and

range of objects

• Where the reflection of the transmitted waveform is used for

detection and range

• And its range (R) is determined by the equation

out R c

back R c 2R out back R c

2R R c

Transmit Pulse

Receive Pulse

Types of RADAR Signals

CW (Continuous Wave)

Detects velocity – but not range

FM CW

Detects range through frequency difference of reflection

Requires separate Tx and Rx Antennas

Pulsed CW

Detects range through round trip time of pulse

Unambiguous range determined by pulse interval

PRF =1

PRIRu =

c

2´PRF

Pulse repetition frequency (PRF) Unambiguous Range

Note on Unambiguous Range

If PRF is 1000Hz then PRI = 1ms

Maximum unambiguous range = 150km

If we distribute the return signal over 200 bins

5us = 150km / 200 = 0.75km resolution

1 2 3 4 200

A target 225km will have a delay of 1.5ms and will be

mapped back to the 100th range bin (0.5ms or 75km).

Hence, this is called range ambiguity.

….….

Channel & Environmental Analog (RF) Baseband

(Digital)

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO

Designing a RADAR System

Target

AWR Visual System Simulator

RADAR Design and Test

Ideal flow enables design tools to be leveraged by test group

PXI and LabVIEW can be used in design-through-test

Focus of Today’s Discussion

Tools Overview

AWR’s Visual System Simulator EDA Solution for System Design

Mode’s include:

Time Domain

Complex Envelope

Spur Analysis

RADAR library includes

Full system simulation

CFAR, MTI, and MDT

Target and antenna modeling

RF Link simulation includes…

Amplifier, Mixer, Filter…

Co-simulate with MWO circuits

Co-simulate with hardware

National Instruments HW and SW NI LabVIEW Software

Graphical programming environment

Instrument control

Signal processing algorithms

Visualization and graphing

NI PXI Hardware

PC-based instruments

RF signal generators and analysers

Signal Processing Visualization & Display Instrument Control

Signal Processing in LabVIEW

Modulation & Demodulation

Signal Creation

Filtering (FIR, IIR, etc.)

Signal Operation

Spectrogram

Connecting LabVIEW and VSS

Characterize simulated RF parts with LabVIEW measurements

Prototype systems designs with physical hardware

Control instruments from AWR’s VSS environment

+

Importing LabVIEW Code in VSS

LabVIEW controls and

indicators get mapped to

input and output ports of

a “LabVIEW Node” on

the VSS diagram

VSS Environment

LabVIEW Environment

RADAR Pulse Generation

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO Target

Chirp Pulse Creation in LabVIEW

Basic chirp signal can be created by FM

modulating a “ramp” message signal.

RADAR Tx Chain Analysis

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO Target

PORTDOUTPORTDIN AMP_B

1 2

NL_S

ISOLATOR

M_PROBE

BPFB

MMIC PA

340MHz

10MHz

8665MHz

9015MHz

Behavioral PA

or

BPFE BPFBBPFBBPFB AMP_BAMP_B

TP

TONETONE

IN OUT

LO

MIXER_B

IN OUT

LO

MIXER_B BPFE

AMP_B

Transmit Chain Analysis

Analysis methods in VSS include

Link budget analysis

Spur analysis

Custom analysis possible in LabVIEW

Link budget Analysis

RFB C_NF for TX

0

1

2

3

4

5

S4\BPFB (F1) S4\AMP_B (A1) S4\BPFB (F2) S4\MIXER_B (Mixer1) S4\BPFE (F3) S4\AMP_B (A2) S4\BPFE (F4) S4\MIXER_B (Mixer2) S4\BPFB (F5) S4\AMP_B (A5) S4\AMP_B (A4) S4\BPFB (F6) S4\ISOLATOR (S8) TX_ANTENNA (S7)

p1

4.647 dB

DB(C_NF(TP.Start,TP.Stop,0,1,0,1))[1]

RFB Tx System

p1: Cascaded Noise Figure, Signal, Cumulative, dBFreq=9015 MHz

RFB Cumulative Gain for TX

-20

0

20

40

60

S4\BPFB (F1) S4\AMP_B (A1) S4\BPFB (F2) S4\MIXER_B (Mixer1) S4\BPFE (F3) S4\AMP_B (A2) S4\BPFE (F4) S4\MIXER_B (Mixer2) S4\BPFB (F5) S4\AMP_B (A5) S4\AMP_B (A4) S4\BPFB (F6) S4\ISOLATOR (S8) TX_ANTENNA (S7)

p1

1459.54 dB

DB(C_GA(TP.Start,TP.Stop,1,0,1))[1]RFB Tx System

p1: Available Gain, Cumulative, dBFreq=9015 MHz

-5000 0 5000 10000 15000 20000 25000 30000 35000 40000

Frequency (MHz)

RFI for TX

-400

-300

-200

-100

0

100

9015 MHz59.55 dBm

Results: • Cascaded NF = 4.65dB

• Available Gain = 59.5dB

• Power level at 9015MHz = 59.55dBm

Gain

Noise Figure

Time Domain Analysis

LabVIEW can be used for custom time domain analysis

Complex signals using the measured phase (Θ) vs. time

Linear pulse phase vs. time has constant change

Θ(t) should have a “U-shape”

dΘ/dt should have a linear slope

d2Θ/dt2 should appear as a DC signal

+

Basic Pulse Analysis in LabVIEW

Second derivative should appear

“DC” on a perfectly linear pulse

First derivative should appear

as a “ramp” on a linear pulse

Input

Waveform

Demo: Measuring Pulse Linearity

Pulse is no longer linear due to group

delay through a narrowband filter.

Generating Pulses with Hardware

PXIe-5673 Vector Signal Generator

• Frequency: 100 MHz to 6.6 GHz

• Phase Noise: -110 dBc/Hz

(10 kHz offset at 1 GHz)

• Bandwidth: up to 100 MHz

QuickSyn Synthesizer

• Frequency: 200 MHz to 20 GHz

• Phase Noise: -138 dBc/Hz

(10 kHz offset at 1 GHz)

• AM, FM, and Pulse modulation

Using a VSA to Analyze Pulses

Phase Matrix VSA

• Frequency Range: 100 kHz to 26.5 GHz

• Phase Noise: -118 dBc/Hz (10 kHz offset

at 1 GHz)

• Bandwidth: up to 350 MHz

PXIe-5665

• Frequency Range: 20 Hz to 14 GHz

• Phase Noise: -130 dBc/Hz (10 kHz

offset at 1 GHz)

• Bandwidth: up to 50 MHz

RADAR Antenna & Target Modeling

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO Target

Antenna Characterization with a VNA

PXIe-5630 VNA

• Frequency: 10 MHz to 6GHz

• Measurements: S11 & S21

• Dynamic Range: >100 dB

• Typical Accuracy: < ± 0.1 dB, 0.1 deg

• Sweep Speed: 400 us/pt

PXI Motion

Control

PXIe-5630

VNA

PXIe

Controller

Motor rotates

antenna

Antenna Modeling

Parameters include

Gain

Effective Area

Efficiency

Directivity

Polarization

VSWR

Free Space Impedance

Zin and Zout respectively

Sets signal power

received at target

according to distance

EIRP

Delay and Doppler due to target

velocity and distance

RCS

PWR

For statistical variation

on RCS

Reflected Signal

Modeling the Target in VSS

RADAR Rx Chain Analysis

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO Target

Receive Chain Analysis

Analysis metrics include

Noise figure/sensitivity

P1dB

Group delay

BPFBAMP_BBPFB

M_PROBE

INOUT

LO

MIXER_B

TONE

BPFEAMP_B

INOUT

LO

MIXER_B BPFE

TONE

AMP_B

BPFBPORTDOUT

PORTDIN

LNA9015MHz

8665MHz

350MHz10MHz

340MHz

Receiver RF Analysis

RFB C_NF for RX

1

1.5

2

2.5

3

3.5

S1\BPFB (F6) S1\AMP_B (A4) S1\BPFB (F1) S1\MIXER_B (A1) S1\BPFE (F4) S1\AMP_B (A2) S1\BPFE (F2) S1\MIXER_B (A3) S1\AMP_B (A6) S1\BPFB (F3)

p9p8p7p6p5p4p3p2p1

3.153 dB

p1: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-70

p2: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-66

p3: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-62

p4: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-58

p5: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-54

p6: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-50

p7: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-46

p8: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-42

p9: Cascaded Noise Figure, Signal, Cumulative, dBFreq=10 MHzPWR=-38

RFB Cascaded Headroom of RX link

-20

0

20

40

60

80

S1\BPFB (F6) S1\AMP_B (A4) S1\BPFB (F1) S1\MIXER_B (A1) S1\BPFE (F4) S1\AMP_B (A2) S1\BPFE (F2) S1\MIXER_B (A3) S1\AMP_B (A6) S1\BPFB (F3)

p2

p1

-1.06 dB

22.9 dB

DB(C_HDRM(TP.Start,TP.End,1,0,1,1,1))[1,T]RFB RX System

DB(C_HDRM(TP.Start,TP.End,1,0,1,1,1))[1,7]RFB RX System

p1: P1dB Headroom, Gain Adjusted, dBFreq=10 MHzPWR=-46

p2: P1dB Headroom, Gain Adjusted, dBFreq=10 MHzPWR=-70

7 9 11 13

RX IF Frequency (MHz)

RFB C_GD RX

0.5

1

1.5

2

Tim

e (

us)

p1

C_GD(TP.Start,TP.End,0,1,0,1,0)[X,T] (us)RFB RX System

p1: Absolute Group Delay, usPWR=-70

P1dB Noise Figure

Group Delay

RADAR Receiver Algorithms

Transmitter

Receiver

Pulse

Generator

Signal

Processing

Antenna LO Target

Receiver Algorithms

Basic Algorithms Range and velocity through correlation

Advanced Algorithms

Enable detections in difficult environments

Examples include: Moving Target Indicator (MTI)

Moving Target Detector (MTD)

Constant False Alarm (CFAR)

Range Detection Through Correlation

Chirp generator

Coupler

Correlator

PORTDIN PORTDOUT

PORTDIN

12

3

SUBCKT

TP

1

2

3

CORRELATOR

1 2

3

DCOUPLER_3

0 20 40 60 80 100 120 140 160 180

Time (us)

Output of Correlator

0

1

2

3

4

41.8 us3.143

|WVFM(S13\TP.Compressed.Chirp,180,4,0,0,0,0,0,0)|

Chirp System

Range from target 6Km

0 20 40 60 80 100 120 140 160 180

Time (us)

Output of Correlator

0

0.05

0.1

0.15

155.9 us0.1475

|WVFM(S13\TP.Compressed.Chirp,180,4,0,0,0,0,0,0)|

Chirp System

Range from target 23Km

To Tx Link

From Tx Link

MDT Algorithm in LabVIEW

Input

Example output of MTD Algorithm

Conclusion

RADAR design requires combination of HW and Software

RF front end design design and test

Receiver algorithm prototyping

National Instruments provides a complete solution for

Visual System simulator for front end simulation

LabVIEW for pulse creation and signal processing

PXI instruments for physical RADAR test