active electronically scanned array

8/6/2019 Active Electronically Scanned Array

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ACTIVE ELECTRONICALLY STEERED ARRAY RADAR


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Outline

What is RADAR?

Radar Scanning?

Phased Array Radars

Progress

Future Tasks


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WHAT IS RADAR?RADAR SCANNING?

PHASED ARRAY RADARS

PROGRESS

FUTURE TASKS

Outline


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What is RADAR?

RADAR an acronym for:

Radio Detection and Ranging

Basic Principles Transmits an electromagnetic signal modulated

with particular type of waveform. (modulationdepends on requirements of application)

Signal is reflected from target

Reflected signal is detected by radar receiver andanalyzed to extract desired information


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Basic Operation [5]

Target Range, R=c t / 2

is needed to account for the two-waytime delay


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Frequency Bands [6]

SRE: Surveillance Radar

ASR: Airport surveillance Radar

PAR: Phased array radar

SMR: Surface movementRadar


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Applications (1/2) [1]

Air Traffic Control

Monitor the location of aircraft in flight

Monitor the location of aircraft/vehicles on surfaceof airports

Air Navigation

Weather radar

Terrain avoidance and terrain following

Radar altimeter


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Applications (2/2) [1]

Marine

Law Enforcement and highway safety

Space Military


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Types [5]

Basic Types

Monostatic - transmitter and receiver use same

antennaPulse Transmission

Bistatic - transmitter and receiver antennas areseparated, sometimes by large distances

Continuous wave Transmission


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Generic Radar System [1]


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Generic Radar System [3]


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Functional Descriptions [3]


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WHAT IS RADAR?

RADAR SCANNING?PHASED ARRAY RADARS

PROGRESS

FUTURE TASKS

Outline


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RADAR scanning [4]

An important part of RADAR architecture

Provides support to the antenna

Directs the antenna beam Transmission & Reception

Types:

Surface based scanning

Air borne scanning


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Common elements of Scanners

(1/2) [4] Antenna

Transmit/ Receive RF energy

Single element/ Array Parabolic reflectors, Aperture antennas etc

Transmission Line

Coaxial line or Wave guides

Special rotary joints required to support scanningrotation


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Common elements of Scanners

(2/2) [4] Scan mechanism

Continuous rotation of the antenna about its axis

Usual rate of rotation 4-6 rpm (ground or shipsearch)

Air-borne rotation at 30 rpm

2D rotation- Complex rotation mechanism

Kinematics of the Scan

Data transmission


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WHAT IS RADAR?

RADAR SCANNING?

PHASED ARRAY RADARSPROGRESS

FUTURE TASKS

Outline


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Phased Array Radars (1/2)

No physical rotation of antenna elements for

Scanning

Phase manipulation/ control of the individualantenna

Constructive and Destructive interference

Beam steering in the particular direction


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Phased Array Radars (1/2)

Demonstration [6]Phase control to

steer antenna

beam in the

desired direction


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Beam steering mathematics [6]

Constant phase increment

x = d sin s

360

=

(2

) x

=

360 d sin s

= phase shift between two successive elementsd= distance between the radiating elements (half the wavelength)

s = beam steering


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Example [6]

A radar set works with a wavelength of=3 cm.

The distance between the radiating elements is 1.5 cm.

The beam steering is s= 40.

Which value shallhave to have the phase shifter no. 8?

=(360*1.5 cm/3 cm)*sin(40) = 115.70.

Phase shift value 8 = 7 115.70 = 809.91.

8= 89.91.


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Whats Unique to PAR?

Parabolic Antenna Single radiation element

Single transmitter

Single receiver

Non-conformal

Fixed beam pattern

Mechanical steering

Phased Array Antenna Multiple radiation

elements

Multiple transmitters

Multiple receivers

Conformal

Variable beam pattern

Electronic steering


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Types of Phased Array Radars

[8] Passive phased array radar

Active phased array radar


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System Components

Amplification, Phase shifting and Attenuators

required at each antenna element

High power amplifiers, Low noise amplifier,Limiters

Transmit and Receive circuitry connected to

each antenna element

TR switch, duplexer


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Transmit/ Receive module [6],

[3]

Single Transmit/ Receive element for Active phased arrayradar


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Phase and Amplitude Control

Adding phase shift in the signal

Null and Side lobe control

Anti Jamming


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Transmission Line Phase

shifters [6]


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Digital Beam Steering/ Forming

[8] Use of computational and programmable

environment

Signal processing in the Digital domain

Phase and Amplitude control


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Digital Beam forming [8]


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WHAT IS RADAR?


PROGRESSFUTURE TASKS

Outline


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1.Simulation: Beam Steering

Bram Steering

4 element antenna array

Center frequency: 8 GHz

Phase shifting

Manually for proof of concept


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1. 4-element array at 8GHz

A1 A2 A3 A4


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1.Results (0,0,0,0)

-80

-60

-40

-20

0 20 40 60 80-100

100

-50

-40

-30

-20

-10

-60

0

THETA

Mag.

[dB

]


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1.0,0,0,30

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

THETA

.[B]

m1

m1THETA=

B(Ecross)=-1.135Max

-3.000


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1.0,0,0,45

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

THETA

Mag.

[B]

m1

m1THETA=

B(Ecross)=-1.120Max

-4.000


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1.0,0,0,90

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

E A

ag.

[

]

1

m1E A=

dB(Ecro =-1.101ax

-7.


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1.0,0,0,120

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

E A

ag.

[dB]

m1

m1E A=

dB(Ecro =-1. 77Max

-10.


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1.0,30,90,150

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

THETA

Mag.

[dB]

m1

m1THETA=dB(Ecross)=-1.091Max

-14.000


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1.0,45,90,135

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

THETA

Mag.

[dB]

m1


-13.000


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1.0,60,120,180

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

T T

Mag.

[d

]

m1

m1T Td ( cross) -1.075Max

-17.000


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1.0,90,180,270

-80

-60

-40

-20

0 20

40

60

80

-100

100

-50

-40

-30

-20

-10

-60

0

THETA

Mag.

[dB]

m1


-26.000


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2.Simulation: System Architecture

Transmitter module

Baseband signal at 100 MHz

RF converted frequency at 10 GHz


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2.Transmitter model

4

4

4

4

TransmitAntenna

HPAGain 5 dB

Wave form GeneratorBaseband Signal 100 MHz

Upconversion StageLO= . GHzRF=10 GHz

````

1 3

1 3

1 3

1 3

Envelope

Env1

Step=10 nsec

Stop=100 nsec

Order[3]=3Order[2]=3

Order[1]=3Freq[3]=10GHz

Freq[2]=1.0 GHzFreq[1]=100MHz

ENVELOPE

Amplifier2AMP4

S12=0

S22=dbpolar(-40,180)S11=dbpolar(-40,0)

S21=dbpolar(20,0)

Amplifier2AMP3

S12=0S22=dbpolar(-40,180)

S11=dbpolar(-40,0)S21=dbpolar(20,0)

Amplifier2

AMP2

S12=0


S21=dbpolar(20,0)

Amplifier2AMP1

S12=0


S21=dbpolar(20,0)

BPF_Chebyshev

BPF7

Astop=30 dBBWstop=8 GHz

Ripple=0.1 dBBWpass=50 MHz

Fcenter=10GHz

Amplifier2IF_Amplifier3

S12=0


S21=dbpolar(30,0)

MixerWithLO

MIX8

ConvGain=dbpolar(18,0)DesiredIF=RF plus LO

ZRef=50 Ohm

antenna_gain

X4

P_1Tone

Source3

Freq=100MHz

P=polar(dbmtow(0),0)Z=50 Ohm

Num=3

Term

Term5

Z=50 Ohm

Num=5

BPF_ChebyshevBPF6

Astop=30 dBBWstop=8 GHz


Fcenter=10GHz

Amplifier2IF_Amplifier2

S12=0S22=dbpolar(-40,180)

S11=dbpolar(-40,0)S21=dbpolar(30,0)

MixerWithLOMIX7


ZRef=50 Ohm

antenna_gainX3

P_1ToneSource2

Freq=100MHz

P=polar(dbmtow(0),0)Z=50 Ohm

Num=2

TermTerm4

Z=50 Ohm

Num=4

BPF_Chebyshev

BPF5

Astop=30 dB

BWstop=8 GHzRipple=0.1 dB

BWpass=50 MHz

Fcenter=10GHz

Amplifier2

IF_Amplifier1

S12=0


S21=dbpolar(30,0)

MixerWithLO

MIX6

ConvGain=dbpolar(18,0)

DesiredIF=RF plus LO

ZRef=50 Ohm

antenna_gain

X2

P_1Tone

Source1

Freq=100MHzP=polar(dbmtow(0),0)

Z=50 OhmNum=1

TermTerm3

Z=50 OhmNum=3

Term

Term2

Z=50 Ohm

Num=2

P_1Tone

Source

Freq=100MHzP=polar(dbmtow(0),0)

Z=50 Ohm

Num=1

antenna_gain

X1

MixerWithLO

MIX5


ZRef=50 Ohm

Amplifier2IF_Amplifier

S12=0


S21=dbpolar(30,0)

BPF_Chebyshev

BPF4

Astop=30 dB

BWstop=8 GHz


Fcenter=10GHz


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2.Baseband spectrum

0.2 0.4 0.6 0.80.0 1.0

-90

-80

-70

-60

- 0

-40

- 0

-20

-10

-100

0

fr GH

B(v

r("1

"))

2m2

fr =

B(v r("1"))=-9.914time=100.0000nsec

100.0MH


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2.RF level: 10 GHz

6 7 8 9 10 11 12 13 145 15

-70

-40

-10

20

-100

50

fr Hz

dB(

ar("4"))

m3

m3frdB( ar("4")) 33.811tim =100.0000ns c

10.00GHz


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2.Receiver Model

LNA stageecei e Antenna Array

a1

Vout4 a4

Vout3 a3

Vout2 a2

Vout1

VA

VA

1

arget_location=-1A

p_gain=30

EqnVar

antenna_gain

antenna2

antenna_gain

antenna4

antenna_gain

antenna3

antenna_gainantenna1

target_phaseshiftertarget_th1

X=

arget_location

A

plifier2

AMP1

12=0

22=polar(0,180)

11=polar(0,0)

21=dbpolar(A

p_gain,0)

A

plifier2

AMP2

12=0

22=polar(0,180)

11=polar(0,0)

21=dbpolar(A

p_gain,0)

A

plifier2AMP3

12=0

22=polar(0,180)

11=polar(0,0)

21=dbpolar(A

p_gain,0)

A

plifier2

AMP4

12=0

22=polar(0,180)

11=polar(0,0)

21=dbpolar(A

p_gain,0)

er

er

4

=50

h

Nu

=4

er

er

3

=50

h

Nu

=3

er

er

2

=50

h

Nu

=2

er

er

1

=50

h

Nu

=1

PF_ utterworth

PF4

Astop=20 d

Wstop=3

HzApass=3.0103 d

Wpass=25 MHzFcenter=1

Hz

PF_ utterworth PF3

Astop=20 d Wstop=3

Hz

Apass=3.0103 d


Hz

PF_ utterworth

PF2

Astop=20 d

Wstop=3

HzApass=3.0103 d


Hz

PF_ utterworth PF1

Astop=20 d

Wstop=3

Hz

Apass=3.0103 d


Hz

Har

onic alance

H 1

rder[1]=6Freq[1]=1.0

Hz

HA

MONI

ALAN

E

Vt

Vt1

Vt1=vt(vout,0,0,10nsec,201)

t

Vt

Vfc

Vfc1

Vfc1=vfc(vout,0,{1})

f

Vf c


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2.Target Model

v_s

v_s

v_s

v_s

Vf_Pulse

SRC4

Harmonics=16

Weight=no

Delay=0 nsec

Fall=0.1 nsec

Rise=0.1 nsec

Width=0.3 nsec

Freq=1 GHz

Vdc=0 VVpeak=1 uV

Vf_PulseSRC3

Harmonics=16

Weight=no

Delay=0 nsec

Fall=0.1 nsec

Rise=0.1 nsec

Width=0.3 nsec

Freq=1 GHz

Vdc=0 V

Vpeak=1 uV

Vf_Pulse

SRC2

Harmonics=16

Weight=noDelay=0 nsec

Fall=0.1 nsec

Rise=0.1 nsecWidth=0.3 nsec

Freq=1 GHz

Vdc=0 V

Vpeak=1 uV

Vf_PulseSRC1

Harmonics=16

Weight=no

Delay=0 nsec

Fall=0.1 nsec

Rise=0.1 nsec

Width=0.3 nsec

Freq=1 GHzVdc=0 V

Vpeak=1 uV

TimeDelay

TD4

ZRef=50. Ohm

Delay=X*0.108e-9

TimeDelay

TD3

ZRef=50. Ohm

Delay=X*0.081e-9

TimeDelayTD1

ZRef=50. Ohm

Delay=X*0.027e-9

TimeDelayTD2

ZRef=50. Ohm

Delay=X*0.054e-9

Port

P4

Num=4

PortP3

Num=3

Port

P2

Num=2

Port

P1

Num=1

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.80.0 2.0

-400

-200

0

200

400

-600

600

time, nsec

ts(Vout1),nV

ts(Vout2),nV

ts(Vout3),nV

ts(Vout4),nV

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.80.0 2.0

0.0

0.2

0.4

0.6

0.8

1.0

-0.2

1.2

time, nsec

ts(v_

s),

V


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2.Target: if Straight

0.2 0.4 0.6 0.8 1.0 1. 2 1.4 1.6 1. 80.0 2.0

-400

-200

0

200

400

-600

600

time, n ec

ts(Vout1,nV

ts(Vout2

,nV

ts(Vout3

,nV

ts(Vout4

,nV

0.6 0.7 0.8 0.9 1.0 1.1 1. 2 1.3 1.40.5 1.5

-130

-120

-110

-100

-90

-140

-80

freq, H

phase(Vout1

phase(Vout2

phase(Vout3

phase(Vout4


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2.In this case, Target Located

10 degrees right

0. 0. 0. 0.

.0 1. 1. 1. 1.

0.0 2.0

-400

-200

0

200

400

-600

600

t me, se

t

s(V

t1),

V

t

s(V

t2),

V

t

s(V

t

),

V

t

s(V

t4),

V

0.6 0.7 0.

0.!

1.0 1.1 1.2 1."

1.40.5 1.5

-130

-120

-110

-100

-90

-140

-80

freq, GHz

phase(V

#

$

t1)

phase(V

#

$

t2)

phase(V

#

$

t3)

phase(V

#

$

t4)


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2.Target Located 10 degrees

left

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.80.0 2.0

-600

-400

-200

0

200

400

600

-800

800

t% &

'

,ns'

c

ts(V

t1),nV

ts(V

t2),nV

ts(V

t3),nV

ts(V

t4),nV

0.6 0.(

0.8 0. ) 1.0 1.1 1.2 1.3 1.40.0

1.0

-0

0

-40

-30

-20

-10

0

10

20

30

40

0

0

-60

60

fr , z

s

(V

t1)

s

(V

t2)

s

(V

t3)

s

(V

t4)


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WHAT IS RADAR?


PROGRESS

FUTURE TASKS

Outline


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Future Tasks

1. System Level simulation

Beam Steering

Complete architecture

2. Component Design

a. Muhammad Usman Afzal

High power Amplifier

Antenna Array


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References

1. ELEC4600 Radar and Navigation

Engineering

2. Radar Principles & Systems byLT Mazat3. Introduction to Radar Systems, MIT Lincoln

Laboratory

4. Radar Scanners & Radomes, MIT radiation

laboratory series

5. Introduction to Radar basics Matlab

simulation for Radar system design


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References

6. www.radartutorial.eu

7. Active Phased Array Radar Systems, Dr.

Yasser Al-Rashid. Lockheed Martin MS2Radar Systems

8. Phased Array Antenna And Beam Forming

Sub-sytems In Phased Array Radar

Dr A. Jhansi Rani, A.Jaya Lakshmi,International Journal of Engineering Science

and Technology

active electronically scanned array

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