2014-10-16 ATC Design Study UWB Radar System 33

8/10/2019 2014-10-16 ATC Design Study UWB Radar System 33

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The 2014 International Conference on Advanced Technologies for Communications

October 15-17 2014, Ha Noi, Vietnam

Design and Experimental Study of an

Ultra-Wideband Radar System

Manh Ha Hoang

Hong Phuong PhanQuoc Huy Dien

Duc Lam Nguyen

([email protected])


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Outline

2

Introduction

Antennas design

Experimental study of the UWB Radar System

Discussion

Conclusion


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Introduction

Ground Penetrating Radar is used as non-destructive

testing method.

GPRs have many applications in our life

testing structural concrete in civil engineering

emergency rescue

mine detection in military

detection of historical objects in archeology underground storage tank investigation, etc.

UWB is an attractive choice for GPR technology

high speed

high resolution Commercial GPR systems with very high prices

A whole hardware and software of the UWB radar system

has implemented at HCMC University.


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4

Antennas design (1/2)

Frequency band 1 9 GHz

Vivaldi antennas are suitable

upper frequency is theoretical

infinity

planar structure

Design is based on Vivaldi curves

theory Curves are smooth and continuous

to reduce the wave reflection

120x120 mm2 dimension antenna

was designed on Teflon substrate

top view bottom view


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Antennas design (2/2)

Slight reflected pulse over the

time

Lower frequency is 0.972 GHz,

and upper one is above 10GHz

The main radiation direction at

6 GHz with directivity of 7.9dBi When two antennas are on the

same plane |S21|

Results

Time response

|S11|

Directivity


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Experimental study of the UWB Radar System (1/7)

Transceiver, two antennas (Fig.1) The transmitter generates pulses with

spectrum spreading approximately 10GHz

(20dB-bandwidth) (Fig.2)

PID controlled two-dimensional

positioning scanner (Fig.3) PC + Software with migration

algorithms

System

0.5m

10GHz,

-60dBm

-40dBm

Fig.1

Fig.2

Fig.3


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Received signal is continuousand need to be divided into

periods.

base on the reference signal

Signal is received on PC is not

synchronized to the signal fromRadar and it has jitters

interpolating and re-sampling this

signal base on the reference signal

Vibration effects on the received

signal when changing position ofRadar

stopping scanner for an amount of

time enough for stabilizing and

some periods of signal are selected

to make average ones

Problems

Referencesignal

Coupling betweentwo antennas

a period

Vibration


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Use Rada to scan the space at redefined locations, Register received signal and transfer data to PC,

Divide signal into periods base on reference signal,

Select periods at positions the scanner stop,

Make averaged signals and re-sampling these signals base on

the reference signal and averaged period,

Remove environment background data,

Use the migration algorithms Hyperbolic summation (HS),

Kirchhoff migration (KM), Frequency wavenumber migration

(FK), and Phase shift (PS) to recover objects images,

Display the recovered images of the object(s).

Data acquisition and processing process


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Two objects under test

are a rectangular box

and a sphere covered by

foil.

Testing has beenperformed to detect one

or two object(s) in the air

and behind the wall.

Testing arrangement 145mm172mm

145mm125mm

Fig.1

330mm

100mm

100mm

320mm

Fig.2

Fig.3

Fig.4


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Results (1/3)

a b c

d e

Experiments results with two

objects under test in the air

(a) B-scan

(b) HS algorithm(c) KM algorithm

(d) FK algorithm

(e) PS algorithm


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Results (2/3)

a

b c

d eExperiments results with two

objects under test behind the

wall

(a) B-scan(b) HS algorithm

(c) KM algorithm

(d) FK algorithm

(e) PS algorithm


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Results (3/3)

Fig.1 Table 1

Fig.2


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Discussion

New results

High sensitivity

Real time response

Applications of UWB

Radar?

detect structural defects in

civil engineering

emergency rescue

2x2cm2


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Conclusion

A partial design and experimental study of an UWB radar

system has been presented.

The Vivaldi antenna has a good performance and is suitable for

UWB radar systems.

The UWB radar system has been tested to detect objects in

some cases, the objects are in the air and behind the wall. Four migration algorithms HS, KM, FK, and PS have been used

to recover objects images.

The advantage of our system is its high resolution/accuracy

and applying this system to detect structural defects in civil

engineering, or the other is very promising.

Th 2014 I t ti l C f Ad d T h l i f C i ti


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The 2014 International Conference on Advanced Technologies for Communications

October 15-17 2014, Ha Noi, Vietnam

THANK YOU FOR YOUR ATTENTION!

QUESTIONS?

Manh Ha Hoang

([email protected])

Design and Experimental Study of an Ultra-Wideband Radar System

2014-10-16 ATC Design Study UWB Radar System 33

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