,,Nicolae Balcescu,, Land Forces Academy [627473]

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,,Nicolae Balcescu,, Land Forces Academy

BACHELOR THESIS

SUPERVISORS
PD Dr. –Ing.
THOMAS FICKENSCHER
Col. Prof. -Univ. Dr. –Ing.
BECHET PAUL

AUTHOR
Stud. Sg.
ROMANIUC
ALEXANDRU -GABRIEL

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-HAMBURG, 2019 –

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,,Nicolae Balcescu,, Land Forces Academy

BACHELOR THESIS

THEMA:
,,Near Field Beamforming for Colocated
MIMO Radar ’’

SUPERVISORS
PD Dr. –Ing.
THOMAS FICKENSCHER
Col. Prof. -Univ. Dr. –Ing.
BECHET PAUL

AUTHOR
Stud. Sg.
ROMANIUC
ALEXANDRU -GABRIEL

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REFERAT DE APRECIERE
a lucrării de licență

1. Numele și prenumele absolvent: [anonimizat]:

2. Domeniul de studii:

3. Programul de studii universitare de licență:

4. Tema lucrării de licență:

5. Aprecieri asupra conținutului teoretic al lucrării de licență (se
marchează cu X):
Criterii Nivel de îndeplinire a
criteriului minim mediu ridicat excelent
Identificarea stadiului actual al
cercetării în domeniu
Capacitatea de sinteză și construcția
logică a argumentației teoretice
Gradul de relevanță a conținutului
teoretic în raport cu tema lucrării
Capacitatea de operare cu concepte și
teorii specifice
Gradul de relevanță și
actualitatea bibliografiei
Citarea corectă a ideilor și a
conceptelor preluate din alți autori,
evitarea plagiatului conform declarației pe
propria răspundere a
autorului lucrării

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6. Aprecieri asupra părții practic -aplicative a lucrării de licență (se
marchează cu X):
Criterii Nivel de îndeplinire a
criteriului minim mediu ridicat excelent
Caracterul logic al organizării
demersului practic -aplicativ
Formularea corectă a obiectivelor
Calitatea metodelor și
instrumentelor de lucru,
corectitudinea utilizării acestora
Pertinența concluziilor și a
propunerilor formulate de autor,
derivarea logică a acestora din
studiul realizat
Originalitatea abordării, contribuții
personale ale autorului

7. Aprecieri privind redactarea lucrării de licență:

Criterii Nivel de îndeplinire a
criteriului minim mediu ridicat excelent
Corectitudinea și claritatea
exprimării, utilizarea limbajului de
specialitate
Calitatea grafică a lucrării
Respectarea exigențelor de
redactare conform Ghidului
metodologic

8. Considerații finale:

Apreciez lucrarea de licență cu nota _____________ și o recomand
pentru a fi susținută în prezența comisiei examenului de licență.

Data Conducător științific

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Table of contents

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Introduction
Nowadays, the radar is an instrument, a device of great interest in the
scientific community, and has been studied since more than 100 years ago . The
radar has found applications in many areas such a s traffic control, meteorology
monitoring and many other areas . In particular, radar systems have been and
are used in military and civilian areas due to their performance and utility. Its
practical applications have had a great impact on daily life because this
systems are used by polic e, air traffic, ships, airplanes and so on . The rapid
development and research of the radar has made this system very efficient and
accurate , but the research in this area continues to make p rogress .
The RADAR acronym comes from RAdio Detection And Ranging when
for the first time was called RDF by the British and then was renamed as
RADAR by the Americans in 1940 . A special type of the radar is the MIMO
Radar, whose acronym comes from Multiple -Input Multiple -Output.
This type of radar involves the use of a different number of receptors (Rx) and
transmitters (Tx) built in the form of an array. One important thing about
MIMO Radar is the fact that the re is an independence about the signals of
elements that can be individually configured. For example, the power
transmitted by each element or the duration of the transmitted waveform.
The transmitter array and receiving array can be configured with a dif ferent
elements spacing which can provide a different aspect and analyzation of the
target . By using this system we can determine some important parameters
about targets such as: speed, range, bearing and direction of arrival.
The operation o f the radars is quite simple, each transmission element
radiates power in a certain direction in space. An important observation in this
case is that the total radiated power is independent by the number of
elements. The radiated power will be reflected by the targets. Each target is
characterized by its RCS function . This RCS parameter represents the amount
of energy which is effectively radiated in all di rection by the targets . Of course,
there are many interferences during the propagation of the signals to the
target and from the target to the receiver array. These interferences can be
constructive but also destructive in terms of signal integrity. In the case of
interferences that may occur during signal propagation, we can list a few:
multipath interfer ence, reflection and refraction phenomenon, diffraction of
wave, sea clutter, wind turbines, metal buildings, trees and leaves, electrical
wires.

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In this thesis, we will simulate the behavior of an array with specified
parameters under certain di fferent conditions. Regarding this array, we will
consider a specific type of array, namely an ULA. This acronym of array comes
from Uniform Linear Array, which involves using a number of linearly
distributed sensors at the same distance. Each element will have the same
amplitude and will operate on the same frequency. The advantage of using this
type of array is that it allows changing the pattern by making the array more
directive and thus increasing the gain. We can also adjust the excitement of
each element to obtain a phased array that allows a scan of a space
Then we will integrate two matrices of this type to simulate a radar that works
in the MIMO configuration. As mentioned above, we will need two arrays to
simulate this radar, a transmitter arra y, and another array for the receivers.

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Fig(1.1) Uniform Liniar Array Position in three dimentional coordinates

For our initial discussion, I considered an ULA( Uniform Liniar Array) consist of 8
elements of Receiver am one element of Transmitter. The position of each elements is
drawing in Fig(1.1) with an elements spacing of 0.5m. The transmitter position is in the
origin of this three dimensional axis. For this phased array parameters, we defined the
carrier frequency as 13.5MHz. For the next step, we defined a single target in a specified
region with the following coordinates (5.0020, 1201.6, .755) meters and minimum target
radar cross section (RCS) as 1 square meters .

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Figure(1.2) Time domain representation of transmit pulse

Figure(1.2) Frequency domain representation of transmit pulse
The transmit pulse is used as transmit wave for our transmitter and, it has the frequency of
13.5MHz

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Figure( 1.3) Polar plot for radia tion pattern, angles=0, 30, 45 degrees

Figure( 1.4) Normalized array factor, angles =0, 30, 45 degrees

Figure( 1.5) Polar plot for radiation pattern, angles=90, 135, 150 degrees

Figure( 1.6) Normalized array factor, angles=90, 135, 150 degrees

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Figure( 1.6) Normalized Radiation Pattern for near -field and far -field point source, 8Rx and
d/lambda=0.5, carrier frequency=13.5Mhz
In the figure above, is representing the Beam Pattern for a specified point source in the
near -field region or ,,Fresnel region,, but considerind the distance df = 2D2∕λ from the source
and, a point source in the far -field with these two conditions : df >>D, df >> λ.

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Figure( 1.6) Influcences of one target in the far -field at approximately 38000m, at angle
theta=30 degrees and -15 degrees

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Figure( 1.6) Target position estimation using range -Doppler resolution

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