TELKOM
NIKA
, Vol.14, No
.2, June 20
16
, pp. 555~5
6
2
ISSN: 1693-6
930,
accredited
A
by DIKTI, De
cree No: 58/DIK
T
I/Kep/2013
DOI
:
10.12928/TELKOMNIKA.v14i1.3291
555
Re
cei
v
ed
De
cem
ber 1
8
, 2015; Re
vi
sed
March 25, 20
16; Accepted
April 13, 201
6
Measur
e
ment and Evaluation of Tx/ Rx Antennas for
X-Band Radar System
Folin Oktafiani
1*
, Yu
y
u
Wah
y
u
1
, Yusuf Nur Wija
y
a
nto
1,2
1
Indones
ia
n Institute of Scien
c
es (LIPI), Jl.
Sangk
uria
ng, Ci
situ, Bandu
ng
401
35 INDON
ESIA,
T
e
lp. +
62-22-2
50-4
660 F
a
x. +
62-2
2
-25
0
-4
66
0
2
Nation
al Institute of Information an
d
Comm
unic
a
tions T
e
chno
log
y
(NICT
)
,
4-2-1 N
u
kui-K
i
tamach
i, Koga
n
e
i, T
o
ky
o 184-
879
5 JAPAN
*Corres
p
o
ndi
n
g
author, e-ma
i
l
: folin.okt
afia
ni
@lip
i.go.i
d
, oktafian
i@gm
ail.c
o
m
A
b
st
r
a
ct
T
h
is p
aper
pr
esents th
e
per
forma
n
ce
ev
al
uatio
n
of a
n
te
nnas
for
micr
o
w
ave trans
mis
s
ion
an
d
recepti
on
in X-
ban
d ra
dar sy
stems. T
h
e
tra
n
smitter
(T
x) a
nd rec
e
iv
er (R
x) ante
nnas
ar
e fabric
ated
o
n
micr
ostrip
arra
y structures. T
he
ante
nnas
a
r
e co
nnect
ed t
o
microw
av
e c
i
rcuits w
i
th tra
n
smissio
n
lin
e
s
,
coaxi
a
l ca
bl
es, and
microw
a
v
e co
mb
iners
and s
p
litte
rs. T
he
des
ig
ned
anten
nas in
X
-
ban
d microw
a
v
e
oper
ation for T
x
and Rx part
s
w
e
re
fabricated id
entica
lly
by
4x64
micro
s
trip patch ant
enn
as in an ar
ray
structure. T
he fabricate
d
ant
e
nnas w
e
re
me
asure
d
for return loss (S
11)
, VSW
R, radia
t
ion p
a
ttern, a
n
d
Gain. T
he d
e
tail
meth
ods fo
r the meas
ure
m
e
n
ts are r
e
p
o
rted a
nd th
eir
results are
al
so disc
ussed.
T
h
e
me
asur
ed a
n
te
nna g
a
i
n
of ~
20dBi, an
d be
a
m
w
i
dth of
~
20de
gree c
an b
e
obtai
ne
d usi
ng the fabr
icat
ed
anten
nas at 9.
4GH
z
micr
ow
ave oper
atio
n.
Ke
y
w
ords
: Microstrip ante
n
n
a
s, array struct
ure, radar syst
em, X-b
and
mi
crow
ave
Copy
right
©
2016 Un
ive
r
sita
s Ah
mad
Dah
l
an
. All rig
h
t
s r
ese
rved
.
1. Introduc
tion
Rad
a
r i
s
a d
e
vice that ca
n be u
s
ed to
monitor the
waters, air
and lan
d
. Th
ere a
r
e
variou
s ki
nd
s of techn
o
log
y
that can
b
e
used
in
ra
dar
sy
st
em
s,
su
ch a
s
F
M
CW t
e
ch
nolo
g
y
,
Pulse, Pulse Comp
re
ssion
etc. Each technol
o
g
y has
advantag
es a
nd disadvant
age
s [1-5].
Rad
a
r sy
ste
m
which de
si
gned in this
pape
r uses F
M
CW techn
o
l
ogy with the followin
g
con
s
id
eratio
n
s
, usi
ng lo
w
operation a
n
d
mainten
a
n
c
e co
st, usin
g
small p
o
wer t
r
an
smit that
will
redu
ce
cost
s, small
si
ze
[6-8]. But its disadvantag
e, namely t
r
ansmit
and
receive
si
gnal
s
pro
c
e
ssi
ng
cannot u
s
e
a
singl
e ante
n
n
a
, so th
at ne
ed two
ante
n
nas f
o
r
a tra
n
smitter and
a
rec
e
iv
er.
One pa
rt that has an imp
o
rtant role in the
rada
r sy
ste
m
is antenn
a system. Ante
nna is
a
device that u
s
ed to tran
smit and recei
v
e signal
s.
If
the antenna
can tra
n
smit sign
al and re
ceive
reflecte
d
sig
nal from
th
e targ
et by gain
and
radiation
pattern th
at suit
able to
de
si
red
specifications, it will be abl
e to detect the target
preci
s
ely and accurately [9-11]
. Some aspects
that must b
e
co
nsi
dered
in rad
a
r d
e
s
igni
ng a
r
e
operating fre
quen
cy a
s
so
ciated
with t
h
e
appli
c
ation
to
be
used, the
anten
na
gai
n, bea
mwidth
,
target
ran
g
e
,
the resoluti
on of th
e ta
rget
detectio
n
, etc.
Rad
a
r that being de
sign
e
d
is rada
r for nav
igatio
n
applicatio
ns on vessel
s
so that
requi
re
d a compa
c
t ante
nna de
sign t
hat can be i
n
stalle
d on ships, therefore, used X-b
a
nd
freque
ncy in
con
s
id
eratio
n
will minimi
ze the di
me
nsions
of the a
n
tenna [1
2-1
4
]. Additional
ly,
antenn
a syst
em that be desig
ned
shou
ld have a hi
g
h
wind resi
st
ance so that
whe
n
the ant
enna
rada
r rotate
s
at a spee
d of 6, 7, 8,
9, 10
rpm, anten
na
rotates n
o
rm
ally.
Another facto
r
that
determ
i
nes ante
nna
perfo
rma
n
ce
is i
s
ol
ation
betwe
en tran
smitter
and receiver antenna. Isolation effect
that
happe
ns in the
radar i
n
fluen
ce
s RF
circuit
perfo
rman
ce
greatly, n
a
me
ly pro
c
e
s
sing
for i
n
coming
sig
nal i
n
to th
e receiver. I
s
olation
effect
is
cau
s
e
d
by a
n
tenna m
u
tu
al co
upling t
hat mut
ually
influen
ce o
ne an
other
(transmitter a
nd
receiver). So that leaked
power
that received by rece
iver from transmitter
will be assum
ed
as
obje
c
t in re
ce
iver then will
be displayed
at rada
r di
spl
a
y. The meth
od that be u
s
ed to increa
se
antenn
a i
s
ola
t
ion is addi
ng
air
gap
bet
ween tran
smi
tter a
nd
re
ceiv
er a
n
tenn
a. B
y
addin
g
ai
r g
ap
incr
ea
se
s win
d
resi
st
an
ce,
t
oo.
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 16
93-6
930
TELKOM
NIKA
Vol. 14, No. 2, June 20
16 : 555 – 56
2
556
Antenna typ
e
that use
d
is micro
s
tri
p
ant
enn
a
, becau
se it has
small di
mensi
on,
lightwei
ght, ease to fab
r
icate and lo
w
co
st. One of
microstri
p
we
akn
e
ss is it h
a
s lo
w gai
n, so
that to increa
se its gai
n then de
sign
ed
array microstrip antenn
a [15-20].
In orde
r to se
e perfo
rman
ce of antenna
syst
em that h
a
s be
en de
si
gned, ante
n
n
a
must
be mea
s
u
r
ed
in the labo
ratory and th
e field.
Base
d on that, we rep
o
rt the
measureme
n
t
method
s a
n
d
discu
s
s its result
s in
this pap
er.
T
he
cha
r
a
c
teri
stics of th
e a
n
te
nna
syste
m
are
measured su
ch a
s
the re
turn lo
ss, ga
in, radiat
io
n pattern, an
d
isolatio
n to make
su
re t
hat
antenn
a ha
s desi
gne
d at desired fre
que
ncy ope
ration
.
2. Ante
nna S
y
stem
2.1. Whole Struc
ture
Figure
1
(
a
)
shows stru
ctu
r
e
of
rad
a
r an
tenna syste
m
.
It
is comp
o
s
ed
of seve
ral
pa
rts
su
ch
as Tx/Rx antenn
as,
a
n
tenna
fram
e
,
rado
me
, tilting me
ch
ani
s
m, gea
r
box,
and m
odul
e b
o
x.
The Tx/Rx
antenn
as are arra
nge
d
by mountin
g
on th
e fra
m
e an
d by
locking
on
tilting
mech
ani
sm
with elbo
w. The tilting mech
ani
sm ha
s a fun
c
tion
to adjust an
g
l
e of the vertical
dire
ction of th
e antenn
a. It
can b
e
used t
o
obtain
opti
m
um dista
n
ce ran
ge of the rad
a
r. The
shift
angle of tilting mech
ani
sm
is 10 deg
ree
towards the t
op and b
o
ttom.
(a)
(b)
Figure 1. (a)
Structu
r
e of the rad
a
r a
n
te
nna sy
stem in whol
e-vie
w
, and (b
) Structure of the
antenn
a for T
x
and Rx part
s
The rad
a
r ant
enna
sy
stem mainly
con
s
ists
of
Tx a
nd
Rx ante
nna
s
as
sh
own in
Fig. 1(b
)
They are lo
cated in the same pla
c
e a
nd rotate
tog
e
ther. They a
r
e se
pa
rated
by an air gap
to
minimize mut
ual couplin
g
effects a
nd
wind re
si
st
an
ce. The Tx an
d Rx ante
nna
s are ide
n
tica
lly
same
stru
cture includ
e the sha
pe and
si
ze. The
Tx/Rx antennas a
r
e comp
osed
of eight anten
na
module
s
a
r
e
arrang
ed ho
ri
zontally. In a
one ante
nna
module h
a
s 4
x 8 antenna array.
In
ord
e
r
to protect
the ant
enna syste
m
from
un
wa
nted
weathe
r condition su
ch
as high
heat or
heav
y raining, a
radome
mad
e
from fibe
r m
a
terial i
s
u
s
e
d
to cove
r th
e anten
na
system.
The ra
dom
e has a
ch
ara
c
t
e
risti
c
ba
si
cal
l
y as an in
sul
a
tor. As a result, it has no
affection to th
e
antenn
a sy
stem pe
rform
a
nce. T
he d
e
s
ign
ed
rado
me
cons
is
t
s
of two parts
to protec
t the Tx
antenn
a in the uppe
r sid
e
and the Rx a
n
tenna in the
bottom side.
(a)
(b)
Figure 2. (a)
Structu
r
e of the motor fo
r rota
ting anten
nas to direct
beam
-ste
erin
g, and (b
)
Structu
r
e of the modul
e bo
xes to locate
the electroni
c
RF modul
e
s
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
1693-6
930
Measu
r
em
en
t and Evaluati
on of Tx/ Rx Antenna
s
for
X-Band Rada
r System
(Fol
in Oktafiani
)
557
In orde
r to control the b
e
a
mformin
g
of
the antenn
a
s
, a motor i
s
used to
rot
a
te the
antenn
a
syst
ems i
n
3
60
d
egre
e
s in
azi
m
uth di
re
ctio
n.
Illustratio
n
of the moto
r i
s
sho
w
n
in Fi
gure
2(a
)
. By usin
g the mecha
n
ically be
amf
o
rmin
g, targe
t
s in 360 d
e
g
r
ee
s in a
z
imu
t
h dire
ction can
be scan
ned.
Since the Tx and Rx ante
n
nas a
r
e
s
epa
rated by the
air gap, the a
n
tenna
syste
m
become
s
lig
h
t
and l
o
w wi
n
d
resi
stan
ce.
The
r
efo
r
e,
t
h
e m
o
tor
ope
r
ates
smoothl
y
with lo
w l
o
ad
and lo
w po
we
r con
s
u
m
ptio
n.
In the ra
da
r
system
anten
na, RF
ci
rcuits for f
r
ont-en
d
pa
rts a
r
e
al
so in
stalle
d. The
RF
circuits
such as
a high po
wer
amplifie
r circuit
bef
ore
the Tx anten
n
a an
d a lo
w noise am
plifier
circuit after the Rx antenna
. The RF circuits are a
r
ran
ged in a mod
u
le boxes tha
t
is conne
c
te
d
to the antenn
a system u
s
i
ng a rotary jo
int. The pos
iti
on of module
boxes in this rada
r as sho
w
n
in Fig. 2(b) i
s
clo
s
e to the a
n
tenna
syste
m
to minimize microwave loss of the system.
2.2. Tx/ Rx Antenn
as
The Tx/Rx ra
dar a
n
tenn
a i
s
compo
s
e
d
of ei
ght
mod
u
les are arra
nged hori
zo
n
t
ally
as
sho
w
n in
Fig
u
re 3. In a
singl
e mod
u
l
e
, there a
r
e
four rows of
sub
-
mo
dule
whi
c
h form
the
arrang
ement
of the eight patch
es
ho
ri
zontally, so in a single mo
dule there are 32 pieces
of
patch
es.
The
dimen
s
io
n of
the a
n
tenn
a
module
s
are 188.98m
m
in
length
an
d width 22.25m
m
.
Picture
of the
fabri
c
ated
of total antenn
as fo
r Tx
o
r
Rx pa
rts i
s
shown in Fi
gu
rre
3(a), a
nd
the
picture of
a
single
antenn
a
modul
e i
n
f
r
ont a
nd
ba
ck vie
w
respe
c
tively ca
n b
e
seen
in Fi
g
u
re
3(b
)
an
d 3
(
c). Figure 3
(
c) shows that the
antenn
a mo
dule con
s
i
s
ts of
four
in
se
rt port
that serv
e
s
as th
e fe
edin
g
for ea
ch
sub-m
odul
e. T
he fee
d
ing
is don
e by
coa
x
ial probe
fe
eding
techniq
u
e
whi
c
h fe
edin
g
p
r
o
c
ess is
start from th
e
anten
na
gro
und
plan
e a
n
d
then
pe
netrate through
t
h
e
sub
s
trate to
conne
ct the
an
tenna pat
ch o
n
the top.
(a)
(b)
(c
)
Figure 3. Picture of the fab
r
icate
d
anten
nas (a) to
tal a
n
tenna
s for T
x
or Rx parts,
(b) fro
n
t view
of the antenn
as, and
(c) ba
ck vie
w
of the antenna
s
Figure 4. De
sign and p
a
ra
meters of the fabricated ant
enna
sub
-
mo
dule
Antenna mo
d
u
le is arra
nge
d in an array stru
ctur
e into a hori
z
ontal d
i
rectio
n to ge
nerat
e
high gai
n an
d narro
w bea
mwidth corre
s
po
ndin
g
to
the de
sire
d specifi
c
ation
s
.
Tx/ Rx antenna
has the
overall len
g
th 1
5
11.68mm
an
d wi
dth 8
9
m
m
. Th
e pi
ctu
r
e
of the
arra
ngeme
nt of
e
i
ght
antenn
a mod
u
le whi
c
h i
s
the Tx/Rx antenna
system
can b
e
se
en i
n
Figure 3(a
)
.
The pat
ch
an
tenna i
s
u
s
ed
with a
squ
a
re-shap
ed
wh
ere the
si
ze
set to 8.75 x 8
.
75mm
2
.
The
Tx/Rx ra
dar anten
na system
i
s
array
that
co
ns
i
s
ts of
64 patches
ho
rizonta
lly and 4
pat
ches
vertically. Distance b
e
twe
en ea
ch ho
ri
zontal p
a
tch
is 14.75m
m while e
a
ch v
e
rtical p
a
tch
is
14.25mm.
The de
sig
n
o
f
the 1 x 8 patch a
n
tenn
a
s
is
sh
own i
n
Figu
re 4. T
h
e tran
smi
s
si
on line
con
n
e
c
ts inte
r the a
n
tenn
a
patch i
n
a
su
b-mo
dule
wi
t
h
si
ze of
3.4
mm in len
g
th. It has a
pha
se of
80ra
d
and
a width of
0.8
mm
to pro
d
u
c
e 70.71
ohm
impe
dan
ce. The
fe
edin
g
cha
r
a
c
teri
stic
h
a
s
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 16
93-6
930
TELKOM
NIKA
Vol. 14, No. 2, June 20
16 : 555 – 56
2
558
impeda
nce of
50oh
m. In order to
obtain
matchin
g
con
d
ition, the im
peda
nce adj
u
stment i
s
ad
d
ed
by locating
su
b-mo
dule
s
wi
th a length of 3.
4 mm and a
width of 1.2mm in the middle.
The ante
nna
module
s
a
r
e
arrang
ed in a
rray to e
nhan
ce its
perfo
r
m
ances. Th
e m
o
dul
e
s
are
co
nne
cte
d
togeth
e
r to
main
input
o
r
o
u
tput
si
gn
als. It can
be
re
alize
d
u
s
in
g po
we
r divid
e
r/
combi
n
e
r
wit
h
4:1 an
d 8:
1 [21-2
3
]. Power
divide
r/combine
r
4:1
c
onsi
s
ts
of fou
r
input
s an
d
one
output on the
receiver
sid
e
, and on
e in
put and fou
r
outputs
on th
e tran
smitter
side. Thi
s
al
so
applie
d to the
po
wer divide
r/com
b
ine
r
8:
1. Semi-rigid
cabl
es are u
s
ed a
s
a
lin
k b
e
twee
n feedi
n
g
and in/ out
power
combi
ners. Selecti
on of the
ap
prop
riate
co
mbine
r
ca
n minimize the
loss
gene
rated
in
the
pro
c
e
s
s of
divide/
combine
a
n
te
nna
mod
u
les. If the me
rger
of
feedi
ng
perfo
rmed o
n
the hori
z
ont
al side first then ne
ede
d
four po
we
r di
viders/
com
b
i
n
ers 8:1 so the
semi
-rigi
d ca
ble to be use
d
much lo
ng
er and m
u
ch more that will
incre
a
se the
loss. When t
h
e
use
d
semi-rig
id ca
ble
s
are
not in the
sa
me length,
it
will produ
c
e
a
different ph
a
s
e a
nd
will affect
to perform
an
ce of the ant
enna
system.
Based on th
i
s
co
nsi
deration, the merg
ers a
r
e d
one
per
module
by co
nne
cting ea
ch feeding
on
a su
b mod
u
le
. The dista
n
ce between th
e semi
-ri
gid
must
be co
nsta
nt becau
se it wi
ll lead to the pha
se di
ffere
nce of the an
tenna. To ke
ep the dista
n
c
e
betwe
en
the
semi
-rigi
d ca
bles
is used material as
s
hown in
Fig.
5(a
)
in
re
d lin
e. Co
nfiguration of
the po
we
r div
i
der/
com
b
ine
r
in th
e a
n
ten
na
system
s
can b
e
seen
i
n
Figu
re
5(b). The o
u
tput
of
the power
divider/co
m
bin
e
r 4:1 the
n
combi
ned
wit
h
the po
we
r divider/com
biner
8:1 to
be
c
o
nn
ec
te
d
to
th
e
ma
in
s
i
gna
l s
o
ur
ce
.
(a)
(b)
Figure 5. (a)
Typical in
stall
a
tion of the powe
r
co
mbin
er/ splitter in t
h
e anten
na system, and
(b)
Config
urat
ion of the po
wer
com
b
in
e
r
/ splitter in the antenn
a sy
stem
s.
3. Experiment
3.1. Retu
rn L
o
ss
Vector
Network An
alyze
r
(VNA) wa
s
use
d
to mea
s
ure the retu
rn loss an
d VSWR.
Figure 6
sho
w
s th
e me
asured
retu
rn l
o
ss an
d VS
WR
re
sult
s o
f
the fabri
c
at
ed ante
nna
su
b
module
s
. Th
e result sho
w
s the anten
n
a
has g
ood
return lo
ss at
desi
r
ed frequ
ency at 9.4G
Hz.
Figure 6(b) shows the me
asu
r
ed VS
WR of t
he fab
r
icate
d
ante
n
na whi
c
h h
a
s
an op
eration
freque
ncy
of 9.356-9.517
G
H
z
with VS
WR value
s
of
l
e
ss than
1.5.
The m
e
a
s
ured ba
nd
width
of
161M
Hz wa
s obtaine
d. Ba
sed
on the
m
easure
m
ent
result
s, the fa
bricated a
n
te
nna
s have
go
od
agre
e
me
nt wi
th the desig
n spe
c
ification.
(a) Retur
n
Lo
ss
(b) VSW
R
Figure 6. The
measu
r
em
en
t of an antenn
a sub mo
dule
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Measu
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em
en
t and Evaluati
on of Tx/ Rx Antenna
s for
X-Band Rada
r System
(Fol
in Oktafiani
)
559
(a) Retur
n
Lo
ss
(a) VSWR
Figure 7. The
measu
r
em
en
t of a single a
n
tenna mo
dul
e
Measurement
of the combi
ned fou
r
sub
-
modul
e
anten
nas
usi
ng p
o
w
er divide
r/combine
r
is also necessary to en
su
re the combi
n
e pro
c
e
ss d
o
e
s not affect
the value of return lo
ss a
n
d
VSWR. The
measurement
results of return lo
ss an
d VSWR of the
antenna
mo
dule
s
are sho
w
n
in Figure 7. We can see that t
he measurem
ent re
sul
t
s co
rre
sp
ond
to the design
ed sp
ecifi
c
ati
on.
3.2. Gain
There a
r
e two type of gai
n mea
s
u
r
em
ent me
thod,
absolute a
n
d
com
pari
s
o
n
method.
The
com
pari
s
on meth
od
n
eed
s a
refe
re
nce
ante
nna
with a
ce
rtain
gain. T
he
an
tenna
s a
r
e
often
use
d
as a ref
e
ren
c
e i
s
a dipole anten
na
λ
/ 2 and a horn anten
na. A gain antenn
a
measu
r
em
en
t
perfo
rmed i
n
this stu
d
y usi
ng the
comp
arative meth
o
d
. A horn
ant
enna i
s
u
s
ed
as a
refe
ren
c
e
antenn
a. Port
1
of the Si
g
nal G
ene
rato
r i
s
con
n
e
c
te
d to th
e a
n
te
nna
so
urce
a
s
a
T
r
an
smitter
(Tx) and po
rt
2 on the Sp
ectru
m
Analyzer i
s
con
n
e
c
ted to the antenna to be m
easure
d
(AUT)
and the
reference anten
n
a
that acts
a
s
a receiv
er (Rx). In the compa
r
ison m
e
thod, the po
we
r
received
by the AUT a
nd
a refere
nce a
n
tenna
are
compa
r
ed.
Th
e minim
u
m di
stan
ce
of far
field
betwe
en the tran
smitting a
n
tenna a
nd th
e rece
iving a
n
tenna i
s
exp
r
esse
d as foll
ows:
=
(
1
)
Whe
r
e,
is the minimum
distan
ce bet
wee
n
transmi
tter and recei
v
er (cm
)
,
is the largest
dimen
s
ion of
the antenn
a (cm), an
d
is the microwave wavele
ngth
(cm
)
.
The m
e
a
s
ure
m
ent result o
f
gain a
n
tenn
a is
sh
own in
Table
1. Th
e mea
s
u
r
em
ent wa
s
done by
co
mpari
ng the
maximum re
ceive po
we
r
of antenna
u
nder te
st wit
h
the maxim
u
m
receive po
wer of antenn
a referen
c
e
[24, 25
]. The measurem
ent usin
g ho
rn anten
na
as a
referen
c
e
ant
enna
with
a f
r
equ
en
cy of
9.4GHz
ha
s
9dBi gai
n,
so
that the
me
asu
r
em
ent g
a
in
antenn
a und
e
r
test ca
n be
cal
c
ulate
d
by the equatio
n:
(
2
)
Whe
r
e, Pa is the maximum receive po
wer
of anten
na und
er te
st, Ps is the maximum re
cei
v
e
power of ante
nna refe
re
nce, and Gs i
s
the gain of ant
enna referen
c
e.
Table 1. The
Gain mea
s
u
r
ement re
sult
of antenna m
odule
No
The Ma
ximum re
ceive pow
er
of A
U
T (dBm
)
The Ma
ximum re
ceive pow
er
of re
ference (dBm
1. -36.25
-47.27
2. -36.46
-46.01
3. -36.12
-47.38
4. -35.31
-47.81
5. -36.11
-46.68
6. -36.02
-47.25
7. -36.54
-47.05
8. -36.61
-48.22
9. -35.27
-47.19
10. -36.43
-47.06
Average
-36.112
-47.192
Gain
dBi)
20.08
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Vol. 14, No. 2, June 20
16 : 555 – 56
2
560
In ord
e
r to o
b
tain a
c
curate re
sult
s, the
mea
s
u
r
eme
n
t of the
re
ceive po
we
r d
one f
o
r
several times. Then the av
erag
e value
s
of each re
cei
v
e powe
r
at t
he anten
na u
nder te
st an
d
a
referen
c
e ant
enna
wa
s taken. Fu
rthe
rmore the
averag
e value
can b
e
cal
c
u
l
ated for gai
n of
antenn
a und
e
r
test. The m
easure
d
gain
of a single a
n
t
enna mod
u
le
is 20.08dBi.
3.3. Radiato
n
Patern
Antenna
radi
ation pattern
is a pi
cture
of
antenn
a
beam inte
n
s
ity as a fu
nction
of
sph
e
ri
cal coo
r
dinat
e
s
(
Φ
,
θ
). The
radi
ation patte
rn i
s
obtaine
d
by
makin
g
the
p
a
ttern of el
evation
(
Φ
fixed, variable
θ
) o
r
a
z
imuth patte
rn (
Φ
variabl
e, fixed
θ
).
On the mea
s
ureme
n
t of
the
radiatio
n pattern, a horn antenn
a and
antenna un
der test were use
d
as a
transmitter
an
d
receiver, re
sp
ectively. The transmitting antenna wa
s
conne
cted to the sign
al gen
erato
r
and th
e
receiver a
n
te
nna was
con
necte
d to the
spe
c
trum
an
alyzer [2
6, 27]. To get the azim
uth an
d
elevation ra
di
ation pattern,
the r
ada
r ant
enna
wa
s rot
a
ted 360 d
e
g
r
ee
s.
Measurement
results fo
r the ra
diation
patte
rn of th
e fabri
c
ated
antenn
a mod
u
le a
r
e
sho
w
n in Fi
g
u
re 8. Figu
re
8(a
)
is the m
easure
d
ra
di
ation pattern
in the azim
uth with bea
m
w
idth
of 10 degree
s at -3dB. Fi
gure 8
(
b
)
is
the measur
e
d
radiatio
n p
a
ttern in the
elevation wi
th
beam
width of
20 degree at
-3dB.
The anten
na
module of the
first gene
rati
on ant
en
na system has a
n
elevation be
amwidth
of 20
˚
, this value is obtai
n
ed by the addition of re
fle
c
tors so that
the antenna
radiation patte
rn
can b
e
focu
ssed o
n
a pa
rticula
r
be
am
width
an
gle. The elevatio
n beam
width
of an anten
na
module
on
a
se
con
d
-g
ene
ration rada
r a
n
tenna
sy
ste
m
is th
e
sam
e
a
s
the
first
gene
ration.
T
h
is
prove
s
that
a verti
c
al a
n
t
enna
array
can
re
du
ce
an el
evation
beam
width
without
usi
n
g
the
reflec
tor.
(a)
(b)
Figure 8. The
Measu
r
em
en
t result
of radi
ation patern a
n
tenna mo
dul
e
4. Analy
s
is
4.1. Gain
The gain m
e
asu
r
em
ent re
sults of the
antenn
a mod
u
le is 20.08
dB, this was due to
arrang
e the
a
n
tenna
array
can
imp
r
ove t
he a
n
tenn
a g
a
in. Antenn
a
array will
affe
ct the
numb
e
r
of radi
ating
element
s a
n
d
ape
rtur
e a
n
tenna
s. Th
e
more ele
m
e
n
ts a
r
e
used
so th
e radia
t
ion
emitted will a
l
so in
crea
se.
The ante
nna
gain i
s
di
rectl
y
propo
rtion
a
l
to the anten
na ap
ertu
re a
s
an eq
uation
o
f
antenn
a gai
n. The
array
stru
cture ma
ke
s
gre
a
ter
effective ap
ertu
re that will
affe
ct
the antenn
a g
a
in,
A
e
and
(3)
Whe
r
e, D i
s
the dire
ctivity,
G is t
he gain,
Ae is the effective apertu
re
, and
η
is
the Effic
i
enc
y.
Gain a
n
tenn
a is n
eede
d
in the sy
ste
m
rad
a
r d
e
p
end
s on th
e
power u
s
e
d
. On ra
da
r
system
s
with
FMCW techn
o
logy that u
s
es p
o
wer
i
s
relatively smal
l at about 2
watts re
quire hi
gh
gain in
ord
e
r
to rea
c
h
a di
stant target
with go
od sh
arpn
ess re
sol
u
tion.
To
b
e
able
to rea
c
h
the
target with
a
distan
ce
of
9
-
10 NM with a
ra
da
r ante
n
na h
e
ight of
15m i
s
n
eed
ed g
a
in of
30
dB.
To o
b
tain a
n
antenn
a g
a
in
of 30
db i
s
ne
ce
ssary
to
do
the a
r
rang
e
m
ent of th
e a
n
tenna
mod
u
l
e
s
so the Tx/Rx rada
r ante
n
n
a
is co
mpo
s
e
d
of eight module
s
are a
r
range
d hori
z
o
n
tally.
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TELKOM
NIKA
ISSN:
1693-6
930
Measu
r
em
en
t and Evaluati
on of Tx/ Rx Antenna
s for
X-Band Rada
r System
(Fol
in Oktafiani
)
561
4.2. Beam-
w
i
d
th
Figure 9 sho
w
s radiatio
n pattern shap
e for 8
uniform array elem
ents. Being g
r
eate
r
the
distan
ce of e
a
ch el
ement, then the mai
n
lobe
be
com
e
s na
rrower
and si
de lobe
becom
es m
o
re.
At antenna
desi
gn u
s
e
s
0.5
λ
for it
s
distan
ce i
s
ol
ation to get
narro
w main
lobe an
d fe
wer
sidel
obe. T
h
e na
rro
w
be
amwidth
is
required fo
r
radar ante
n
n
a
in o
r
d
e
r to
get lon
g
ra
nge
detectio
n
. To
increa
se m
a
ximum dete
c
ti
on ra
nge
ca
p
abilities, the
e
nergy i
s
con
c
entrated i
n
to
as
narro
w a
bea
m as is fea
s
i
b
le. Becau
s
e
of practi
ca
l
con
s
id
eratio
n
s
related
to t
a
rget
dete
c
tion
only the hori
z
ontal beam
width is quite n
a
rrow
, typical
values bei
ng
betwee
n
abo
ut 0.65
˚
to 2.0
˚
.
The vertical b
eam width i
s
relatively br
o
ad, typical values b
e
ing b
e
twee
n abo
ut 15
˚
to 30
˚
.
Figure 9. Arra
y factor and a
ngula
r
pattern of 8-elem
en
t uniform arra
y
To get
na
rro
w h
o
ri
zontal
beam
width fo
r Tx/R
x a
n
te
nna,
so
at a
n
tenna
de
sig
n
u
s
e
s
8
array antenn
as ho
rizontall
y
. Measurem
ent
result sho
w
s h
o
ri
zontal
beam
width is
1
˚
.
5. Conclusio
n
We h
a
ve re
ported
and
pre
s
ente
d
th
e perfo
rma
n
c
e evalu
a
tio
n
of antenn
as for
microwave transmi
ssion a
nd re
ceptio
n in X-
band ra
dar sy
stem
s. The Tx and Rx antenna
s
are
fabricated
o
n
micro
s
trip
array struct
ure
s
. The
d
e
sig
ned
ant
enna
s in X
-
band
micro
w
ave
operation fo
r Tx and
Rx
parts were
fabri
c
ated
id
e
n
tically by m
i
cro
s
tri
p
a
rra
y stru
cture.
The
measurement
method
s an
d re
sults
we
re discu
s
sed i
n
detail. The
measured a
n
tenna
gain
of
~20
d
Bi, and
beam
width
of ~2
0 de
gre
e
can
b
e
o
b
t
ained
usin
g
the fab
r
icated a
n
tenna
s at
9.4GHz microwave
op
eration.
Th
e a
n
tenna
s
ca
n
be
u
s
ed
to X-b
and
ra
dar
sy
stem
for
surveill
an
ce
appli
c
ation
s
. Furthe
rmo
r
e,
the propo
se
d antenn
as can be u
s
ed for future rem
o
te
unit in the ra
dar n
e
two
r
ks
by combi
n
ing
with opt
ical netwo
rks.
Th
erefo
r
e
they can be
conn
e
c
ted
usin
g optical fiber by ado
pting radi
o-over-fiber te
chn
o
l
ogy [28-30].
Referen
ces
[1]
M Skolnik. Ra
d
a
r Han
dbo
ok. T
h
ird Edition. Mc Gra
w
Hi
ll. 2
008.
[2]
YK Ch
an, V
C
Koo.
An
i
n
trod
uction
to sy
nth
e
tic a
pertur
e
r
adar
(SAR).
Pr
ogress
in
El
ectromag
netics
Rese
arch B. 2008; 2: 27-
60.
[3]
YN W
ija
yanto,
A Kanno, H Murata, T Ka
w
a
n
i
shi,
Y Okamura. Millimeter-W
ave Ra
dar Rec
e
iver Usi
n
g
Z
-
Cut LiN
b
O3
Optical Mo
d
u
lator
w
i
th O
r
thogo
nal-G
ap-
Embed
de
d P
a
tch-Anten
nas
on L
o
w
-
k
Dielectric Material.
IEICE T
r
ansactio
n
on El
ectronics
. 20
16
; 98(8): 783-7
9
2
.
[4]
G Richard C
u
rr
y
.
Rad
a
r Es
sentia
ls: A Co
ncise H
and
bo
ok for Rad
a
r Desig
n
an
d P
e
rformanc
e
Anal
ys
is. SciT
ech Pub
lish
i
n
g
Inc. 2012.
[5]
SM Sherma
n,
DK Barton. M
o
nop
ulse
Princ
i
ples
an
d T
e
chniq
ues. 2
nd E
d
itio
n. Nor
w
o
o
d
, MA, USA:
Artech Hous
e. 201
1.
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 16
93-6
930
TELKOM
NIKA
Vol. 14, No. 2, June 20
16 : 555 – 56
2
562
[6]
M Jankiram
an.
Desig
n
of Multi-F
r
equ
enc
y C
W
Radars. USA: Scitech Publ
ishin
g
Inc. 200
7.
[7] AG
Stove.
Mo
dern
F
M
CW
ra
dar - t
e
chn
i
q
u
e
s
an
d a
p
p
licati
ons.
i
n
R
a
d
a
r Confer
ence, 2
004,
E
URAD,
F
i
rst Europea
n
.
2004: 14
9-15
2.
[8]
Hao-Hs
ie
n Ko,
Kai-W
e
n
C
h
e
ng, Hs
uan-J
u
n
g
Su
.
Ran
g
e
r
e
sol
u
tion
i
m
pr
ove
m
e
n
t for F
M
CW
radars.
In Radar C
onfe
r
ence, 20
08, E
u
RA
D 2
008, E
u
rop
ean. 2
008:
352-3
55.
[9]
CA Bala
nis. Moder
n Anten
n
a
Hand
bo
ok. W
ile
y
.
2
018.
[10]
Rob
e
rt J Maillo
ux. Ph
ased Arr
a
y
A
n
tenn
a Ha
ndb
ook. Seco
n
d
Editio
n. Artech Hous
e. 200
5.
[11]
F
Oktafiani, Y
W
a
h
y
u, YS
Amru
llo
h, Y S
aputra, Y
N
W
ija
ya
nto.
An
al
ysis of C
o
rru
gated
Ed
g
e
Variati
ons on
Bala
nced Anti
p
oda
l Vival
d
i An
tennas.
Intern
a
t
iona
l Confer
e
n
ce on Ra
dar, Micro
w
av
e,
Electron
ics, an
d T
e
lecommun
i
catio
n
(ICRAM
E
T
)
2015. Ban
dun
g. 201
5.
[12] Pearce
D.
A h
i
gh res
o
l
u
tion
F
M
CW
X-ban
d r
adar s
ens
or fo
r vessel
un
der
w
a
y reple
n
is
h
m
e
n
t at se
a
app
licati
ons.
In
Radar C
onfer
ence, 20
10 IE
EE. 2010: 64
7-
650.
[13]
M Hajia
n, J Z
ijderve
ld, AA Lestari, LP Ligt
hart.
Analysis, desi
gn an
d measur
e
m
ent of
a series-fed
micr
ostrip arr
a
y anten
na for
X-ban
d I
NDRA
: The Indo
nesi
an
mariti
me ra
dar.
In Proc. 3r
d Eur. Co
nf.
Antenn
as Prop
ag. Berli
n
, German
y
.
200
9: 1
154-
115
7.
[14]
Carus
o
M, Meta A, Corucc
i L, Lom
bar
do
P.
An X-ba
n
d
F
M
CW
rad
a
r for air
ports
'
peri
m
eter
surveillance.
In Radar S
y
mp
o
s
ium (IRS), 2013 14th
Inter
n
a
t
iona
l. 201
3; 2: 853-8
58.
[15]
R Garg, P Bartia, I Bahl, A Ittipib
oon. Microst
r
ip Anten
na D
e
sign H
and
bo
ok
. Nor
w
o
o
d
: Artech Ho
use,
Inc. 2001.
[16] VR
Gupta,
N
Gupta. Ch
arac
teristics of a
Comp
act Micr
ostrip A
n
tenn
a
.
Microw
ave a
nd Optic
a
l
T
e
chno
logy Le
tters
. 2004; 40(
2): 158-1
60.
[17]
R Mishra, P K
u
chhal, A Kumar.
Effect of
Heig
ht of the
Substrat
e a
n
d
W
i
dth of the Patch on th
e
Performanc
e C
haracter
i
stics o
f
Microstrip Antenn
a.
Internati
ona
l Jour
nal
of
Electrical a
nd
Co
mp
uter
Engi
neer
in
g (IJECE).
2015; 5(
6): 1441-
14
45.
[18]
Mashur
y Y W
a
h
y
u, AA Pra
m
udita, P Da
u
d
.
Coup
le
d Pa
tch Array Ante
nna for Surv
eil
l
anc
e Rad
a
r.
T
he Internation
a
l Co
nfere
n
ce
on T
e
lecommu
nicati
on S
y
ste
m
s Services a
nd Ap
plic
atio
n
s
. Bandu
ng.
200
7.
[19]
AF
Morabito,
T
Isernia, L
Di
Don
a
to.
Opti
ma
l
synth
esis of
phas
e-o
n
ly reconfi
gura
b
l
e
line
a
r
sp
arse
arrays
h
a
vin
g
unifor
m
-
a
mpl
i
tude excitatio
n
s
. Progress In E
l
ectroma
gnetic
s Rese
arch. 20
12; 12
4:40
5-
423.
[20]
Muhamm
ad
D
a
rson
o, En
dra
W
ija
ya. C
i
rcul
a
r
l
y
Pol
a
riz
ed P
r
oximit
y-F
ed M
i
crostrip Arr
a
y
Antenn
a fo
r
Micro Satel
lite.
T
E
LKOMNIKA T
e
leco
mmu
n
i
c
ation C
o
mp
uti
ng El
ectronics
and C
ontro
l
. 2
013; 1
1
(4):
803-
810.
[21]
Mike Goli
o.
T
he RF and Micr
o
w
av
e
Han
d
b
o
o
k. Second E
d
i
t
ion. CRC Pres
s. 2008.
[22]
Jong-S
i
k Lim,
Sung-W
o
n L
e
e
, Chu
l
-Soo
Ki
m, J
un-Seok
Park, Dal A
hn,
Sang
w
o
o
k
N
a
m. A 4 : 1
Une
qua
l Wilkin
son Po
w
e
r Divi
der.
IEEE m
i
cr
owave and wireless components letters
. 200
1; 11(3).
[23]
YP Saputer
a,
AB Santiko,
T
aufiqq
u
rrachm
a
n, M W
ahab
.
Desig
n
d
an S
i
mu
lati
on of C
o
mb
in
er/Pow
er
Divid
er 4x
1 M
e
thods
Cav
i
ti
Case for
Ap
pli
c
ation
of LPI
Rad
a
r X-Ba
nd
F
r
eque
ncy.
P
r
ocee
din
g
o
n
Internatio
na
l Confer
ence
o
n
Rad
a
r, Antenn
a,
Micro
w
ave,Electro
n
ics
and T
e
leco
mmunicati
o
n
(ICRAMET
)
. Batam. 2014.
[24]
Hiran
o T
,
Iida
Y, Hirok
a
w
a
J, And
o
M.
Gai
n
meas
ure
m
e
n
t of a
hor
n
ante
nna
by s
horte
n
ed far-fi
e
l
d
techni
qu
e w
i
th
avera
g
in
g.
In A
n
tenn
a Me
asur
ements & A
ppl
i
c
at
ions (
C
AMA
)
, 2014
IEEE C
onfere
n
ce
on. 201
4: 1-3.
[25] HT
Friis.
A Note on a Si
mp
le
T
r
ansmissio
n
F
o
rmu
l
a.
Proc.
of the IRE. 1946; 34(5): 2
54-
256.
[26]
Calaz
ans
T
,
Griffiths HD,
Cull
en
AL, D
a
vies
DEN,
Benj
amin
R
. Antenn
a
r
adi
a
t
ion patter
n
me
asur
e
m
ent
usin
g a n
e
a
r-field w
i
re
scattering tec
hni
que.
In M
i
cro
w
av
es, An
tennas
an
d
Propa
gati
on, IEE Proceed
i
n
g
s
. 1998; 14
5(3)
:.263-26
7.
[27]
Du Z
h
ou, Vi
ika
r
i Vil
l
e, Al
a-
Lau
ri
na
h
o
Juh
a
,
R
a
i
s
an
en
An
tti
V.
2D ante
n
n
a
ra
diati
on patt
e
rn
retri
e
va
l
usin
g reflecti
o
n
coefficie
n
t measur
e
m
ent.
M
i
cro
w
av
e Co
nferenc
e (APMC
)
, 2014 Asi
a
-P
acific. 201
4:
846-
848.
[28]
H Murata, N Kohmu, YN W
ija
ya
nto, Y Okamura. Integrati
o
n
of
Patch Antenna o
n
Optical
Modu
lators
.
IEEE Photonic
s
Society News
. 2014; 28(
2).
[29]
YN W
ija
yanto,
D Mahmudi
n, P Daud
. Prop
osal of F
i
ber-
R
e
m
ote
d
Rad
a
r Systems.
Procee
din
g
o
n
Internatio
na
l
Confer
ence
o
n
Ra
dar, Ant
enn
a,
Micro
w
ave, Electr
oni
cs and
T
e
lecommunic
a
tio
n
s
(ICRAMET
)
. Bali. 20
12: 73-
7
6
.
[30]
YN W
ija
ya
nto,
A Ka
nno,
A
A
F
a
thna
n, P
Dau
d
, T
Kaw
a
nis
h
i,
D M
ahmu
d
in,
N
Yamamoto.
Metamateri
al
Antenn
a Inte
gr
ated to
Li
NbO
3
Optica
l Mo
d
u
lator f
o
r Mil
l
i
m
eter-W
av
e-P
hoton
ic L
i
nks.
Internatio
na
l Sy
mp
osi
u
m Antenn
a an
d
Prop
agati
on (ISAP).
T
a
smania. 20
15: 3-7.
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