Indonesian Journal of
Electrical
Engineer
ing and
Computer Science
V
o
l. 10
, No
. 3, Jun
e
20
18
, pp
. 86
7
~
87
4
ISSN: 2502-4752,
DOI: 10.
11591/ij
eecs.v10
.i3.pp867-874
8
67
Jo
urn
a
l
h
o
me
pa
ge
: http://iaescore.c
om/jo
urnals/index.php/ijeecs
A Compact Bandpass Filter Usin
g a T-shaped
Loaded Open-
Ended Stub Resonator
Ali Ny
ang
w
a
r
ima
m
Obadiah,
Mohama
d
Ri
jal
H
a
mid, Mohamad
K
a
mal Abd Rahi
m,
No
or Asniz
a
Mur
a
d
Ad
va
nced
R
F
and
M
i
cro
w
a
v
e R
e
searc
h
Gr
ou
p
(AR
F
M
R
G),
C
o
m
m
uni
cat
i
on E
n
gi
nee
r
i
n
g
De
pa
rt
m
e
nt,
Facu
lty of Electrical En
g
i
n
eeering
,
Un
iv
ersiti Tekno
log
i
Malaysia (UTM),
Jo
hor
Bah
r
u
,
Jo
hor
, 81
310
M
a
laysia
Article Info
A
B
STRAC
T
Article histo
r
y:
Received Ja
n
9, 2018
R
e
vi
sed M
a
r
2,
2
0
1
8
Accepted
Mar 18, 2018
This paper
prop
oses a compact
bandpass
filter u
s
ing a lo
aded op
en-ended
T-
shaped stub. Th
e open-end
e
d
T-shaped stub
is lo
a
d
ed with
vert
ic
al
resonators
plac
ed acros
s
.
T
h
e ke
y advan
t
ag
e of us
i
ng vertical resonato
rs in the design is
the sim
p
lici
t
y
a
nd low insertio
n loss it provid
e
s. The stru
ctur
e used is an
open-ended stub
attached
on one end to th
e tr
ansmission line (
λ
/2
) to form
a
T-s
h
aped res
o
n
a
tor (
λ
/4) hav
i
ng vertical res
onators placed across. The
vertical resonato
r position
al
ters
the posit
ion
at
which th
e tr
ansm
ission zero
occurs
. A pair o
f
the T-s
h
aped r
e
s
ona
tor is placed on para
lle
l
side
s of the
feed line. Th
e proposed filter is
designed
with the
aid o
f
Computer
Simulation Tech
nolog
y
Microwave Studi
o Software.
The propos
ed concept
is verified b
y
d
e
signing filters wi
th f
our different
verti
cal resona
to
r positions.
The filter possesses a good rejection and low insertion loss of
< 2dB with
Cheb
y
s
hev r
e
sponse. This filter
is
suited for modern-day
co
mmunication
applications since it shows good
re
jection
of ou
t
of band sign
als.
K
eyw
ords
:
Band re
ject
Ban
d
p
a
ss filter
Ope
n
st
u
b
R
e
s
onat
o
r
Sk
irt selectiv
it
y
Transm
ission zero
Copyright ©
201
8 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
M
oham
a
d R
i
ja
l
Ham
i
d,
C
o
m
m
uni
cat
i
o
n E
n
gi
neeri
n
g
Depa
rt
m
e
nt
,
Facu
lty of Electri
cal Engineering,
Uni
v
ersi
t
y
o
f
Tech
nol
ogy
M
a
l
a
y
s
i
a
, 81
3
1
0
,
Jo
ho
r B
a
hr
u,
M
a
l
a
y
s
i
a
.
Em
a
il: rij
a
l@fk
e.u
t
m
.
my
1.
INTRODUCTION
The ra
pi
d a
d
v
a
ncem
ent
of m
odern com
m
uni
cat
i
o
n sy
st
em
s and t
h
e co
nge
st
i
on
of ra
di
o s
p
ect
rum
h
a
v
e
m
a
d
e
m
u
ltifu
n
c
tion
a
l and
m
u
lt
ib
an
d
d
e
v
i
ces a resear
ch
ho
tspo
t. Band
p
a
ss filters are p
r
im
e
co
m
p
on
en
ts
in
co
mm
u
n
i
catio
n
system
s as th
ey h
e
lp to
i
n
h
i
b
it in
terferen
ce an
d
prov
ide th
e n
e
ed
ed
selectio
n
of th
e
sig
n
a
l
b
a
nd
. Ban
d
p
a
ss filters th
at p
o
ssess h
i
gh
selectiv
ity in
th
e p
a
ssb
an
d
are n
e
ed
ed
t
o
su
it mo
d
e
rn
co
mm
u
n
i
catio
n
ap
p
lication
s
.
Co
n
t
ro
llin
g th
e tran
sm
issio
n
zero po
sitio
n is
v
e
ry im
p
o
r
tan
t
to
research
ers
in
prev
en
ting
i
n
terferen
c
e
with
ad
j
acen
t
freq
u
e
n
c
y
b
a
nd
s.Vari
o
u
s
tech
n
i
q
u
e
s h
a
v
e
b
een u
s
ed
t
o
mak
e
b
a
n
d
p
a
ss filter su
it mo
dern
com
m
uni
cat
i
on char
act
eri
s
t
i
c
s [1-
1
4]
. A fi
xed f
r
e
que
ncy
ope
n en
ded t
a
ppe
d st
u
b
wi
t
h
go
o
d
sel
ect
i
v
i
t
y
is
sh
own
in
[1
] an
d [2
].Band
pass filters
u
s
ing
a tun
e
d
tapp
ed stub
wit
h
a v
a
racto
r
to yield
recon
f
i
g
urab
le
t
r
ansm
i
ssi
on z
e
ros
an
d t
una
bl
e fre
q
u
ency
ra
nge
i
s
p
r
ese
n
t
e
d i
n
[
3
,
4]
. I
n
[
5
]
,
a st
e
ppe
d i
m
pedance res
o
nat
o
r i
s
u
s
ed
to co
n
t
ro
l
th
e t
r
an
sm
issi
o
n
zero and
pro
d
u
c
e a low in
sertio
n lo
ss
filter.
A
wide tun
i
n
g
rang
e is presen
ted
by
t
h
e use of
paral
l
e
l
cou
p
l
e
d l
i
n
es i
n
[6]
.
Thi
s
t
echni
q
u
e gi
ves a ve
r
y
goo
d ret
u
r
n
l
o
ss and re
je
ct
i
on;
ho
we
ver t
h
e i
n
sert
i
on l
o
ss pe
r
f
o
r
m
a
nce i
s
relat
i
v
el
y
hi
gh as
it is
clo
s
e to
3
d
B. Cen
t
rally lo
ad
ed
reson
a
tors are
use
d
t
o
pr
op
os
e t
una
bl
e pass
ban
d
s
[7]
f
o
r d
u
al
ba
nd
s. C
o
n
t
rol
l
a
bl
e pa
ssb
and
fre
q
u
enci
e
s
an
d ba
n
d
wi
d
t
hs b
y
u
s
ing
a m
u
lti-stu
b
load
ed
reso
n
a
t
o
r
with
com
p
act size is
d
e
m
o
n
s
trated
[8
] ho
wev
e
r th
i
s
d
e
sign
is com
p
lex
.
Mu
ltib
and
tunab
l
e filters
h
a
vin
g
go
od
ch
aracteristics
su
itab
l
e fo
r m
o
d
e
rn co
mm
u
n
i
catio
n
system
s are sh
own
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
502
-47
52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
86
7 – 87
4
86
8
in
[9
,
10
].
A
v
a
ract
o
r
t
u
n
e
d op
en
ring
reso
n
a
t
o
r is u
s
ed in
[15
]
to
d
e
sig
n
a t
u
n
a
b
l
e
b
a
ndp
ass
filter with
ab
so
lu
te b
a
ndwid
th.
In [
1
6]
, a T sh
aped
res
onat
o
r
i
s
al
so used
b
u
t
wi
t
h
out
ve
rt
i
cal
resonat
o
rs
.
In t
h
i
s
p
a
pe
r,
an i
m
prove
d
t
echni
q
u
e
f
o
r
desi
g
n
i
n
g t
h
e
ope
n
-
en
de
d t
a
ppe
d
st
u
b
(
T
-s
hape
d
res
onat
o
r)
ba
nd
pass
fi
l
t
er wi
t
h
com
p
act
si
ze
an
d sh
arp
selectiv
ity is p
r
esen
ted
.
As
co
m
p
ared
with o
t
h
e
r d
e
sign
s [2
, 3],
th
e p
o
sitio
n o
f
th
e
l
o
ad
ed v
e
rtical
reso
nat
o
r af
fec
t
s t
h
e t
r
ansm
i
s
si
on ze
ro f
r
e
q
uency
a
nd m
a
kes t
h
e si
ze m
o
re c
o
m
p
act
. In p
r
evi
ous
des
i
gns
usi
n
g t
h
e T
-
s
h
aped st
ub
, t
h
e
fre
que
ncy
i
s
chan
ge
d by
i
n
c
r
easi
ng t
h
e l
e
n
g
t
h
of t
h
e st
ub
fr
om
it
s end.
In t
h
i
s
design,
Ve
rtical resonators a
r
e placed
across
the
ope
n-e
n
de
d stub t
o
c
h
ange
the
transm
is
sion ze
ro fre
q
uency.
Th
e in
t
r
odu
ctio
n
of v
e
rtical reson
a
tors acro
ss th
e op
en
-en
d
e
d
st
u
b
results in
a ch
an
g
e
in
th
e ch
aract
eristics
im
pedance
o
f
t
h
e s
h
unt
st
u
b
whi
c
h t
h
ere
b
y
affect
s t
h
e
fre
quency
at which transm
ission zero occ
u
rs. One pai
r
o
f
T-sh
aped
reso
nato
r
of th
e
sam
e
e
l
ectrical
len
g
t
h
is coup
led
t
o
bo
th
sid
e
s
o
f
t
h
e transmissio
n
lin
e.
Two
pai
r
s o
f
ve
rt
i
cal
resonat
o
rs a
r
e used i
n
t
h
e
d
e
si
gn t
o
s
h
o
w
fo
ur
di
ffe
re
nt
freq
u
e
n
cy
st
at
es. Thi
s
desi
gn
has a
v
e
ry
g
ood
rej
e
ctio
n
an
d
l
o
w i
n
sertion
l
o
ss
of < 2d
B,
t
h
ereb
y m
a
k
i
n
g
it a g
ood
can
d
i
d
a
te for m
u
ltifu
n
c
tio
n
a
l
devi
ces
.
2.
PR
OPOSE
D
FILTER
D
E
SIGN
STRUCTU
R
E
The f
u
ndam
e
nt
al
st
ruct
ure
us
ed i
n
t
h
e
desi
gn i
s
s
h
o
w
n i
n
Fi
g
u
re
1. I
n
t
h
i
s
st
ruct
u
r
e
an i
n
di
rect
l
y
co
up
led
tran
smissio
n
lin
e reso
nato
r
(
λ
/
2
) i
s
t
a
ppe
d at
t
h
e cent
e
r by
an
o
p
en
-e
nde
d st
u
b
.
The o
p
e
n
-e
n
d
e
d st
u
b
co
m
b
in
es with th
e tran
sm
issi
o
n
lin
e
reson
a
to
r t
o
form
a T-sh
ap
ed
reson
a
tor (
λ
/
4
)
.
T
h
i
s
ope
n-e
n
de
d st
ub
fo
rm
s a shu
n
t
whi
c
h i
s
e
qui
v
a
l
e
nt
t
o
a LC
r
e
so
nat
o
r
i
n
se
r
i
es whi
c
h
pr
od
uces a t
r
a
n
sm
issi
on
zer
o. T
h
eref
ore
th
e tran
sm
issi
o
n
zero
larg
el
y d
e
p
e
nd
s
on
th
e sh
un
t st
u
b
ch
aracteristics. To
tun
e
th
e t
r
an
sm
issio
n
zero the
charact
e
r
i
s
t
i
c
s of
t
h
e s
h
unt
st
u
b
wo
ul
d
ha
ve t
o
be al
t
e
re
d.
Fig
u
re
1
.
T-sh
ap
ed b
a
nd
p
a
ss
filter
The
gene
ral
i
zed eq
uat
i
o
n
of
t
h
e desi
gn
(i
m
p
eda
n
ce t
r
a
n
s
f
orm
i
ng eq
uat
i
o
n
)
s
h
o
w
s t
h
e
rel
a
t
i
ons
hi
p
bet
w
ee
n t
h
e el
ect
ri
cal
l
e
ngt
h
of st
ub
, cha
r
ac
t
e
ri
st
i
c
s im
pedance an
d t
h
e
fr
eque
ncy
(
f) at
whi
c
h t
r
a
n
sm
issi
on
zero
occ
u
rs as
i
n
Eq
uat
i
o
n (
1
)
.
Z
0
re
prese
n
t
s
t
h
e chara
c
t
e
ri
st
i
c
im
pedan
ce of t
h
e st
u
b
s
on
b
o
t
h
si
des
of t
h
e
feedline
,
θ
0
represe
n
ts the electrical length of the stub
at the given transm
ission zero. The ge
ne
ralized
equat
i
o
n
use
d
i
n
t
h
e
desi
g
n
s
h
ows
t
h
at
a
c
h
a
nge i
n
the e
f
fe
ctive electrical lengt
h
Ɵ
0
of
the
stub would affect
the the
fre
que
n
cy
f
o
at
whi
c
h t
r
ansm
i
ssi
on ze
ro
occ
u
r
s
.
Ɵ
(
1
)
The sam
e
dim
e
nsi
o
ns
of T
-
s
h
ape
d
reso
nat
o
r are c
o
u
p
l
e
d t
o
b
o
t
h
si
des
of
t
h
e t
r
ansm
i
ssion l
i
n
e
.
T
h
i
s
has m
i
nim
a
l
ef
fect
o
n
t
h
e
ce
nt
er
fre
que
ncy
as can
be see
n
i
n
Fi
g
u
re
2.
Fi
gu
re
2
depi
c
t
s t
h
e com
p
ari
s
on
o
f
havi
ng
ei
t
h
er
one
o
r
t
w
o
T
-
sha
p
e
d
reso
n
a
t
o
rs
co
u
p
l
e
d
t
o
t
h
e
t
r
a
n
sm
issi
on
l
i
n
e.
T
h
i
s
desi
g
n
e
d
ca
n
be
com
p
ared t
o
[12].
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
A Compa
c
t Ban
dpa
ss Filter
Using
a
T-sh
ap
ed loa
d
e
d
…
(
A
l
i
N
y
an
gw
ari
m
a
m
O
b
a
d
i
a
h)
86
9
Fi
gu
re
2.
C
o
m
p
ari
s
on
o
f
o
n
e
and
t
w
o T
-
s
h
a
p
ed
res
o
nat
o
rs
B
y
pl
aci
ng
ve
r
t
i
cal
reso
nat
o
r
acr
oss t
h
e
o
p
e
n-e
n
ded
res
o
nat
o
r, t
h
e c
h
ar
act
eri
s
t
i
c
im
pedance
of t
h
e
shu
n
t
st
u
b
i
s
al
t
e
red t
h
ere
b
y
affect
i
n
g t
h
e f
r
e
que
ncy
at
wh
i
c
h t
r
ansm
i
ssi
on zer
o occ
u
rs
. C
onse
q
uent
l
y
whe
n
t
h
e ve
rt
i
cal
res
onat
o
r i
s
pl
ace
d at
di
ffe
rent
distance from
the transm
ission
lin
e res
onat
o
r t
h
ere is a
shift i
n
the
fre
que
ncy
at
whi
c
h t
r
a
n
sm
issi
on
zer
o
occ
u
rs
. T
h
e
shi
f
t
i
n
f
r
e
que
ncy
o
f
t
r
a
n
sm
i
ssi
on
zero
i
s
ca
use
d
by
t
h
e
v
e
rtical reson
a
to
r in
tro
d
u
c
ing a n
e
w effective reson
a
n
t
leng
th
wh
ich
st
o
p
s at th
e v
e
rtical reso
n
a
t
o
r
p
o
s
itio
n.
Thi
s
i
s
sh
ow
n i
n
Fi
g
u
re
3.
In
Fi
gu
re 3
,
t
h
e
v
e
rt
i
cal
reso
nat
o
r i
s
pl
ace
d b
e
t
w
een
3m
m
and 7m
m
away
fro
m
t
h
e
transm
ission line. As the St
ub is placed further a
w
ay
from the trans
m
ission lin
e the transm
ission zero is
m
oved t
o
war
d
s
t
h
e l
o
we
r f
r
e
q
uency
.
The ve
rtical resonator
produces
an effect on the c
h
aract
eristics im
pedance which ac
ts as a band
reject
/
s
t
o
p, t
h
e
r
eby
pr
o
duci
n
g a t
r
a
n
sm
i
ssion
zer
o at
s
u
c
h
f
r
e
que
ncy
o
f
re
ject
i
o
n. T
h
i
s
beha
vi
o
r
gi
ves a
b
a
ndp
ass filter effect p
r
od
u
c
in
g
a sh
arp
selectiv
ity
a
t
b
o
t
h
th
e lo
wer an
d
u
p
p
e
r frequ
en
cy b
a
nd
.
As the
fre
que
ncy
of t
r
ansm
i
ssi
on zer
o i
s
m
oved
,
t
h
e
pass
ba
nd
f
r
eq
uency
i
s
al
s
o
c
h
an
ge
d ei
t
h
e
r
t
o
t
h
e
hi
ghe
r
or
l
o
we
r
fre
que
ncy
.
(a)
(b)
(c)
Figu
re
3.
Para
m
e
ter sweep
s
h
o
w
in
g t
h
e
e
f
fect of Ve
rtical resona
tor
on the open ende
d s
t
ub
(a) Structure
(b
) S
1
1 (
c
)
S2
1
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I
S
SN
:
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52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
86
7 – 87
4
87
0
3.
THEORETICAL AND E
X
PERIME
NTAL RESULTS
Fi
gu
re
4 sh
o
w
s t
h
e fi
nal
des
i
gn st
r
u
ct
u
r
e a
f
t
e
r va
ri
o
u
s
pa
ram
e
t
r
i
c
st
udi
es were ca
rri
e
d
o
u
t
wi
t
h
vertical res
ona
tors
placed
on
bot
h sides
of t
h
e T-s
h
a
p
e
d
re
so
nator. A
pair of the
ve
rtical resonator is pla
ced at
d
i
fferen
t
leng
th
s
o
n
bo
th sides of th
e ind
i
rectly fed
lin
e. Each Vertical resonator
pai
r
pr
o
duces
a di
f
f
ere
n
t
cen
ter
frequ
ency wh
ile m
a
in
tain
in
g a sh
arp
rej
ection
wh
ic
h
is an
im
p
o
r
tan
t
ch
aracteristic fo
r
filters.
Sin
ce t
h
e
vertical res
ona
tors a
ffects t
h
e fre
quency at
whic
h tr
a
n
smission ze
ro
oc
curs
, the
ce
nt
e
r
f
r
eq
ue
ncy
i
s
al
so
affected whe
n
e
v
er the tra
n
sm
ission zer
o
p
o
si
t
i
on c
h
an
ges
as
i
n
t
h
e
de
si
g
n
.
Th
e
b
a
ndp
ass
filter is d
e
signed
u
s
i
n
g
a l
o
w co
st FR
4
bo
ard
wit
h
a d
i
electric co
n
s
tan
t
o
f
4
.
3
an
d
th
ick
n
e
ss
o
f
1.6
m
m
.
Th
e
v
a
lu
es
o
f
th
e filter
d
i
m
e
n
s
io
n
s
are as fo
llo
ws
:
L = 38 mm
, W
=
3
4
mm
, G =
5
m
m
,
f
= 3 mm
, dg
= 0.
2 mm
, d1
= 4.
8 mm
, d2
= 7 mm
, u = 22
.5
m
m
,
v = 14
m
m
,
s = 4 mm
, ds = 10
mm
and
dw
= 1.
5 m
m
.
The cent
e
r f
r
e
que
ncy
o
f
t
h
e T-sha
p
e
d
re
son
a
t
o
r
desi
g
n
e
d i
s
3.5
GHz
wi
t
h
o
u
t
pl
aci
ng t
h
e
vert
i
cal
res
ona
t
o
rs. B
y
pl
aci
ng
o
n
e pai
r
of
vert
i
cal
reso
n
a
t
o
rs
on
bot
h
si
des o
f
t
h
e t
r
ansm
i
ssi
on l
i
n
e t
h
e
effective
res
onance le
ngt
h
of
the stub is c
h
a
nge
d. T
h
e
vert
i
cal
res
onat
o
rs
are placed
in four differe
n
t
st
ates
as
sho
w
n i
n
fi
g
u
r
e
5 t
o
8. F
r
om
t
h
e res
u
l
t
s
fo
u
r
(4
) st
at
es o
f
f
r
e
que
ncy
are
o
b
t
ai
ned. T
h
e
r
ef
o
r
e t
h
e f
r
e
que
nc
y
can
b
e
ch
ang
e
d
while also
altering
th
e tran
sm
iss
i
o
n
zero
s.
Th
e
v
e
rtical stu
b
on th
e left is lab
e
led L
while th
at
on
th
e
righ
t is lab
e
led R. By
p
l
acin
g
a
p
a
ir
o
f
L
and
R
at
di
ffe
r
e
nt
l
e
n
g
t
h
al
o
n
g
t
h
e
st
u
b
a
sp
eci
fi
c ba
nd
pas
s
fr
eq
ue
ncy
i
s
pr
o
duce
d
.
The
effect
i
v
e re
so
nanc
e
l
e
ngt
h i
s
al
t
e
re
d o
n
bot
h t
h
e
Left
an
d R
i
g
h
t
si
de T-s
h
a
p
ed
st
ubs t
o
p
r
o
d
u
c
e
di
ffe
re
nt
p
o
si
t
i
ons o
f
t
r
a
n
sm
i
ssi
o
n
zero
s
. Th
e
v
e
rtical reson
a
to
rs po
sitio
ns are p
l
aced
in th
e
fo
llowing
d
i
men
s
ion
s
,
St
at
e 1;
d
1
= 3.
3 m
m
an
d
d2 =
5 m
m
, S
t
at
e 2; d
1
= 3
.
3 m
m
a
nd
d2
= 7 mm
, St
at
e 3; d
1
= 1.
3
mm
an
d d
2
=
5 mm,
an
d St
at
e 4
;
d1
= 1.
3 m
m
an
d d
2
=
7
m
m
. Th
erefo
r
e fro
m
Fig
u
re
5
t
o
8
,
it is
o
b
serv
ed th
at th
e Vertical stu
b
positio
n
affects t
h
e
b
a
nd
p
a
ss freq
u
e
n
c
y b
e
h
a
v
i
or
o
f
th
e
filter.
Fig
u
re
4
.
Filter stru
ct
u
r
e
Fi
gu
re
5.
Si
m
u
l
a
t
e
d an
d M
eas
ure
d
st
at
e
1
res
u
l
t
Fi
gu
re
6.
Si
m
u
l
a
t
e
d an
d M
eas
ure
d
st
at
e
2
res
u
l
t
s
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
A Compa
c
t Ban
dpa
ss Filter
Using
a
T-sh
ap
ed loa
d
e
d
…
(
A
l
i
N
y
an
gw
ari
m
a
m
O
b
a
d
i
a
h)
87
1
Fi
gu
re
7.
Si
m
u
l
a
t
e
d an
d M
eas
ure
d
st
at
e
3
res
u
l
t
s
Fi
gu
re
8.
Si
m
u
l
a
t
e
d an
d M
eas
ure
d
st
at
e
4
res
u
l
t
s
(a)
(b
)
Fi
gu
re
9.
Si
m
u
l
a
t
i
on R
e
sul
t
s
of
al
l
st
at
es (a)
S1
1
(b
)
S2
1
(a)
(b
)
Figu
re
1
0
. M
e
a
s
ure
d
Res
u
lts
o
f
all states (a
)
S1
1 (
b
) S
2
1
Table 1. Operating Frequen
c
y
and
Band
width at different states
STAT
E 1
STAT
E 2
STAT
E 3
STAT
E 4
Center
fr
equency
Bandwidth
Center
fr
equency
Bandwidth
Center
fr
equency
Bandwidth
Center
fr
equency
Bandwidth
Sim
u
lated
3.
52
100.
1
3.
41
288.
9
3.
67
286.
4
3.
57
597
M
easur
ed
3.
47
126.
8
3.
38
279.
2
3.
62
393.
6
3.
52
598
The
resul
t
s
w
e
re si
m
u
l
a
t
e
d usi
n
g C
S
T
m
i
cro
w
a
v
e st
u
d
i
o
a
nd
val
i
d
at
e
d
t
h
ro
u
g
h
fa
br
i
cat
i
on an
d
measu
r
em
en
t in
th
e labo
rato
ry. Th
e co
m
p
arison bet
w
een the sim
u
lated a
n
d m
easured results of eac
h
state of
th
e tu
n
a
b
l
e
b
a
n
d
p
a
ss
filter is sho
w
n
in
figure 5
t
o
8. A
p
l
o
t
of bo
th
t
h
e frequ
e
n
c
y and
tran
sm
issio
n
zero
s are
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
502
-47
52
I
ndo
n
e
sian
J Elec Eng
& Com
p
Sci, V
o
l. 10
,
No
.
3
,
Jun
e
2
018
:
86
7 – 87
4
87
2
sh
own
.
A sligh
t
d
i
sp
arity b
e
tween
t
h
e simu
lated
an
d m
e
asu
r
ed
resu
lts ex
ists as a
resu
lt o
f
th
e
no
n-id
eal
fabricatio
n and m
easu
r
em
en
t
p
r
o
cess as com
p
ared
with
t
h
e sim
u
latio
n
s
. Each filter state is seen to possess a
Sh
ar
p r
e
j
ection and
low
i
n
sterio
n
l
o
ss. Th
e f
i
lter
is seen to
hav
e
a C
h
eb
yshev
r
e
spon
se.
Fi
gu
re 9 a
n
d
10 s
h
ows t
h
e
com
b
i
n
ed pl
ot
i
n
t
uni
ng t
h
e
fre
que
ncy
an
d t
r
an
sm
i
ssi
on zeros
of t
h
e
si
m
u
lated
an
d
measu
r
ed
resu
l
t
s resp
ectiv
ely. Th
e resu
lts are d
e
p
i
cted
in
Tab
l
e 1
.
Th
e filter si
m
u
latio
n
resu
lts
sh
own
in
f
i
gu
re 9
can
b
e
tuned
to
op
er
ate at 3
.
52
, 3.41
,
3
.
6
7
or
3.57
G
H
z. Th
e m
easu
r
ed
r
e
su
lts in
f
i
g
u
r
e
10
can
op
erate at 3
.
4
7
, 3.38
, 3.62
or
3
.
5
2
GHz
resp
ectiv
el
y. Th
e flex
ib
ility o
f
th
e
p
r
op
o
s
ed filter sho
w
s it is a
g
ood
can
d
i
d
a
te for m
u
ltifu
n
c
t
i
o
n
a
l
d
e
v
i
ces
wh
ere in
terferen
ce
with
ad
j
a
cen
t
b
a
nd
is an
issu
e. Th
e
fab
r
icated
Pro
t
o
t
yp
e
o
f
the filter is sh
own
in Figure
1
1
.
(a)
(b
)
(c)
(d
)
Fi
gu
re 1
1
. Fab
r
i
cat
ed pr
ot
ot
y
p
e (a
)
State 1
(b) State 2 (c
) State 3
(d
) State
4
4.
CO
NCL
USI
O
N
Thi
s
pa
per
pr
esent
s
a n
ove
l
way
creat
i
ng t
h
e t
r
an
sm
issi
on ze
ro
of
an T-s
h
ape
d
ope
n-e
n
de
d
reson
a
tor. Th
e filter co
nsists o
f
a T
sh
ap
ed
reson
a
tor
o
n
parallel sid
e
s of th
e tran
sm
issi
o
n
lin
e. Th
e vertical
reso
nat
o
rs
p
o
si
t
i
oned
acr
oss
t
h
e
ope
n
-
en
d a
f
fect
s t
h
e
fre
quency at which
the tra
n
simmion ze
ro occ
u
rs.
The
p
r
op
o
s
ed
b
a
n
d
p
a
ss filter
is d
e
sig
n
e
d
at
fou
r
d
i
fferen
t
states
to
p
r
ov
e
t
h
e
co
n
c
ep
t . Dep
e
nd
ing
o
n
th
e
positio
n
o
f
th
e
v
e
rtical reson
a
tor, th
e
filter can
op
erate at 3
.
4
7
, 3.38
,
3
.
6
2
o
r
3
.
5
2
GHz cen
t
er freq
u
e
n
c
y. Each state
h
a
s
v
a
ryin
g ban
d
wid
t
h
s
wh
ile m
a
in
tain
in
g go
od filter
re
j
ectio
n ch
aract
eristics. Th
e
desig
n
is su
itable for
m
u
lt
i
f
unct
i
o
na
l
devi
ces
w
h
i
c
h a
r
e
pre
dom
i
n
ant
l
y
avai
l
a
bl
e
fo
r
prese
n
t
day
m
odern
com
m
uni
cat
i
o
n sy
st
e
m
s.
ACKNOWLE
DGE
M
ENTS
Th
is
work is supp
orted b
y
Un
i
v
ersiti Te
k
n
o
l
og
i Malaysia, g
r
an
t reference nu
m
b
er:
Q
.
J1
300
00
.26
2
3
.
1
4
J
18
Evaluation Warning : The document was created with Spire.PDF for Python.
In
d
onesi
a
n
J
E
l
ec En
g &
C
o
m
p
Sci
ISS
N
:
2
5
0
2
-
47
52
A Compa
c
t Ban
dpa
ss Filter
Using
a
T-sh
ap
ed loa
d
e
d
…
(
A
l
i
N
y
an
gw
ari
m
a
m
O
b
a
d
i
a
h)
87
3
REFERE
NC
ES
[1]
J.-R. Lee, J.-H
.
Cho, and S.-W.
Yun,
"New compact b
a
ndpass filter using micr
ostrip/spl lambda//4 resonators with
open stub
inver
t
er,"
I
EEE
Mi
cr
owave and
Guide
d
Wave
L
e
t
t
er
s
,
vol. 10
, no
. 12
, p
p
. 526-527
, 200
0.
[2]
L. Zhu and
W. Menzel,
"Compact
mi
crostrip
bandpass filter with two tr
ansm
ission zeros using
a stub-tapp
ed h
a
lf
-
waveleng
th line
resonator,"
IEEE Mic
r
owave
and
Wire
le
ss Compone
n
ts Le
tte
rs,
vo
l. 13
, no
. 1
,
pp
. 1
6
-18, 2003
.
[3]
H. Zhang
and
K. J. Chen, "Bandpass
filters w
ith reconfigurab
le tr
ansm
issi
on zeros using varactor-tun
ed tapp
ed
stubs,"
IEEE Microwave and
wir
e
less componen
t
s letters,
vo
l. 16, no. 5, pp. 249-2
51, 2006
.
[4]
R. Zhou
, I
.
Man
d
al, and H
.
Zh
an
g, "Microwav
e
b
a
ndpass
filters w
ith tun
a
ble center
frequen
c
ies an
d reconf
igurable
transmission zer
os,"
Microwave and
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4
BIOGRAP
HI
ES OF
AUTH
ORS
ALI N
YANG
WARIM
A
M
OBADIAH
received his
Bache
l
or of Engineer
i
ng (B.Eng.) in
Electrical and C
o
mputer Engineering from the
Fe
deral un
iversity
of Technolog
y
Minn
a, Nig
e
r
state, Niger
i
a in 2010 and a
Master of Engineer
ing (M
.Eng
.) in Electrical-
E
lectronics and
Telecommunication Engineering from the University
of Technolo
g
y
Malay
s
ia in 2014. He has
been purs
u
ing
hi
s
P
h
D degree
in
ele
c
tri
cal
eng
i
ne
ering
at
the
Univ
ers
i
t
y
of
Te
chno
log
y
M
a
l
a
y
s
ia
since 2014. His research interest includes Radi
o frequency
d
e
vices, reconfigu
r
able an
tennas
,
filte
rs and
fil
t
er-
a
ntenn
a
s.
M
OHAM
AD R IJAL HAM
I
D
rece
ived
the M
.
S
c
. degr
ees
in
communication engineer
ing from
the Universiti Teknologi Malay
s
ia,
Johor B
a
hru, Malay
s
ia, in 20
01 and the Ph
.D Degree
at th
e
Universit
y
of Bi
rm
ingham
,
Birmingham
,
U.K.
in 2011. He has b
een with Univer
siti Teknolog
i
Malay
s
ia (UTM)
at the F
acu
lty
of
Electrical Eng
i
n
eering (F
KE), U
T
M, since 1999.
Currently
his
position is
a Senior Lectur
er. H
i
s major r
e
search
interest is
reconfigurab
le
antenna design
for
m
u
ltim
ode wirel
e
ss applications
. He was award
e
d a schol
arship
from
the Univer
siti T
e
knologi
Mala
y
s
ia
to
furt
her stud
y
in
the
U.K.
M
OHAM
AD K AM
AL A.
RAHIM
was born
in Alor Setar,
Ke
dah, Malay
s
ia in 1964
. He
obtain
e
d his B.Eng. in Electric
al and Electronic from University
of Strathcly
d
e, U.K. in 1987
and M.Eng
.
fro
m University
of
New South Wales, Australia in
1992. He r
e
ceiv
ed his Ph.D. in
the field of Wideband Active
Antenna. He is
a Professor at Communicatio
ns Engineer
ing
Department, Faculty
of
Electri
cal
Enginn
ering
at Univ
ersiti
Teknologi Malay
s
ia. Professor
Mohamad Kamal is a senior
me
mber of IEEE since 2007
.
His research
in
terest
includ
es
antenn
as
, m
e
t
a
m
a
ter
i
als
,
bod
y-ar
ea
com
m
unicati
ons
, and
recon
f
i
gurable
ant
e
nnas
.
NOOR ASNI
ZA M
URAD
ob
tain
ed her
first
degree in
200
1 from
Universiti
Teknolog
i
Malay
s
ia (U
TM), Malay
s
ia, with
Honors, majoring in telecomm
unication engineering.
Shortly
after
gradu
a
ted
,
s
h
e joined
UTM
as
a
tutor
at
tach
ed to
the D
e
part
m
e
nt of Radio
C
o
m
m
unication
Engineering (R
aCED), Faculty
o
f
Electrical Engineering (FKE)
,
UTM
.
S
h
e rec
e
i
v
ed her M
E
ng
.
in 2003 from th
e same university
and later has
been
appoin
t
ed
as a lectur
er in April 2003. She
joined Emerging
Device Techno
log
y
Group, Un
iversity
of Birmingha
m, UK and obtained h
e
r
Ph.D in 2011 f
o
r research on
m
i
crom
achined
m
illim
eterwav
e
circu
its. Her res
earch in
ter
e
sts
includ
e antenn
a
design for RF and m
i
crowave c
o
m
m
unication system
s, m
illim
et
erwave c
i
rcui
ts
design, and antenna
b
eamforming.
Curr
ently
,
Noor Asniza
Murad is a member of IEEE
(MIEEE), Mem
b
er of Antenna
and P
r
opagati
on (AP
/
MTT/E
M
C) Mala
y
s
i
a
Chapter
,
and a
Senior Lectur
er
at Faculty
of
Electrical Eng
i
neer
i
ng, Universiti Teknologi
Malay
s
ia (UTM).
Evaluation Warning : The document was created with Spire.PDF for Python.