Abstract— In this paper a planar elliptical CPW fed

monopole antenna with five band notched performance is

designed using multiple fractal slots. The proposed antenna is

etched on a TLY-5 (Taconic) PCB with an overall size of

41x45x0.782 mm3. Five band notches with sharp rejection can

be accomplished at Wimax band (3.3-3.7 GHz), WLAN (5.15-

5.825 GHz), RFID (6.8 GHZ), downlink of X-band satellite

communication system band (7.25-7.75 GHz), ITU uplink

satellite communication band (8.1 GHz). The antenna exhibits

an impedance bandwidth from 2.9 GHz to 12 GHz. The

simulation result of the above antenna has good impedance

matching, approximately omni-directional radiation pattern and

peak gain of 6.0 dBi.

Index Terms— Printed monopole antenna, ultra wideband

antenna, band-notched, half-wavelength slot

I. INTRODUCTION

In 2002 federal communications commission (FCC) has

permitted the utilization of 3.1 to 10.6 GHz band for

unlicensed use. Now a days due to wide application of ultra-

wide band (UWB) the radio system is being popular in the

field of academic and industries. UWB wireless

communication systems are dominant in today’s

communication world (1-4). While designing UWB antenna

the main emphasis is given to its compact size, gain,

omnidirectional radiation patterns [5-6], flat group delay [7-

9] response etc. Due to the interference between some

existing narrow bands such as WiMAX (3.3-3,7 GHz),

WLAN (5.15-5.825 GHz), RFID (centered at 6.8 GHz),

Downlink of X-band satellite communication system (7.25-

7.75 GHz) & ITU uplink satellite communication centered at

8.1 GHz and the UWB system, the design of such antennas

remains a permanent challenge to the antenna designers. So it

is mandatory to filter the overlapping frequency band for

Satyabrata Maiti is with the Kalinga Institute of Industrial Technology,

Bhubaneswar, Odisha, India currently pursuing his degree in M.tech (Phone:

+91 9434142788; E.mail: satyabratamaiti12@gmail.com

Sangita Das is with the Kalinga Institute of Industrial Technology,

Bhubaneswar, Odisha, India currently pursuing her degree in M.tech ( Email:

sangitadas716@gmail.com )

Dr. Amlan Datta holds a Associate Dean Position with the department of

Electronics Engineering at KIIT University, Bhubaneswar, Odisha, India

preventing the interferences. The printed monopole antenna

is very dominant among the proposed UWB antenna due to

ease of integration, small size, and simple fabrication with

compact front end. The coplanar waveguide (CPW) has

favourable advantages compared to micro strip feed line such

as unipolar configuration, easy integration, lower dispersion

in high frequency and it has minimal dependence on substrate

thickness. Five band-stop filters connected to the ultra wide

band antenna can be used to discard these bands. The basic

way to solve this problem is to design the UWB antenna with

notch band characteristics. Various UWB printed monopole

band notched characteristics have been presented. Various

type of slots namely rectangular slot [10], Hair pin slot [12],

using various fractal shape slot [14], L-shape slot [15], U-

shaped slot [16] etc have been reported to achieve notch

bands so far.

The paper is arranged such that section II describes the

antenna design and parametric study followed by results and

discussion in section III and conclusion in section IV.

II. ANTENNA DESIGN AND PARAMETRIC STUDY

The design of the proposed UWB antenna is shown in Fig.1.

The antenna is simulated by the Finite Integration method

using Time domain solver of CST microwave studio. The

substrate used is Taconic TLY-5 with thickness of 0.762mm,

relative dielectric constant €r of 2.2, and loss tangent of 0.02.

The proposed antenna has a size of 41x45x0.782 mm3. Five

band notches with sharp rejection can be accomplished for

Design and Analysis of Band-Notched UWB

Printed Monopole Antenna using Multiple Slots

Satyabrata Maiti, Sangita Das, Amlan Datta

(a)

International Conference on Communication and Signal Processing, April 3-5, 2014, India

978-1-4799-3357-0

Adhiparasakthi Engineering College, Melmaruvathur

257

Wimax (3.3-3.7 GHz), WLAN (5.15-5.825 GHz), RFID (6.8

GHZ), downlink of X-band satellite communication system

band (7.25-7.75 GHz), and ITU uplink satellite

communication band (8.1 GHz).The Printed UWB antenna

consists of a 50-Ω CPW feed line and a planar elliptical patch

with five slots of U shape, L-Shape, Levy fractal, Hair pin &

minkowski fractal slot. In this paper an elliptical shaped

monopole UWB antenna with five band notch characteristics

is proposed. A U Shape slot is etched from the feed line to

obtain notched band from 3.3GHz-3.7GHz. Two symmetrical

inverted L shaped slots are etched from the ground plane to

obtain notched band from 5.15 GHz to 5.85 GHz. A levy

fractal slot of the first iteration is etched out from the radiator

to create an RFID rejection band centered at 6.8 GHz. A

hairpin slot is etched out from the feed line to create a

Satellite rejection band centered at 7.4 GHz. Minkowski

fractal slot of second order iteration in the radiator results in

rejection band for X-band uplink satellite communication

centered at 8.1GHz.

Fig 2 Slot Configuration

The antenna was designed with the aid of CST microwave

studio, the dimensions of the optimized antenna prototype

are: Lsub=41, Wsub= 45, Lg=21.75, Wg=20.3, Wo=1.3,

Gp=0.55,Lp=0.75, L1=13.7, L2=8.2, Ts2=0.45, Z=2.0, Z1=3.0,

Ts1=0.55, s=0.67, Ts3=0, S1=0.5, D3=0.7, D1=3.8, Th1=3.5, S2=

17.4, TS3=1.

The antenna has compact size of 41x 45x0.762 mm3 on

Taconic substrate with €r=2.2.The location and shapes of the

slots were determined as shown in Fig 2.

For calculating, wavelength

eff

og

(1) ,

where o = is the free space wave length and

2

1

1212

1

2

1

W

hrrreff

(2)

A straight slot S2 was cut from the feed line with S1=0.5mm,

and length S2=17.4 mm, which is half wave length calculated

3.4 GHz in the Wimax band. The parametric studies are

carried out to investigate the effect of the slot on the band-

notched characteristics, as well as the impedance matching of

the antenna with different length. Two symmetrical L shape

slots in the ground plane results in band notch at 5.5 GHz.

The effective lengths of the L-shaped slots are initially

decided using formula (3), (4) and then optimized using CST

microwave studio.

L_S=L1+L2-Ts2 (3)

efff

cSL

2_ (4)

Here, c is the speed of the light.

Fig 5: Simulated VSWR for varying TS1

Fig 1: (a) Geometry of the proposed antenna. (b) U shape slot (c) L shape slot

(d) Levy fractal slot (e) Hair pin slot (f) Minkowski fractal slot

(b) (c) (d)

(e) (f)

Fig: 3 Fig: 4

Fig.3 & 4: Simulated VSWR for varying L1 & L2

258

Parametric study involving l1, l2, and ts2are depicted in fig 3,

4 & 5 respectively. It is observed that as l1inceases the notch

is shifted towards lower frequencies similar is observed by

varying l1, l2 & ts2.

The effective length of the U shape slot is initially calculated

Using (5) & (6) and then optimized using CST microwave

studio. The width and location of the slot are then adjusted to

exactly reject the centre frequency f2= 3.5 GHz for Wimax

system.

L_U=2S2+2S1 (5)

efff

cUL

22 (6)

Parametric studies involving length S2 and thickness S1 are

outlined in fig 6 and fig 7.The parametric study shows that as

the length and thickness S1 & S2 respectively decreases, the

notch band is shifted towards higher frequency without

affecting the other band notches.

The effective length of two Minkowski fractal slots in a patch

near the feed is chosen using (7) & (8) then optimized using

CST microwave studio. In equation 8, f3 represents the uplink

X-band satellite communication rejection band centre at 8.1

GHz.

SMINKOWSKIL 29_ (7)

efff

cMINKOWSKIL

32_ (8)

The parametric studies with variations in length S and

thickness TS3 respectively are shown in Fig 8 & 9. The

parametric studies show that as the length of the segment S

increases, the notched band shifts towards lower frequencies,

keeping the other notched bands intact, whereas the notched

band is shifted towards higher frequencies as slot width TS3

increases without disturbing other notched bands. The

parametric study shows that the optimum segment length S

and width t for notch frequency of 8.1GHz is 0.66mm and

0.25mm respectively.

L_L=6Z1+3Z (9)

efff

cLL

42 (10)

The effective length of the levy fractal slot is calculated using

(9) & (10) and then optimized using a CST microwave studio.

The Levy fractal slot in the radiator of the antenna consists

each of length Z1 and three identical segments each of the

length Z and whole slot is having thickness Ts1 in fig 10 &

fig 11.

The gap between the radiator patch and the ground plane is

given by Lp. An optimized value of Lp is obtained as 0.75mm.

The optimized width of CPW feed is 1.53mm.

III. RESULTS AND DISCUSSIONS

The antenna is simulated by CST microwave studio. The

dimension of the antenna is 41mmx 45 mm.

Fig: 6 Fig: 7

Fig: 8 Fig: 9

Fig.8 & 9: Simulated VSWR for varying S & TS3

Fig: 10 Fig: 11

Fig 10 & 11: Simulated VSWR for varying Z&TS1

Fig 12. Simulated VSWR of the antenna

(Except band notch)

Fig.6 & 7: Simulated VSWR for varying S1 & S2

259

The VSWR of the antenna is plotted in fig 12 and is found

that VSWR<2 except at the band notches.

The antenna exhibits an impedance bandwidth from 2.9 GHz

to 12 GHz with five notches at 3.3-3.7GHz(Wimax), 5.15-

5.825GHz(WLan),6.8GHz(RFID),7.25-7.825GHz

(Downlink of X-band satellite communication system), and

8.1GHz (uplink satellite communication).

Fig.13 shows the simulated VSWR of the designed antenna.

The current distributions at five notch frequencies are

depicted in fig14. It is seen that at lower frequencies the

current is mostly distributed along the sides of the slot. This

results in high attenuation at the notch frequency due to the

impedance mismatch at those frequencies. The notch centred

at 3.5 GHz is due to the U shaped slot and Hair pin slot in the

CPW feed line. Moreover the Levy fractal and Minkowski

fractal slot in the radiator result in notch band centred at

6.8GHz and 8.1 GHz.

The simulated peak gain is shown in fig15. The gain varies

from 2.5 dBi to 6.0dBi. The distortion less transmission of the

proposed antenna is confirmed by studying the group delay as

shown in fig16.

The simulated radiation patterns in the H plane (xz) and E

plane (yz) at 4.0, 7.0, and 10.0 are shown in fig17. The

antenna displays Omni directional pattern in the H plane and

bi directional pattern in the E plane.

Fig 13. Simulated VSWR of the proposed antenna

(a) (b)

(c) (d)

(e)

Fig14: Current distribution at (a) 3.4 GHz, (b) 5.5 GHz,

(c) 6.8 GHz, (d) 7.4GHz, (e) 8.1 GHz

260

IV. CONCLUSION

The paper presents a compact printed elliptical shaped UWB

antenna with five band notches using different fractal slots.

To obtain five notched bands, U shaped slot and a hair pin

slot were etched from the CPW feed line, Levy fractal and

Minkowski fractal were etched from the radiating patch and

L shape slots are etched from the ground plane. The antenna

has a peak gain of 6.0 dBi and good omnidirectional radiation

Patterns. Five notched bands are generated, at selected

frequencies, in an extremely wideband base antenna to

support multiple communication systems while avoiding

inference from other existing narrowband systems.

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