�ݺ�ߣ

JAWAHARLALNEHRU TECHNOLOGICALUNIVERSITY- GURAJADA-VIZIANAGARAM
VIZIANAGARAM – 535 003Andhra Pradesh (India)
DESIGN AND VALIDATION OF MULTI-BAND
RECONFIGURABLE ANTENNA FOR WIRELESS APPLICATIONS
UNDER THE ESTEEMED
GUIDANCE OF :
Prof. K.Chandra Bhushana Rao
Professor of ECE
JNTU-GV
BATCH 5:
19VV1A0401 - A.J.Sridhar
19VV1A0424 - J.Sai Sri
19VV1A0427 - K.Hema Malini
19VV1A0452 - Shaik Mohammeed Abbas
19VV1A0455 – S.Lochani Vilehya

CONTENTS:
 OBJECTIVE
 DESIGN PARAMETERS
 DESIGN EQUATIONS
 DESIGN AND VALIDATION PROCEDURE
 SIMULATION STEPS IN HFSS
 IMPLEMENTATION : 1. ANTENNA DESIGN STEPS
2. ANTENNA DESIGN
3. DESIGN PARAMETERS OF THE PATCH AND GROUND
4. PIN DIODE (BAR50-02V)
 PIN DIODE SWITCHING RESULTS
 CONCLUSION
STATUS REPORT

OBJECTIVE:
To design a Multi-band frequency reconfigurable antenna.
 Obtain results in terms of S parameter, E and H field patterns , 3-D gain plot , and
magnitude current distributions.
 To validate frequency reconfigurability of antenna with the help of switching of two
pin diodes.

DESIGN PARAMETERS:
1.S parameter : It describes how much the waves are reflected or transmitted from/ through a antenna.
The first parameter S11 is known as a reflection coefficient.
2. Resonant frequency : the frequency where maximum power is delivered to the patch of the antenna.
3.Gain : It is the ability of the antenna to radiate power more or less in any direction.
4.Directivity: the ratio of the radiation intensity in a given direction from the antenna to the radiation
intensity averaged over all directions.
5.Efficiency : It is the ratio of power radiated by the antenna to the power supplied to the antenna.
6.Front to back ratio: the ratio of power radiated in the front/main radiation lobe and the power radiated
in the opposite direction .
7.Impedance bandwidth: the range of frequencies where the antenna has good impedance matching and
can be heard by standing wave ratio (VSWR < 2) or module of the reflection coefficient (S11 <= -10 dB).

DESIGN EQUATIONS:
Empirical mathematical equations to
design square patch antenna are:
W =
Co
2𝑓𝑟
2
∈𝑟+1
, co is speed of light
∆𝐿
ℎ
= 0.412
∈𝑟𝑒𝑓𝑓+03
𝑊
ℎ
+0.264
∈𝑟𝑒𝑓𝑓−0.258
𝑊
ℎ
+0.8
L =
Co
2fr ∈𝑟𝑒𝑓𝑓
-2∆𝐿
 In the typical design procedure of antenna,
three essential parameters are:
1. Resonance frequency fr
2. Dielectric constant of the substrate, εr
3. Thickness of substrate, h
 By increase in the substrate's dielectric constant
(εr) and thickness (h) ,decreases the patch
dimensions and small changes in return loss,
bandwidth.

DESIGN AND VALIDATION PROCEDURE:
 Step-1: Synthesize the antenna dimensions based on the frequency of resonance, depending on the application.
 Step-2: Implement antenna design using simulation tool (HFSS).
 Step-3: Make the required changes to the antenna structure to get a multi-band operating response.
 Step-4: Include 2-pindiodes at appropriate places in the antenna structure.
 Step-5: Obtain the antenna design with 4 switching cases (ON-ON,ON-OFF,OFF-OFF,OFF-ON).
 Step-6: Optimize different parameters of the antenna to obtain optimal results.
 Step-7: Generate the resultant plots and values (S11,E and H plane Radiation pattern ,Gain , Directivity, Efficiency,
Front to Back Ratio , Current distribution ,Radiated power) to verify the performance of designed antenna at multiple
resonant frequency bands.
 Step-8: Fabricate the antenna and obtain the test results.
 Step-9: Compare the simulation results with the tested fabrication results.
 Step-10: Verify the antenna performance based on the comparison of simulation results with the tested fabrication
results.

SIMULATION STEPS IN HFSS:
1. Open HFSS insert HFSS design
2. Insert a substrate with required dimensions and assign FR4 epoxy material (∈=4.4)
3. Design the patch and ground structure on the same side of the substrate.
4. Assign the required boundaries to all parts of antenna .
5. Assign a lumped port to the feed line.
6. Insert the required radiation boundary such that it is λ/4 distance away from all outer surfaces
of the antenna.
7. Analyse and validate the antenna.
8. Obtain the resultant plots and values.

MINIMUM REQUIREMENTS OF PERFORMANCE PARAMETERS:
1. Return loss of antenna <= -10dB.
2. VSWR < 2.
3. Gain >= 3dB.
4. Radiation pattern of E and H field should be highly directional.
5. Radiation of antenna predominates in the Fresnel’s region ,which is the radiating near field of the antenna.
0.62
𝑑^3
λ
< r <
2𝑑^2
λ
d = maximum dimension of antenna
λ = wavelength
r = radius of the radiating sphere
6. In radiation pattern ,the major lobes must be predominant than the minor lobes.

IMPLEMENTATION:
ANTENNA DESIGN STEPS
STEP:1 STEP:2 STEP:3
STEP:4 STEP:5 STEP:6

STEP-1: Insert a box of length=35mm , width=40mm and height =1.6mm , which is defined as substrate.
STEP-2: Add a rectangle of with required dimensions, which is defined as ground.
STEP-3: Add 3 rectangles and unite them , to define a T shaped patch.
STEP-4: Add 2 more rectangles at required positions to create a slot.
STEP-5: Subtract the slots from the patch.
STEP-6: Insert two pin diodes in the slots.
STEP-7: Add a port to the T shaped patch.
STEP-8: Create a box inculcating antenna of dimensions larger than substate of antenna, which act as a radiation box.
STEP-9: Assign the required material, boundaries and excitation:
1. FR4 epoxy(ε =4.4) - substate
2. perfect E boundary - patch and ground
3. lumped port - port
4. lumped RLC - switches
5. Radiation boundary and air medium - Radiation box

ANTENNA DESIGN
TOP VIEW 3D VIEW
patch
substrate
port
Ground
switch

Parameter Value(mm) Parameter Value(mm)
L1 40 W1 35
L2 36 W2 25
L3 19 W3 2.5
L4 2 W4 3.06
L5 3 g1 1
L6 2 g2 1
L7 2 G1 16
DESIGN PARAMETERS OF THE PATCH AND GROUND :

PIN-DIODE(BAR50-02V):
 In this project we used two PIN diodes.
 The design of the PIN diode is based on RLC excitation values.
 The diode is operated in OFF state where Lf = 0.6nH , Cp = 0.15pF and parallel resistance Rp = 5Kohm and when
operated in ON state , Lf = 0.6nH and series resistance Rs = 3 ohms.
 As we used 2 pin diodes , 4 switching cases are possible
state Cp Rp Lf Rs
ON - - 0.6 nH 3ohms
OFF 0.15pF 5Kohms 0.6 nH -
D1 D2
ON ON
ON OFF
OFF ON
OFF OFF

PIN-DIODE SWITCHINGRESULTS:
CONDITION RESONANT
FREQUENCY
IMPEDANCE
BANDWIDTH
ON-ON 1.8 GHz 353 MHz
ON-OFF 5.75 GHz
8.62 GHz
1.1133 GHz
390 MHz
OFF-OFF 6.21 GHz 1.3186 GHz
OFF-ON 2.48 GHz
5.14 GHZ
570 MHz
193.7 MHz

DIODE STATE RESONANT
FREQUENCY(GHz)
FREQUENCY
BAND
FH (GHz) FL (GHz) BANDWIDTH(FH-FL)
ON-ON 1.8 L 2.0119 1.6186 353 MHz
ON-OFF 5.75
8.62
C
X
6.51
8.86
5.3967
8.47
1.1133 GHz
390 MHz
OFF-ON 2.48
5.14
S
C
2.784
5.2337
2.212
5.04
570 MHz
193.7 MHz
OFF-OFF 6.21 C 7.21 5.8914 1.3186 GHz
BANDWIDTH CALCULATION:
 Draw a horizontal line on to S11 curve at -10dB, it cuts the deep of the resonant frequency curve at 2
points called FH(high frequency) and FL(low frequency)
 BANDWIDTH = High frequency – Low frequency (FH-FL)

E-Plane Radiation Pattern
D1,D2=ON,ON: AT RESONANT FREQUENCY = 1.8GHz
H-Plane Radiation Pattern
 Obtained two major lobes in both E and H field radiation patterns
E-field: 22.15V/m at 0deg and 23.32V/m at 180deg
H-field: 21.13A/m at 270deg and 21.07A/m at 90deg

Vector Current Distribution
3D-gain plot of antenna
E-field Distribution
Obtained a maximum gain of 5.6dB

D1,D2 = ON,OFF : AT RESONANT FREQUENCY = 5.75 GHz
E-Plane Radiation Pattern H-Plane Radiation Pattern
H-field: 18.43A/m at 30deg , 18.01A/m at 135deg , 17.52A/m at 225deg , 18.37A/m at 330deg

D1,D2 = ON,OFF : AT RESONANT FREQUENCY = 8.62 GHz
 Obtained major and minor lobes in both E and H field radiation patterns
E-field: 16.5V/m at 330deg , 14.73V/m at 10deg , 12.85V/m at 60deg , 13.08V/m at 120deg ,14.54V/m at 160deg,
14.46V/m at 240deg
H-field: 17.36A/m at 20deg , 17.82A/m at 90deg , 18.74A/m at 150deg , 17.33A/m at 225deg, 15.27A/m at 225deg

D1,D2 = OFF,ON : AT RESONANT FREQUENCY = 2.48 GHz
H-field: 19.02A/m at 90deg , 18.88A/m at 270deg

D1,D2 = OFF,ON : AT RESONANT FREQUENCY = 5.14 GHz
 Obtained 2 major , 2 minor lobes in E field radiation pattern and 2 major lobes in H field radiation pattern
E-field: 11.41V/m at 60deg , 15.56V/m at 130deg , 19.47V/m at 220deg , 18.93V/m at 330deg.
H-field: 17.635A/m at 130deg , 17.63A/m at 220deg

D1,D2 = OFF,OFF : AT RESONANT FREQUENCY = 6.21 GHz
E-field: 13.01V/m at 60deg and 13.85V/m at 120deg,16.7V/m at 210deg , 18.75V/m at 340deg
H-field: 19.01A/m at 30deg , 19.09A/m at 130deg , 18.63A/m at 230deg , 18.99A/m at 330deg

REASONS FOR VARIATION OF THE RADIATION PATTERN IN 4 DIODE
SWITCHING CASES
 In general, the radiation pattern of an antenna is affected by a range of factors, including
1. the physical characteristics of the antenna
2. the frequency of the signal
3. By switching different elements using diodes
 In an antenna, diodes are often used as switches to switch different elements of the antenna on and off,
which can help to direct the radiation in a specific direction.
 When a diode is switched on or off, it can affect the current flowing through the antenna, and this can
affect the radiation pattern. Specifically, the diode switching can affect the phase and amplitude of the
electromagnetic waves radiated by the antenna.
 In a switchable beam antenna, when a diode is switched from a forward-biased state to a reverse-biased
state, the electric field within the diode can cause the charge carriers to be accelerated in the opposite
direction. This can result in the emission of radiation in a different direction than when the diode was in the
forward-biased state.

DIODE SWITCHING S11(REFLECTION
COEFFICIENT)
(dB)
IMPEDANCE
BANDWIDTH
RESONANT
FREQUENCY
(GHz)
FREQUENCY
BAND
GAIN
(dB)
DIRECTIVITY FRONT
BACK
RATIO
EFFICIEN
CY
RADIATED
POWER(W)
BAND
APPLICATIONS
ON ON -18.4457 353 MHz 1.8 GHz L 3.6324 2.24 1.3096 1.6216 1.5985 Bluetooth
ON OFF -38.2287
-13.3273
1.1133
GHz
390 MHz
5.75 GHz
8.62 GHz
C
X
1.5806
2.9854
1.8307
3.6549
1.9979
7.6014
0.8634
0.8168
0.8633
0.7788
WLAN
OFF OFF -29.0031 1.3186
GHz
6.21 GHz C 1.9467 2.1526 1.2347 0.9044 0.9941 WLAN
OFF ON -18.2855
-11.769
570 MHz
193.7
MHz
2.48 GHz
5.14 GHZ
S
C
2.5359
1.5903
2.5132
2.7222
1.394
6.0136
1.009
0.5842
0.5453
0.9032
Wi-Fi
WiMAX
ANTENNA WITH PIN DIODES RESULTS:
D1 D2

CONCLUSION:
 Measured results shows that the antenna exhibits frequency reconfigurability at four switching modes (ON-
ON,ON-OFF,OFF-ON,OFF-OFF) at six resonant frequencies 1.8GHz ,5.75GHz, 8.62GHz , 2.48GHz , 5.14GHz
and 6.21GHz.
 The antenna is operated at L,C,S and X band , exhibits almost omnidirectional radiation patterns both in E- and H-
planes.
 Due to the switching mechanism of the diode we obtained different radiation patterns in the 4 switching cases.
 The reflection coefficient (S11) is less than -10dB for all above frequencies which is a sign of better result.
 The gain obtained in the above frequencies are positive , it specifies the maximum input power is fed in a particular
direction.
 The resonant frequency range of antenna is used for the wireless applications like Bluetooth , WLAN, Wi-Fi and
WiMAX.

STATUS REPORT
WORK DONE:
 Antenna designing
 Analysed and verified antenna parameters
 Obtained frequency reconfigurability
 Obtained required plots and values through simulation in HFSS
WORK TO BE DONE:
 Antenna fabrication
Fabrication status : antenna structure is verified and will be fabricated within 10-15 days
 To obtain hardware results
 Comparison of hardware and simulation results

MULTIBAND reconfigurable antenna BATCH-5.pptx

�ݺ�ߣ

MULTIBAND reconfigurable antenna BATCH-5.pptx

Recommended

More Related Content

Similar to MULTIBAND reconfigurable antenna BATCH-5.pptx (20)

Recently uploaded (20)

MULTIBAND reconfigurable antenna BATCH-5.pptx