The document describes a student project to design, simulate and fabricate a printed Yagi-Uda antenna. Key aspects of the project include determining antenna design parameters, optimizing the antenna design through simulation, and testing a fabricated prototype antenna. Simulation results showed a gain of 6.9 dB, return loss below -10 dB, and beamwidth of 76 degrees. Measured results of the fabricated antenna met specifications with a gain of 6.18 dB, return loss below -10 dB, and bandwidth of 525 MHz.

1. Project Title:
Design,SIMULATION& FABRICATIONOFPRINTED
YAGI-UDAANTENNA
BY:
AMIT GUPTA &
BAKSHI HARSHPREET SINGH
B - T E C H ( S E M E S T E R V I I )
B H A R A T I V I D Y A P E E T H U N I V E R S I T Y ,
C O L L E G E O F E N G I N E E R I N G , P U N E
EXTERNAL GUIDE
Mr EZHARUL ANSARI
SC. ‘C’, DLRL
HYDERABAD
INTERNAL GUIDE
PROF. BRIG (RETD.)
R.M. KHAIRE
Head, Dept. of E&TC
B.V.U.C.O.E,
PUNE

2. Outline of Presentation
 Overview
 Specifications
 Approach
 Design and Analysis
 Simulation Study
 Fabrication
 Results
 Future Roadmap
 Conclusion

3. Overview
Aim of the Project:
The aim of the project is to design, carry out simulation study and fabricate a
PRINTED YAGI UDA ANTENNA.

4. Specifications
Parameter Specifications
Frequency Range 4.0 GHz - 4.4 GHz
Gain 6 dB
Beamwidth Min 70o in both planes
Return loss Better than 10dB
Polarization Linear
Connector type SMA Tab type
Physical Dimensions 50x70 (mm)
Weight < 100g

5. Approach
 Literature survey:
 Antenna fundamentals
 Types of Antennas
 Antenna Parameters
 Determination of Antenna Design Parameters
 Modeling
 Simulation
 Optimization
 Fabrication
 Testing

6. Design And Analysis
Directors
Top Radiating element
Bottom
Radiating
Ground Plane or
Reflector
Substrate
Top
Bottom

7. Design and Analysis
 A Dipole, is chosen, as the radiating element to obtain Linear Polarization.
 Three directors and one reflecting element are used, to obtain the desired
gain and return loss.
 Rogers RT Duroid 5880 substrate board having a dielectric constant 2.2 was
used in our project. This is chosen because, lower the dielectric constant, more
will be the propagation of the EM Waves through the substrate. Hence a low
dielectric constant substrate is chosen.
 Its thickness is kept to be 0.8mm and the perfect electric conductors are
Copper.
 The feed line used is a microstrip line having a thickness of 4.8 mm, which
matches the input impedance of the antenna and the feed.

8. Design and Analysis
Calculated (Theoretical Dimensions):
PARAMETERS FORMULA CALCULATED VALUES (in mm)
Distance between
Reflector and Dipole
0.2λ-0.35 λ 14.2-24.85
Distance between the
successive directors
0.2 λ -0.35 λ 14.2-24.85
Width of Dipole 0.015 λ -0.025 λ 1.06-1.7
Width of Directors 0.015 λ -0.025 λ 1.06-1.7
Length of Radiating
element
0.45 λ -0.49 λ 31.95-34.79
Length of directors* 0.4 λ -0.45 λ 28.4-31.95
* The successive directors were reduced in size by 85%

9. Simulation Study
Perfect Electric Conductors

10. Simulation Study
Excitation (Waveport)

11. Simulation Study
Radiation Box

12. Parameter Optimization
The Optimized Parameters are listed in the table given below:
PARAMETERS FORMULA CALCULATED VALUES (in mm)
Theoretical
(in mm)
Optimized
(in mm)
Distance between
Reflector and Dipole
0.2λ-0.35 λ 9.4-16.45 10.55
Distance between the
successive directors
0.2 λ -0.35 λ 9.4-16.45 D1-D2 = 9.60
D2-D3 = 8.45
Width of Dipole 0.015 λ -0.025 λ 0.7-1.1 1.5
Width of Directors 0.015 λ -0.025 λ 0.7-1.1 1.5
Length of Radiating
element
0.45 λ -0.49 λ 21.15-23.03 30.0530
Length of directors* 0.4 λ -0.45 λ 18.8-21.15 D1=23, D2=18.2, D3=15.6

13. Simulation Results
Parameter Specifications Result
Frequency Range 4-4.4GHz 3.9-4.4 GHz
Bandwidth 400 MHz 500 MHz
Return loss Less than 10dB Less than 10 dB
Gain 6 dB 6.9dB
Beamwidth 70o 76o
Polarization Linear Linear
Physical Dimension 50mmX70mm (max) 48.6mmx66.4mm
Weight Less than 100g -

14. Simulation Results
GAIN/ RADIATION PATTERN
Gain = 6.9dB
-10.00
-5.00
0.00
5.00
90
60
30
0
-30
-60
-90
-120
-150
-180
150
120
HFSSDesign1Radiation Pattern 4 ANSOFT
Curve Info
dB(GainTotal)
Setup1 : LastAdaptive
dir='-5.412mm' dirl='26mm' Freq='4.2GHz' Phi='0deg'
dB(GainTotal)
Setup1 : LastAdaptive
dir='-5.412mm' dirl='26mm' Freq='4.2GHz' Phi='90deg'

15. Simulation Results
Return loss as obtained after the Simulation Study is shown below:
RETURN LOSS
-17.68 db
3.90 4.00 4.10 4.20 4.30 4.40
Freq [GHz]
2.50
3.75
5.00
6.25
7.50
8.75
10.00
dB(VSWR(1))
HFSSDesign1XY Plot 2 ANSOFT
Curve Info
dB(VSWR(1))
Setup1 : Sw eep
dir='-5.412mm' dirl='26mm'

16. Simulation Results
The variation in Gain and Return loss of the Antenna by the successive addition of Directors is
depicted below:
Elements Gain (dB) at 4.2 GHz Return Loss
Director 1 5.736 Resonant Freq: 4.3 GHz
Peak : -17.86 dB
Director 1 and 2 6.5118 Resonant Freq: 4.2 GHz
Peak : -18 dB
Director 1, 2 and 3 6.9056 Resonant Freq: 4.2 GHz
Peak : -18.74 dB

17. Results of Fabricated Antenna

18. Results of Fabricated Antenna

19. Results of Fabricated Antenna

20. Results of Fabricated Antenna
Frequency
(GHz)
Gain
(dB)
Beamwidth in HP
(degree)
Beamwidth in VP
(degree)
4 4.22 69.39 120.74
4.1 5.99 67.24 116.58
4.2 6.18 65.33 111.35
4.3 6.14 65.85 107.15
4.4 6.74 66.66 100.11
4.5 7.36 65.75 94.40
4.6 6.56 63.19 92.01

21. Results of Fabricated Antenna
A return loss of -43.954 dB is measured, which is resonant at a frequency of 4.39GHz. Its value is
below the -10 dB mark in a bandwidth of 525 MHz over the range 4.1 GHz to 4.625 GHz.

23. Comparison between the specifications,
simulated and measured results
Parameter Specifications Results
Simulated Realized
Frequency Range 4-4.4GHz 3.9-4.4 GHz 4.1 GHz-4.6GHz
Bandwidth 400 MHz 500 MHz 525 MHz
Return loss Less than 10dB Less than 10 dB Less than 10 dB
Gain 6 dB 6.9dB 6.18 dB
Beamwidth 70o 76o 65 o
Polarization Linear Linear Linear
Physical Dimension 50mmX70mm (max) 48.6mmx66.4mm 48.6mmx66.4mm
Weight Less than 100g Less than 100g Less than 100g

26. Key Inferences
The total length of the dipole determines the frequency of operation of the antenna.
The length and frequency are inversely proportional.
The reflector size and spacing have negligible effect on the forward gain and large
affects on the backward gain and input impedance.
The size and spacing of the directors has a large effect on the forward gain, backward
gain and input impedance.
More than one reflector provides little improvement on the directivity of the antenna.
The addition of more directors will increase the gain of the antenna, although after
the addition of approximately 5 directors the advantages of adding more directors
decreases significantly.

27. Future Roadmap
The Antenna may be assembled and used for its intended applications, in
defence or satellite communication, if the required Gain is 6-7 dB and Return
loss is below 10 dB.

28. Conclusion
The Yagi Uda antenna for the specified parameters is successfully
modelled, simulated, and fabricated to obtain the aimed
specifications.