x-band nanosatellite telecommunication system design
TRANSCRIPT
X-Band Nanosatellite
Telecommunication System Design
Master student: AL-SALIHI IBRAHEEMALKHALIL EMAD KHUDHUR
Samara 2020
Supervisor: Associate professor I.A. Kudryavtsev
Master thesis
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Contents
1. Relevance and the goal of the thesis.
2. Analysis the telecommunication system performance.
a) Simulating an X-Band telecommunication system.
i. Orbital selection.
ii. Telecommunication components.
iii. Link budget calculation.
b) Formulate the requirements of the antenna to improve the X-Band telecommunication system.
3. Microstrip patch antenna review.
4. Antenna design and simulation.
a) 1st step: tuning the antenna parameters.
b) 2nd step: Obtaining the circular polarization.
c) 3rd step: Improve antenna performance by using parasitic patch technique.
d) 4th step: Improving the antenna by using reflector technique.
e) 5th step: Improving the antenna performance by using an additional parasitic patch.
5. Re- simulation the telecommunication system.
6. Conclusion.
X-Band Nanosatellite telecommunication system Design
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Relevance and the goal of the thesis
In Nanosatellite there are many limitations affect the link connection between the Nanosatellite and ground
station:
1- link reliability depends on distance and path loss for x band frequencies is more significant.
2- Number and dimensions of the solar panels are limited which influence the quantity of the power can be
absorbed from the sun(β2W), which also effects on the power can be generated to the communication system
and payloads
3- Time connection is about few minutes due to the high-speed movement of the Nanosatellite.
Also, there are other factors such as type of modulation techniques and coding methods that affect the
performance of the X-band telecommunication system of the nanosatellite.
Our goal is to develop an X-Band telecommunication system for Nanosatellite by designing and simulating antenna to satisfy the
requirements of telecommunication system enhancement.
Figure1- Nanosatellite
telecommunication system
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Analysis the telecommunication system performance
a) Simulating an X-Band telecommunication system.
i. Orbital selection.
ii. Telecommunication components.
iii. Link budget calculation.
b) Formulate the requirements of the antenna to improve the X-Band telecommunication system.
Our mission selected to perform a short-term earth observation that required high data rate.
The circular orbit selected for the mission is the low Earth orbit (LEO) with an altitude of 300 km.
i. Orbital selection
Orbital shape Circular orbit
Orbital position Low earth orbit (LEO)
Height of apogee (ha) 300 km
Height of perigee (hp) 300 km
Semi major axis (a) 6678 km
Eccentricity (e) 0
Inclination (I) 98.61Β°
Table 1 - Orbital parameters
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Analysis the telecommunication system performance
Figure 3 - Micro X-Band HDR-TM transmitter
Figure 2 - ASC Signal 7.6m C & X-Band Low PIM Tx/Rx Earth Station Antenna
Transmitter specification
Dimension 96Γ90Γ24 (ππ3)
Operation frequency X-Band-(8025-8400) MHz
Data rate From (2.8 to 50) Mbps up to 100 Mbps
Modulation type Offset-QPSK
Power consumption <7 W for 1W RF output powerΒ·
< 10W for 2W RF output power
Eb/N0 2.7 dB
BER 10E-9
Mass 300 g
Applications Earth observation
RF output power 30 β 33dBm, with 1-dB step
Table 3 - Transmitter specifications
Ground station specification
Antenna type Parabolic reflector antenna
Antenna diameter 7.6 m
Hub/Enclosure Dimensions: Diameter 1.33 m, depth 1.17 m
Frequency band receive (7.5 - 8.4) GHz
Antenna gain 54.7 dBi
Polarization circular polarization
Axial-Ratio 1.2 dB
Beam width 0.3Β°
Tx power capacity 750 W
Table 2 - Ground station specifications
ii. Telecommunication components
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Link budget calculation
elevation angle(πΏ) 5Β°
Slant Range (π) 1499.5 km
Center frequency (downlink) 8.142 GHz
BER 1 Γ 10β9
Eb/N0 2.7 dB
Data rate 2.8 Mbps
Power of transmitter 1.5 W
Assumed Antenna gain of nanosatellite 5 dBi
Ground station Tx Power 750 W
Gain of ground station 54.7 dBi
BW of ground station receiver 30.5 MHz
DL. link margin (πΈπ/π0 method) 11.8 dB
DL. link margin (πππ method) 1.4 dB
Table 4 - Simulation X-Band telecommunication system
iii. Link budget calculation
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Nanosatellite antenna requirements
Microstrip patch antenna requirements
Dimensions Less than 100Γ100Γ20 (ππ3)
Operation frequency X-Band
Feeding Coaxial feed
Impedance 50 πΊ
Polarization Circular polarization
Bandwidth >150 MHz
Gain More than 8 dBi
Beam width Less than 35Β°
S-Parameter Less than minus 10 dB
Table 5 - Nanosatellite antenna requirements
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Microstrip patch antenna review
Microstrip patch antenna specifications
Dimensions 25.95 Γ 25.95 Γ 1.575
(ππ3)
Operation frequency 10 GHz
Feeding Coaxial feed
Polarization Circular polarization
Gain 7.64 dBi
S-Parameter ~ - 13 dB
Table 6 β 1st review Nanosatellite antenna
specifications
1st review Nanosatellite antenna
Wayan Suparta, Mardina Abdullah, Mahamod Ismail, Space Science and Communication for Sustainability, ISBN 978-981-10-6574-3, Library of
Congress Control Number: 2017952532, Springer Nature Singapore Pte Ltd. 2018
Figure 5 β Gain of the 1st reviewed antenna Figure 4 -Antenna integrated with the 1U satellite
body
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Microstrip patch antenna review
Microstrip patch antenna specifications
Dimensions 24 Γ 24 Γ 2.3 (ππ3)
Operation frequency 8.2 GHz
Feeding Coaxial feed
Polarization Circular polarization
Gain 6.5 dBi
S-Parameter ~ - 30 dB
Table 7 β specifications of the 2nd reviewed
Nanosatellite antenna
2nd review Nanosatellite antenna
Figure 7 β radiation pattern of the 2nd reviewed
antenna
Figure 6 - front view of the X-Band Single
Element Patch Antenna
EnduroSat's X-BAND SINGLE ELEMENT PATCH ANTENNA
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Design and simulation process of patch antenna
1st step: tuning the antenna parameters
Radius of The Patch (mm) 11.5
Thickness of The Patch (mm) 0.035
Size of The ground (mm*mm) 50Γ50
Thickness of The Ground (mm) 0.035
Size of The Substrate (mm*mm) 50Γ50
Thickness of The Substrate (mm) 0.8
Table 8 - parameters of the antenna
Theoretical calculation
πΉ =8.791Γ109
ππ ππ= 0.529
π =πΉ
1+2β
ππππΉln
ππΉ
2β+1.7726
1/2 β 0.53 cm
ππ = π 1 +2β
ππππln
ππ
2β+ 1.7726
1/2β 0.9 cm
Figure 8 - Front view of the 1st step antenna structure
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Antenna design and simulation
Figure 9 - The antenna structure of the 2nd step
2nd step: Obtaining the circular polarization 3rd step: Improve antenna performance by using stacked parasitic patch technique
Figure 10 - Antenna dimension of the 3rd step
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Antenna design and simulation
Figure 11 - The antenna structure of the 4th step: (a) Front view with dimensions, (b) Side view with dimensions
(b)(a)
4th step: Improving the antenna by using reflector technique
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Antenna design and simulation
Figure 12 - Front view of the 5th step without 2nd substrate
5th step: Improving the antenna performance by using coplanar parasitic patch technique
Figure 14 - S-Parameters of the final simulationFigure 13 - Far-field of the final simulation
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Antenna design and simulation
Desired results Achieved results
Dimension < 100Γ100Γ20 (mm^3) Dimension 66Γ66Γ15 (mm^3)
Operation frequency X-Band Operation frequency X-Band
Feeding Coaxial feed Feeding Coaxial feed
Impedance 50 Ξ© Impedance π11 = 45.7 Ξ©
π21= 49.9 Ξ©
Polarization Circular polarization (AR < 3 ππ΅) Polarization Circular polarization (AR = 0.26 dB)
Bandwidth More than 150 MHz Bandwidth 200.98 MHz
Gain More than 8 dBi Gain 11.1 dBi
Beam-width < 35 degrees Beam-width 29.9 degrees
S-Parameter Less than -10 dB S-Parameter π11 = - 28 dB
π21 = -60.323 dB
Table 9 - Comparison between desired results and achieved results
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Antenna design and simulation
Figure 15 β Antenna structure mounted on 3U CubeSat: (a) front view, (b) side view
(a) (b)
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Re - simulation the X-Band telecommunication system
elevation angle(πΏ) 5Β°
Slant Range (π) 1499.5 km
Center frequency (downlink) 8.142 GHz
BER 1 Γ 10β9
Eb/N0 2.7 dB
Data rate 6 Mbps
BW of ground station receiver 30.5 MHz
Power of transmitter 1 W
Assumed Antenna gain of nanosatellite 11.1 dBi
Ground station Tx Power 750 W
Gain of ground station 54.7 dBi
DL. link margin (πΈπ/π0 method) 13.3 dB
DL. link margin (πππ method) 6.2 dB
Table 10 - Re-Simulation X-Band telecommunication system with the usage of the designed antenna
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Conclusion
As it can be seen from simulation results that the X-Band telecommunication systemdeveloped by designing patch antenna which is satisfy developing requirements interms of:
β’ Enhancing the data rate from (2.8 Mbps) to (6 Mbps).
β’ Reducing the power consumption of the transmitter from (1.5 W) to theminimum (1 W).
β’ Increasing the link budget from (πΈπ/π0method = 11.8 dB, SNR method = 1.4 dB)to become (πΈπ/π0 method = 13.3 dB and SNR method = 6.2 dB).
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