Integrated Front End Receiver for
S-DARS Reception(Satellite Digital Audio Radio Service)
Advisor
Dr. Thomas Weller
Senior Capstone Project
Final Report
University of South Florida
Electrical Engineering Department
Spring 2013
Team
“Wireless Moguls”
Peter Kowalik Yuriy Miroshnichenko
U13859596 U44023635
Table of ContentsIntroduction....................................................................................................................................................3
Design Requirements.....................................................................................................................................4
Electronical................................................................................................................................................5
Mechanical.................................................................................................................................................5
Miscellaneous............................................................................................................................................5
Design Specifications.....................................................................................................................................6
Solution......................................................................................................................................................6
Amplifier....................................................................................................................................................6
Antenna Design..........................................................................................................................................7
Constraints.................................................................................................................................................7
Test Plan Document.......................................................................................................................................8
Specific Test Plan Components.................................................................................................................8
Components to be Tested...........................................................................................................................8
Requirements Document Matrix................................................................................................................9
Antenna Design Considerations...................................................................................................................10
ADS Simulations.....................................................................................................................................11
Fabrication...............................................................................................................................................12
Alternative Antenna Designs.......................................................................................................................13
ADS Momentum Visualization Tool Simulation....................................................................................16
Fabrication of Patch Antenna...................................................................................................................17
Pre Selective Filtering..................................................................................................................................17
Band Pass Filter.......................................................................................................................................17
Amplifier Design.........................................................................................................................................18
Verification Measurements..........................................................................................................................18
Conclusion...................................................................................................................................................23
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Introduction
As engineers, one of our many duties is to be a part of the ever improving change and
innovation that drives this world. Electrical engineering is a particularly attractive field for this
reason, especially to individuals that have a burning desire to make an impact on history. Many
major modern contributions came from multi-disciplined engineers that took the initiative to seek
out opportunities to harness their knowledge in math, science, and engineering in new ways.
They see a need, a problem, a way to make something better, or more affordable, and use their
engineering abilities to find a solution. Successful application can oftentimes lead to more
opportunity, growth, and potentially, a large enterprise with virtually limitless reward to oneself
in all respects. This is the entrepreneurial spirit that influences many, including our group. Apart
from getting a great capstone learning experience, this was also one of the motives behind our
project. We saw an opportunity when we notices a large price and quality gap between two types
of antenna’s, so we felt it would be worth a try to use our expertise and multi-disciplinary
backgrounds to design a median product. Although like all, we also start from somewhat humble
beginnings, but we hope that this senior project will act as a stepping stone into our future,
inspiring us to take on greater engineering design projects, and other endeavors.
So more specifically, for our project we designed a front end receiver for commercial
SiriusXM radio. The three main modules of it are the antenna, bandpass filter, and a low noise
amplifier (LNA). The goal of the project was to get a working model and integrating the
components into our design to achieve a premium level of performance. Ultimately, we were
able to successfully build a comparable product of a premium front end receiver, and within our
budget limitations, allowing us to potentially offer it for a fraction of the price of the competitor.
This document will provide a overview of our design progress throughout the semester.
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RequirementsWe have seen over the years how technology is evolving around us and how the
capabilities of our devices such as cellphones have greatly improved in the past decade. The
other thing that has been evolving is the SiriusXM which gives you access to crystal clear radio
station no matter where you may be if you’re on a boat, in a car, or just listening to radio inside
your home. The great thing about Sirius radio is they have over 170 channels which is more than
you can get on your standard FM radio. The advantage of Sirius XM radio compared to such
radio systems as FM is that Sirius uses satellites orbiting in space to transmit the information to
earth where in FM you have towers set up in different places and you can easily loose signal of a
radio station by going to another city.
The problem that we were trying to solve by doing this project was to make an active
antenna to be able to connect it to a factory SiriusXM radio to receive the signal from satellites
and not have to spend as much as one hundred dollars if we were to buy a high grade antenna
from a store. In order to achieve this we have to follow the requirements that are going to be set
in this document to keep us on the right track and make sure that everything is considered
especially the needs of the customers that are going to use this front end receiver in there radio
setup.
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Electrical Specifications
2.0. The operational frequency of the Sirius XM antenna must be in the band of the Sirius
spectrum which is 2320MHz to 2345MHz.
2.1. The voltage standing wave ratio (VSWR) must be below 3:1 or Better.
2.2. The input impedance of the antenna must be 50 Ohms.
2.3. The LNA should have a gain of 28 dB.
2.4. The antenna must be left hand circular polarization (LHCP).
2.5. The antenna without the LNA should have at least unity gain.
2.6. Input connector TNC Female.
2.7. Voltage input 3~5V
2.8. Current drawn by the LNA should be no more than 30ma
Mechanical Specifications
3.0. The overall weight of the active antenna must not exceed half of a pound
3.1. The dimensions should not exceed 3″x3″x2″.
3.2. The antenna must be water proof.
3.3. The antenna must have a magnet to be easily attached to a cars roof.
Other Requirements
4.0. The antenna should not cost us more then $30 to build final design.
4.1. The antenna needs to work with Sirius radios that are currently in use.
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Specifications
Introduction
In our project we are trying to achieve a left hand circular polarized antenna that will be
connected to the Low noise amplifier and receive satellite signal which will then play music in
your car from factory Sirius radio. The problem that we are trying to solve is to design the
antenna and a low noise amplifier circuit that we will put together to get us the proper gain and a
good radiation pattern of the antenna to achieve a good connection between our antenna and the
satellites.
Solution
For our low noise amplifier we have built a circuit to compliment the mini circuits PSA-545+
which is a high gain and a low current that we need to have in our amplifier design. The Gain
that we measured of our or amplifier circuit was around 18dB of gain. The antenna we have not
built yet but we have many approaches that we can take on the antenna design the different types
of antennas that we could built is a Quadrifilar Helix, turnstile, or patch fed 90 dugout phase.
Schematic of our Amplifier Design
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Antenna Design Implementation Attempts(by type)
Quadrifillar Helix Turnstile Antenna Patch Antenna
Constrains
Parts availability could be an issue and getting them on time also the level of knowledge and
experience that we have in our group. We also noticed that we don’t always get to use the Wami
lab which has a limited amount of open hours so that we could accomplish all of our testing.
Conclusion
We have already started putting our project together and have seen positive results. Therefore we
think we have all the proper mentality and knowledge that we need to complete this project. As
of now we have a working low noise amplifier circuit and need to do more testing.
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Test Plan Document
Objectives
The objective is to test our Sirius XM active antenna and verify that it is working to the
specifications of our designed. Our intention to do this testing as we build our project and make
sure that we stay within our requirements that we have set forth in the beginning of our design
process in the requirements document.
Testing Strategy
The strategy that we want to take is to build our components separately because of the
complexity of the project we need to test our components separately to be able to get the required
testing done and then combine the components to build the complete active antenna. The testing
is going to be done in several steps after the components are built they will be tested and verified
to be working to the specifications in this document.
Specific test plan components:
Low Noise Amplifier
Frequency of amplification (2.0)
Gain 28 dB (2.3)
Voltage Input 3~5V (2.7)
Current drawn < 30mA (2.8)
Antenna
Operational frequency 2,320~2,345MHz (2.0)
VSWR 3:1 or Better (2.1)
Input impedance 50Ω (2.2)
Polarization LHCP (2.4)
Antenna must have at least unity gain (2.5)
Input Connector TNC Female (2.6)
Components tested
Low Noise Amplifier
Antenna
Bandpass Filter
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Approach
The Low Noise Amplifier is going to be tested using a Vector Network Analyzer to verify the
gain of the amplifier at the desired frequencies. The current drawn by the amplifier is going to be
checked with a Voltmeter. In order to do our testing on the antenna we can use a vector network
analyzer to determine that it is performing to our specifications, we also intent to do radiation
patterns of our antenna to verify that we don’t have any nulls in our patterns that might affect the
signal strength at critical angles.
Requirements Document MatrixElectrical Specifications2.0. The operational frequency of the Sirius antenna 2320MHz to 2345MHz.2.1. The voltage standing wave ratio (VSWR) must be below 3:1 or Better.2.2. The input impedance of the antenna must be 50 Ohms.2.3. The LNA should have a gain of 28 dB.2.4. The antenna must be left hand circular polarization (LHCP).2.5. The antenna without the LNA should have at least unity gain. 2.6. Input connector TNC Female. 2.7. Voltage input 3~5V 2.8. Current drawn by the LNA should be no more than 30mAMechanical Specifications3.0. The overall weight of the active antenna must not exceed one pound3.1. The dimensions should not exceed 3″x3″x2″.3.2. The antenna must be water proof. 3.3. The antenna must have a magnet to be easily attached to a cars roof. Other 4.0. The antenna should not cost us more than $30 to build final design.4.1. The antenna needs to work with Sirius radios that are currently in use.
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Antenna Design
For the antenna design we needed to make a left hand circularlypolarized
antenna(LHCP), we were suggested to try and make a patch antenna with two feedlines and
feed one 90 degree out of phase. The patch antenna was used because we were only working
with a percentage bandwidth of 1% and it is a good starting point for our project. By using a
5mm air gap in our design we could easily achieve the bandwidth of 25 MHz. This antenna
design was made using the Advance Design System (ADS).
Design parameters
For this design we calculated the following parameters for our antenna using Linecalc the
parameters for are antenna are listed below (table1).
Center
Frequenc
y
(MHz)
Dielectric
constant
Width of
Feedline
Width
of
Patch
(mm)
Length
of
Patch
(mm)
Wavelength
,λ (mm)
Wavelength
,λ/2(mm)
Wavelength
,λ/4 (mm)
2332.5 4.3 3.08 30 35.5 70.97 35.49 17.43
Table 1
Simulated antenna in (ADS)
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Usingthe parameters described above, simulations in Momentumwere performed.The results
areshown in Figures.1 through 6
Figure 1. Patch Design Figure 2. |S11| simulation of patch antenna
Figure 3.Axial Ratio Figure 4. Smith chart
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PowerGain Directivity
-90°
0°
90°
180°
-34
-24
-14
-4
6
-44
16
THETA (-90.000 to 90.000)
Mag.
[dBi]
Figure 5. Simulated power 3dBi Figure 6. Simulated polarization of antenna
Fabricated Antenna
The antenna wasfabricated using 60 mil FR4 substrate with a 5mm air gap shown in Figure 7.
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Figure 7.Fabricated Antenna
Conclusion
This antenna design showed a good frequency response in the band of interest. Some of
the things observed for this design there was a sharp increase in the axial ratio in this antenna
after 30 degrees from the boresight of the antenna and a lower than expected gain of 3dBi. After
seeing that this was not the most optimum design to be utilized in our front end receiver we
decided to still make a patch antenna but utilize a different design using a single feed point with
perturbed edges.
Alternative Antenna Design
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For this antenna design simply by adjusting the feedline offset away from the center of
the patch LHCP can be achieved and a good axial ratio can be attained byadjustingthe patch
widthandlength.Itwasfoundin simulationsthat the line insetdoes not havea significanteffect on the
axial ratio. Since the AR could notbesimulated to be below 1dB bychangingallgeometrical
parameters and changing substrate thicknesses and dielectricconstants, a new
designwasconsidered because the overall axial ratio of the new antenna design was better than
the first approach with two feed lines to the patch this design was chosen to be used in the final
design of the front end receiver. The use of a perturbrectangularpatch with opposite diagonal
corners truncated in our design helps to separate theorthogonalmodes and allow for LHCP
Figure 8.
Simulated antenna in (ADS)
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2.325 2.330 2.335 2.3402.320 2.345
-15.1-15.0-14.9-14.8-14.7-14.6
-15.2
-14.5
Frequency
Mag.
[dB]
S11
Figure 8. Patch antenna design Figure 9. |S11| Simulation of patch antenna
Axial Ratio
-80 -60 -40 -20 0 20 40 60 80-100 100
5
10
15
20
25
30
35
40
45
0
50
THETA
Mag.
[dB]
freq (2.320GHz to 2.345GHz)
S11
Figure 10. Axial Ratio Figure 11. Smith Chart
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PowerGain Directivity
Efficiency [%]74.981
m1THETA=10*log10(mag(Gain))=6.550
0.000
-135°
-90°
-45°
0°
45°
90°
135°
180°
-31
-21
-11
-1
-41
9
THETA (-90.000 to 90.000)
Mag
. [dB
i]
Readout
m1
m1THETA=10*log10(mag(Gain))=6.550
0.000
Circular PolarizationE_left E_right
-135°
-90°
-45°
0°
45°
90°
135°
180°
-40
-30
-20
-10
-0
-50
10
THETA (-90.000 to 90.000)
Mag.
[dB]
Figure 12.Gain of Simulated patch is 6.55dBi Figure 13.Simulated polarization
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ADS Momentum Visualization Tool Simulation
Isometric view
Side view
Figure 14.ADS visualization tool simulates E fields in patch design
Looking at the simulation in ADS Visualization we can see that the electric field rotates counter
clock wise which verifies the Left Hand Circular polarization that we are trying to achieve in our
design.
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Fabrication of Patch Antenna
Figure 15.fabricated patch antenna
Conclusion
The new design of the patch antenna we were able to accomplish a higher gain and a
better axial ratio of the antenna then the first design. The final parameters for the antenna that
gave us the best result of return loss, axial ratio, and exhibit a left hand circular polarized
radiation was 120 mils of FR4 substrate with a 60mils air gap.
Pre Selective Filtering
Band pass filter
For this project is it crucial to use a bandpass filter in our design so we can filter
unwanted signals that are outside our band. Looking at (Figure 16) we can see response
ofbandpass filter over the frequency’s ranges. This filter covers the necessary band for our front
end receiver and has an insertion loss less than 1.5 dB over the range of the filter bandwidth.
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Figure 16. Response of Bandpass Filter
Amplifier Design
The LNA amplifier used in our front end receiver system is a mini circuits 545 chip
amplifier. In integration of the amplifier in our design we had to set the bias voltages to the
amplifier and connect the 5V DC source to the amplifier that is delivered from the radio units
connector also had to use capacitors at the input and the outputs of the amplifier to block the DC
signal from damaging our amplifier.to verify the gain of the LNA we used a network analyzer
and measured the gain of our LNA to be 18 dB.
Verification Measurements
We wanted to verify the actual gain of the fabricated patch antenna and see if it was close to the
simulated gain in ADS. The way we measured gain is we used gain by comparison. We set up
our test by setting the vector network analyzer to S21 measurement and used a horn antenna for
the transmit antenna and our calibrated reference antenna was a high gain horn which has a 10
dBi gain at the frequency of interest 2320 to 2345 MHz The measured gain in lab was plotted in
excel shown in[Figure 17].
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2320 2325 2330 2335 2340 23453
3.54
4.55
5.56
6.57
Measured Gain of Patch Antenna
Frequency (MHz)
Gain
(dBi
)
Figure 17. Measured Gain
Figure 18. S21 responses of gain measurement
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Figure 19. Gain by Comparison Measurement
For the verification process of our final design test we set up a vector analyzer as our signal
generator using a horn antenna as a transmit antenna and connected the front end receiver to the
spectrum analyzer and measured the signal that was received by the front end receiver from the
network analyzer source in dBm. for this experiment we wanted to measure different type of
front end receivers to see how our design compared to other front end receivers. The transmitter
and the front end receiver were places 1 meter apart during this measurement to see power level
measured of different front end receivers measured[Figure 20].
Figure 20. Power measurement of front end receiver
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Figure 21.Premium Sirius front end receiver power measured 2.31 dBm
Figure 22. Power measured of our antenna and evaluation board LNA of -1.93 dBm
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Figure 23. Power measured of our antenna and LNA of -5.22dBm
Figure 24. Power measured of standard front end receiver of -11.06 dBm
With this test we were able to confirm the performance of different front end receivers
compare to our design. With the use of evaluation board we go the best result compared to the
premium antenna and our front end receiver design showed a lower gain then the premium front
end receiver so the LNA that we designed did not meet the objective gain for the overall design
of the front end receiver. We suspect that we might have a problem with our components in the
LNA design because of the frequency that we are working with the components could be more
inductive or capacitive at high frequency.
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Conclusion
We were able to design and build a fully functioning front end receiver to successfully
accept a SDARS signal. A video may be viewed of the working model on our YouTube page
found on our website: www.wirelessmoguls.wordpress.com. After a semester’s worth of trial and
error attempts, we were finally able to achieve specifications closed to our desired. That
drawback was due to the fact that there was a little less gain at the amplifier. However, we still
achieved making it a product worthy to bring to market and potentially make larger quantities of,
as we hoped originally. Our objective to develop a front end receiver with specifications similar
to the premium brand was met using the evaluation board of our amplifier design it shows that
with correcting our amplifier design the objective would be met and built for a fraction of the
cost of premium front end receivers. We also learned more about the science of integrating
components and the process building a whole system. We got practical experience designing and
developing a wireless device from scratch, which can be very valuable in the industry. It
wouldn’t have been possible without our teamwork and each member’s multidisciplinary
backgrounds. This was a very challenging senior design project. It bought together all of the skill
we’ve acquired throughout our college experience at USF. Overall, this was a great capstone
experience!
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