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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