Transcript DSB Satellite Receiver System

Presented By: Sarah Scharf, Pierre Desjardins,
GuiPing Zhang, Peter Eseraigbo
Supervisor: Prof. Barry Syrett
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Operates in Ku Band 12-18GHz
Design is based on Bell Satellite Receiver
As of 2010 Bell TV had over 2 million satellite
customers
DBS Receiver
http://sonamjourno.blogspot.ca/2012_09_01_archive.html
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Receivers are used in all communication
systems
◦ Cellular communication
◦ Military radar and navigations systems
◦ Television broadcasting
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Opportunity to develop design skills which
are directly applicable to the communication
industry
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Opportunity to create a basic receiver design
and look for possible improvement
suggestions
This receiver design can be used by future
students to investigate more efficient and
cheaper receiver design options
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Diagram of our system:
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Each individual was assigned a component to
research and design
Conducted weekly group meetings
Met with supervisor on an as-needed basis
Communicated both verbally and through
email frequently
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Pierre: Antenna system and band-pass filter
◦ Reflector dish and Antenna feed
Name
Expected
Results
Antenna Gain
34.5dBi
32.77dBi
3dB Beamwidth
3.5deg
4deg
10dB Beamwidth
5.5deg
6deg
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Band-Pass Filter (12.25GHz -12.75GHz)
Gui: the two stage LNA is designed with
microstrip transmission line and used
pseudomorphic high-electronmobility transistors. The designed
gain is 20 dB and noise figure is lower
than 2 dB.
Using ADS software;
 Designed with Microstrip transmission
lines instead of lump elements.
 Started from Stage one with lower
noise figure and then second stage
with high gain.
 Optimized gain, noise figure and
stability in ADS environment.
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How to maintain the circuit stability at the
meantime achieving enough gain;
Solution is by make a compromise between
gain and stability
The minimum
specified gain for
this LNA is 20 dB
It only has lower than 2 dB noise figure.
And the circuit is stable
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This two stage LNA is expected to produce
the required gain
Peter: 11.25 GHz Dielectric Resonator
Oscillator (DRO)
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Primary purpose of the oscillator is to generate and maintain a
needed waveform at a constant amplitude and specific frequency
Antenna
IF = LO - RF
MIXER
IF
Filter
Signal
Processing
IF
RF
LO
BPF
LNA
LO = Local Oscillator
IF = Intermediate
Frequency
RF = Radio Frequency
OSCILLATOR
LO = 11.25 GHz
RF = 12.5 GHz
IF = 1.25 GHz
LO = 11.25 GHz
Methods and Techniques
Circuit Topology
Topology uses a resonator
coupled to microstrip line,
functioning as a high-Q bandstop
filter that couples a portion of the
transistor output back to its
input.
Matching Network
Series Feedback
DRO
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Advantages of topology
Very high unloaded Q (Several
thousand)
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lumped elements are limited to few
hundred
Low phase noise (Better)
Good output power
Excellent temperature stability of
material they are made from
Simulation done
using large signal
simulator –
Harmonic Balance
Parallel Resonant
Circuit with
transformer coupling
Active Device (BJT)
Matching Network
Circuit Shematic Series Feedback DRO circuit in ADS
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Getting oscillator to oscillate
◦ Adding current pulse
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Achieving desired oscillation frequency
◦ Investigating what circuit components affect
oscillator frequency.
◦ Trial and Error. Changing LC values and resimulating until oscillation frequency was achieved.
Results
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Sarah: Active BJT Mixer
◦ Methods and Techniques
• BFU710 by NXP selected as active mixer
component
Chosen mixer topology
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Challenges and Solutions
I-V curve for
BJT showing
approximate
bias point
Mixer starting point
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Results and Discussion
Approximate
layout
Output Spectrum:
Output voltage at 1.25 GHz
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Chosen and purchased active components
Design using ADS and HFSS
Simulation of design
Design layouts completed
Send out layouts for manufacturing
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Complete and test individual printed circuits
Complete second iteration of design and
manufacture if necessary
Present final result in written report
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Please stop by our poster for further technical
details.
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http://www.digitalhome.ca/2011/02/average
-bell-tv-subscriber-spends-75-a-month/
http://www.dbsinstall.com/GeneralInfo/Satell
ite_TV_Frequency_Bands.asp
http://www.hpl.hp.com/hpjournal/98feb/feb
98a6.pdf
http://elcodis.com/parts/421841/ATF36163-BLKG.html