1. DBS Receiver System
Presented By: Sarah Scharf, Pierre Desjardins, GuiPing Zhang, Peter Eseraigbo
Supervisor: Prof. Barry Syrett

2. Overview and Background
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

3. Motivation Receivers are used in all communication systems
Cellular communication
Military radar and navigations systems
Television broadcasting
Opportunity to develop design skills which are directly applicable to the communication industry

4. Significance of Project
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

5. Satellite Receiver System
Diagram of our system:

6. Project Management
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 frequently

7. Roles and Responsibilities
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

8. Roles and Responsibilities (con’t)
Band-Pass Filter (12.25GHz GHz)

9. Roles and Responsibilities (con’t)
Gui: the two stage LNA is designed with microstrip transmission line and used pseudomorphic high-electron- mobility transistors. The designed gain is 20 dB and noise figure is lower than 2 dB.

10. Design LNA Methods and Techniques
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.

11. Challenges and Solution
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

12. Design Results Noise figure and stability
It only has lower than 2 dB noise figure.
And the circuit is stable

13. Design Results-Final Layout
This two stage LNA is expected to produce the required gain

14. Roles and Responsibilities (con’t)
Peter: GHz Dielectric Resonator Oscillator (DRO)
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
OSCILLATOR
RF = 12.5 GHz
IF = 1.25 GHz
LO = Local Oscillator
IF = Intermediate Frequency
RF = Radio Frequency
LO = GHz
LO = GHz

15. Advantages of topology
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.
Advantages of topology
Very high unloaded Q (Several thousand)
lumped elements are limited to few hundred
Low phase noise (Better)
Good output power
Excellent temperature stability of material they are made from
Matching Network
Series Feedback DRO

16. Circuit Implementation In ADS
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

17. Challenges and Solutions
Getting oscillator to oscillate
Adding current pulse
Achieving desired oscillation frequency
Investigating what circuit components affect oscillator frequency.
Trial and Error. Changing LC values and re- simulating until oscillation frequency was achieved.

18. Results

19. Roles and Responsibilities (con’t)
Sarah: Active BJT Mixer
Methods and Techniques
BFU710 by NXP selected as active mixer component
Chosen mixer topology

20. Roles and Responsibilities (con’t)
Challenges and Solutions
I-V curve for BJT showing approximate bias point
Mixer starting point

21. Roles and Responsibilities (con’t)
Results and Discussion
Approximate
layout
Output Spectrum:
Output voltage at 1.25 GHz

22. Progress to Date Chosen and purchased active components
Design using ADS and HFSS
Simulation of design
Design layouts completed
Send out layouts for manufacturing

23. Next Steps Complete and test individual printed circuits
Complete second iteration of design and manufacture if necessary
Present final result in written report

24. DBS Receiver
Please stop by our poster for further technical details.

25. References
-bell-tv-subscriber-spends-75-a-month/
ite_TV_Frequency_Bands.asp
98a6.pdf
BLKG.html