1. SDARS Receiver Front-End (Design Review)
Albert Kulicz
Greg Landgren
Advisor: Prasad Shastry

2. Outline Overview Goals Tasks for Semester Antenna LNA Network
Fabrication
Tentative Schedule

3. What is SDARS?
This project involves designs, simulations, fabrication, and testing of a patch antenna and low-noise amplifier (LNA) to receive SDARS signals by means of SIRIUS receiver.
The inclusion of the entire active antenna (passive antenna + impedance matching network + LNA) will be designed to minimize physical size, while producing the best quality of signal.

4. System Block Diagram
Incoming Circularly Polarized Satellite Signal (-105 to -95)dbm

5. Antenna Goals
Receive signals in the frequency band from 2.32 GHz to GHz (BW of 12.5 MHz)
Left Hand Circular Polarization (LHCP)
Match in impedance to LNA network
(~50 Ohms)
Probe Feed – Placement will determine polarization and impedance match

6. LNA Goals Noise factor shall be <= 1dB
NF = F1 + (F2 -1)/G1 + (F3-1)/(G1*G2 )
Total gain shall be -> 40~50 dB
Gtotal = G1 + G

7. Tasks for Semester
Complete EM simulations with Momentum and optimize antenna design (Feb)
Test LNA evaluation boards with NA (Feb)
Design Impedance Matching for the LNA network (Feb)
Simulate entire active antenna in Agilent ADS (March)
Design Bias Circuitry for the LNAs (March)
Outsource Fabrication of Substrates (April)
Test Fabricated Antenna and LNA substrates (May)
Test complete systems active antenna board with Sirius Receiver (May)

8. 3D Passive Antenna Model

9. Antenna Dimension Equations
(L=W for square patch)
Initial length L = c/(2fo* εr^(1/2))
εeff= (εr+1)/2 + (εr-1)/2*[1+12(h/L))^(-1/2)
Fringe factor, ΔL=0.412 h (ε eff + 0.3)( W/h ) / ( (ε eff )(W/h + 0.8))
New length L = c/(2fo* εeff^(1/2)) - 2ΔL
repeat iterative process cm x 3.69 cm
[1] Balanis, Constantine A, “Microstrip Antennas,” in Antenna Theory, 3rd ed. John Wiley and Sons, Inc., 2005, pp

10. PCAAD (design for 2.326ghz)

11. EM Simulation / Optimization
Agilent ADS - Patch Antenna S11

12. Patch Antenna – Top View
Probe location: [x] cm x [y] cm (0.509 cm from center)

13. EM Simulation / Optimization
Agilent ADS - Patch Antenna S11
Impedance = Zo*(0.978-j0.001)

14. Antenna – Dissected Side View
Probe Feed:
copper wire diameter – 0.15 cm
Probe hole – cm

15. Antenna - Bottom View (LNA network)

16. LNA schematics

17. Powered by Sirius Receiver
LNA experimental Gain
Powered by Sirius Receiver

18. Entire System (Passive Antenna & LNA)
S11 (return loss)
Entire System (Passive Antenna & LNA)

19. Fabrication Microcircuits, Inc. CAMtek, Inc.
Using Gerber files for both antenna and LNA layouts
CAMtek, Inc.
Soldering
Room for error, so we will have to gather 2 antennas from Microcircuits (just in case).

20. Tentative Schedule
Finalize Antenna and LNA layout and send Gerber file to Microcircuits (Mar.9)
Test fabricated Antenna performance (March)
Send fabricated LNA substrate to CAMtek for soldering (March)
Assembly of completed boards, solder probe, mount to a Plexiglas or plastic encasing (April)

21. Conclusion Finalized patch antenna dimensions and probe location
LNA network gain will not meet proposed goal, but will suffice for our purposes
Simulations show respectable return loss at desired bandwidth
Fabrication and Assembly to be completed

22. References Report.” Bradley University, Spring, 2001.
[1] Zomchek, Greg and Zeliasz, Erik. “SDARS Front-End Receiver: Senior Capstone Project
Report.” Bradley University, Spring, 2001.
[2] Lockwood, Kevin. “SDARS Front-End Receiver: Senior Capstone Project Report.”
Bradley University, Spring, 2011.
[3] Balanis, Constantine A., “Microstrip Antennas,” in Antenna Theory, 3rd ed. John Wiley
and Sons, Inc., 2005, pp
[4] Pozar, David M. and Schaubert, Daniel H. “A Review of Bandwidth Enhancement
Techniques for Microstrip Antennas,” in Microstrip Antennas: the analysis and design of
microstrip antennas and arrays Institute of Electrical and Electronics Engineers, Inc., 1995, pp