1. Satellite Digital Audio Radio Service Receiver Front-End (SDARS)
Albert Kulicz
Greg Landgren
Advisor: Dr. Prasad Shastry

2. SDARS What is SDARS Overall System Block Diagram Patch Antenna
Low Noise Amplifiers (LNA)
Equipment and Parts List
Tasks for Next Semester

3. What is SDARS?
The Satellite Digital Audio Radio Service is primarily for entertainment broadcasting from orbital satellites and received by modules commonly found on modern automobiles. (ex: XM or Sirius Radio)
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 and LNA physical board design
Compared to past SDARS projects, our design will contain the entire active antenna on a single “board” consisting of two substrates as seen below.

6. Patch Antenna Passive portion of the active antenna
Receives incoming signal from satellite
Design Goal – Make it smaller than previous SDARS attempts and stay within the specified requirements

7. Antenna Requirements
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

8. Antenna Requirements Cont…
Desired: VSWR <2 or S11<-10 dB , fo = GHz , 12.5MHz BW

9. Antenna Impedance Bandwidth
.012
%BW = BW/fo = (12.5M Hz/2.326 GHz) * 100% = %

10. Antenna High Frequency Substrate - Rogers RO3003

11. 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 cm
[1] Balanis, Constantine A, “Microstrip Antennas,” in Antenna Theory, 3rd ed. John Wiley and Sons, Inc., 2005, pp

12. LHCP Probe Feed on Patch Antenna
LHCP and Probe Feed
SDARS signal from satellite is LHCP so the antenna must also be LHCP to receive the signal
LHCP Probe Feed on Patch Antenna
Using CPPATCH program we determined the distance from the center to edge (along diagonal) to be cm

13. Low Noise Amplifers (LNA)
The LNA network will take the low-power satellite signal and amplify it to a level where the Sirius receiver can reliably decode the radio channels
A cascaded network of LNAs will allow us to achieve both a low total noise factor and a high total gain
Two stages of amplification will suffice

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

15. Hittite LNAs Total Noise Factor = 0.77 Total Gain = 45 dB
Second stage Higher Gain
First stage NF <.9dB
Total Noise Factor = 0.77
Total Gain = 45 dB

16. Parts and Equipment RO3003 substrate
Sirius Radio Receiver
LNA substrate - tbd
HMC548LP3 LNA
HMC667LP2 LNA
MCL15542 DC Blocking Capacitor
EM Simulation Software (Sonnet / Momentum)
PCAAD
Agilent ADS
CPPATCH
Network Analyzer
Spectrum Analyzer
Frequency Generator
Power Supplies

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

18. QUESTIONS
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