Satellite Digital Satellite Digital Audio Radio Audio Radio

ServiceServiceReceiver Front-EndReceiver Front-End

(SDARS)(SDARS)Albert KuliczAlbert Kulicz

Greg LandgrenGreg Landgren

Advisor: Dr. Prasad ShastryAdvisor: Dr. Prasad Shastry

SDARSSDARS

What is SDARSWhat is SDARS Overall System Block DiagramOverall System Block Diagram Patch AntennaPatch Antenna LLow ow NNoise oise AAmplifiers (LNA)mplifiers (LNA) Equipment and Parts List Equipment and Parts List Tasks for Next Semester Tasks for Next Semester

What is SDARS?What is SDARS?

The The SSatellite atellite DDigital igital AAudio udio RRadio adio SService is ervice is primarily for entertainment broadcasting from primarily for entertainment broadcasting from orbital satellites and received by modules orbital satellites and received by modules commonly found on modern automobiles. (ex: commonly found on modern automobiles. (ex: XM or Sirius Radio)XM or Sirius Radio)

This project involves designs, simulations, This project involves designs, simulations, fabrication, and testing of a patch antenna and fabrication, and testing of a patch antenna and low-noise amplifier (LNA) to receive SDARS low-noise amplifier (LNA) to receive SDARS signals by means of SIRIUS receiver. signals by means of SIRIUS receiver.

The inclusion of the entire active antenna The inclusion of the entire active antenna (passive antenna + impedance matching network (passive antenna + impedance matching network + LNA) will be designed to minimize physical + LNA) will be designed to minimize physical size, while producing the best quality of signal.size, while producing the best quality of signal.

System Block DiagramSystem Block Diagram

Passive Antenna

Low Noise Cascaded Amplifier Network

Impedance Matching Network

Active Antenna on PCB

F1 F2

G1 G2

SIRIUS Radio Receiver

Incoming Circularly Polarized Satellite Signal (-105 to -95)dbm

Antenna and LNA physical Antenna and LNA physical board design board design

Compared to past SDARS projects, Compared to past SDARS projects, our design will contain the entire our design will contain the entire active antenna on a single “board” active antenna on a single “board” consisting of two substrates as seen consisting of two substrates as seen below. below.

Patch AntennaPatch Antenna

Passive portion of the active antenna Passive portion of the active antenna Receives incoming signal from Receives incoming signal from

satellitesatellite Design Goal – Make it smaller than Design Goal – Make it smaller than

previous SDARS attempts and stay previous SDARS attempts and stay within the specified requirements within the specified requirements

Antenna RequirementsAntenna Requirements

Receive signals in the frequency band Receive signals in the frequency band from 2.32 GHz to 2.3325 GHz (BW of from 2.32 GHz to 2.3325 GHz (BW of 12.5 MHz)12.5 MHz)

LLeft eft HHand and CCircular ircular PPolarization olarization (LHCP)(LHCP)

Match in impedance to LNA network Match in impedance to LNA network

(~50 Ohms)(~50 Ohms)

Probe Feed – Placement will determine Probe Feed – Placement will determine polarization and impedance match polarization and impedance match

Antenna Requirements Antenna Requirements Cont…Cont…

Desired: VSWR <2 or S11<-10 dB , fo = 2.326 GHz , 12.5MHz BW

Antenna Impedance Antenna Impedance BandwidthBandwidth

.012

%BW = BW/fo = (12.5M Hz/2.326 GHz) * 100% = 0.537%

Antenna High Frequency Antenna High Frequency Substrate - Rogers Substrate - Rogers

RO3003RO3003

Antenna Dimension Antenna Dimension EquationsEquations

(L=W for square patch)(L=W for square patch) Initial length L = c/(2fo* Initial length L = c/(2fo* εεr^(1/2))r^(1/2))

εεeff= (eff= (εεr+1)/2 + (r+1)/2 + (εεr-1)/2*[1+12(h/L))^(-r-1)/2*[1+12(h/L))^(-1/2)1/2)

Fringe factor, Fringe factor, ΔΔL=0.412 h (ε eff + 0.3)L=0.412 h (ε eff + 0.3)( W/h + 0.264) / ( (ε eff - 0.258)(W/h + ( W/h + 0.264) / ( (ε eff - 0.258)(W/h + 0.8))0.8))

New length L = c/(2fo* New length L = c/(2fo* εεeff^(1/2)) - 2eff^(1/2)) - 2ΔΔLL repeat iterative process repeat iterative process 3.692cm x 3.692 cm 3.692cm x 3.692 cm

[1] Balanis, Constantine A, “Microstrip Antennas,” in Antenna Theory, 3rd ed. John Wiley and Sons, Inc., 2005, pp. 811-882

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 0.382 cm

Low Noise Amplifers Low Noise Amplifers (LNA)(LNA)

The LNA network will take the low-The LNA network will take the low-power satellite signal and amplify it to power satellite signal and amplify it to a level where the Sirius receiver can a level where the Sirius receiver can reliably decode the radio channels reliably decode the radio channels

A cascaded network of LNAs will allow A cascaded network of LNAs will allow us to achieve both a low total noise us to achieve both a low total noise factor and a high total gain factor and a high total gain

Two stages of amplification will suffice Two stages of amplification will suffice

LNA RequirementsLNA Requirements

Noise factor shall be <= 1dBNoise factor shall be <= 1dB

NF = FNF = F1 1 + (+ (FF2 2 -1)/G-1)/G1 1 + (F+ (F33-1)/(G-1)/(G11*G*G22 ))++ . . . . . .

Total gain shall be -> 40~50 dBTotal gain shall be -> 40~50 dBGGtotaltotal = = G G11 + G+ G2 2 + . . .+ . . .

Hittite LNAsHittite LNAs

First stage NF <.9dB Second stage Higher Gain

Total Noise Factor = 0.77 Total Gain = 45 dB

Parts and EquipmentParts and Equipment RO3003 substrateRO3003 substrate Sirius Radio Sirius Radio

Receiver Receiver LNA substrate - tbd LNA substrate - tbd HMC548LP3 LNAHMC548LP3 LNA HMC667LP2 LNAHMC667LP2 LNA MCL15542 DC MCL15542 DC

Blocking CapacitorBlocking Capacitor

EM Simulation Software (Sonnet / Momentum)

PCAAD Agilent ADS CPPATCH Network

Analyzer Spectrum

Analyzer Frequency

Generator Power Supplies

Tasks for Next SemesterTasks for Next Semester Complete EM simulations with Sonnet and Complete EM simulations with Sonnet and

Momentum and optimize antenna design (Feb)Momentum and optimize antenna design (Feb) Test LNA evaluation boards with NA (Feb)Test LNA evaluation boards with NA (Feb) Design Impedance Matching for the LNA network Design Impedance Matching for the LNA network

(Feb) (Feb) Design Bias Circuitry for the LNAs (March)Design Bias Circuitry for the LNAs (March) Simulate entire active antenna in Agilent ADS Simulate entire active antenna in Agilent ADS

(March)(March) Outsource Fabrication of Substrates (March)Outsource Fabrication of Substrates (March) Test Fabricated Antenna and LNA Substrates Test Fabricated Antenna and LNA Substrates

(April)(April) Test complete system active antenna board with Test complete system active antenna board with

Sirius Receiver (April)Sirius Receiver (April)

QUESTIONS

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