Summer Tasks on UAV Radar

Summer Tasks on UAV Radar

Under supervision of:Shannon RodríguezLihua LiGerry Heymsfield

Manuel A. Vega-CartagenaUPRM Graduate Student

Goddard Space Flight Center

http://www.nasa.gov/

Manuel A. Vega-Cartagena2

Objective

NASA IDEAS-ER grant received.

Develop a background on radar design while contributing to the UAV project.



UAV Radar Project

The planned radar will have capabilities of ER-2 Doppler Radar (EDOP).

Nadir beam for vertical winds and precipitation structure.

Conical beam for ocean surface winds and surveillance of the precipitation regions of the storm.


Tasks

Study radar literature.

Redesign UAV’s nadir sub-system RF front end block diagram.

Help bench test UAV’s conical sub-system Tx and Rx paths.

Design 80MHz/5MHz clock PCB.

Design a PCB for UAV’s Vicor power modules.



UAV’s RF Front End Block Diagram

Requirements

– Magnetron frequency = 9.345 GHz

– Intermediate frequency = 60 MHz

– Calibration noise injection loop

– Receiver noise figure calculations



UAV’s RF Front End Block Diagram



80MHz / 5MHz PCB

Requirements

– Single 10MHz sine wave input.

– 80MHz and 5MHz TTL clock outputs for DAQ card.

– Four amplified analog sensing lines.

– Low profile components.

– PMC daughter card format.

– Original circuit design done by Shannon Rodríguez.



80MHz / 5MHz PCB

5V

-5V

Frequency MultiplierAV9170

10 MHz10 MHz 40 MHz

Clock Block Diagram:



80MHz / 5MHz PCB

PCB Construction– Board schematic and layout

done with Orcad software.– Built using router in building 22.

MezzanineConnectors

SOICComponents

D-Sub 15Sense Lines



80MHz / 5MHz PCB

Board Testing– CPCISYS carrier board with daughter card.– Only DC Power from carrier board used.– Still undergoing debugging process.



80MHz / 5MHz PCB

Test Results– 80MHz Clock Signal

80MHz TTL Clock Signal

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

-1.50E-07 -1.00E-07 -5.00E-08 0.00E+00 5.00E-08 1.00E-07 1.50E-07

Time (s)

Volta

ge (V

)

~1.3V

~0.4V



80MHz / 5MHz PCB

5MHZ Clock Signal SMA5MHz TTL Clock Signal

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

-5.00E-07 -4.00E-07 -3.00E-07 -2.00E-07 -1.00E-07 0.00E+00 1.00E-07 2.00E-07 3.00E-07 4.00E-07 5.00E-07

Time (s)

Volta

ge (V

)

~1.6V

~0.1V



80MHz / 5MHz PCB

Sensing Lines– Two additional lines were added.– Two inverting amplifier stages.– Gain values were changed.

3

21

411

-

+

U1A

LM324/SO

5

67

411

-

+

U2B

LM324/SO

0 0

R1

R

R2

R

R3

R

R4

R

VinVout



80MHz / 5MHz PCB

Sense Lines– Tested using 10Vpp 1kHz

sine wave.

– Theoretical voltage gain value = 2.25.

– Gain variations may be caused by tolerance in resistances.

Sense LineOutput Voltage (Vpp)

Voltage Gain

1 19.53 1.953

2 20.31 2.031

3 19.53 1.953

4 19.53 1.953



Vicor Power Modules PCB

Requirements– Eliminate wire connections

between modules.

– Reduce mounting time.

– Only one board for both +/- voltage configurations.

– Output voltages should be accessible and easy to change(+/- 5V, +/-12V, +/-15V).




Design Schematic– Power modules PCB.

Voltage selection jumper and output.

Wire connections elimination.

Bypass capacitors.

Chassis ground connection. 12

J1+28V

12

J2

GND

IN-

Gate

OUT

Gate

IN

IN+

OUT-

OUT+

-S

Trim +S

U1Vicor DC-DC Converter

-IN1

-Sin

2

+Sin

3

+IN

4

-OUT

9

-Sou

t8

NC7

+Sou

t6

+OUT

5

U2VI-RAM-I2

0

To Plate Screw

From Power Distribution Matrix

To Power Distribution Matrix

C1CAP

C2CAP

C3CAP

C4CAP

00

0 0

1 2 3 4

J3+/- OUT

0



PCB Construction– Maximum load currents calculation.

Imax = 5 A @+24VIN for 5V module. 12V and 15V modules have lower output currents. Track widths for 10°C temperature increase = 110 mils. Track clearances for +28V = 29 mils. Entire design done using standard low-cost 1oz. Cu thickness

board.– Components selection.

Connectors with unexposed contacts.



Finished Board

+28V Input

Chassis Ground

Output and VoltageSelection Jumper



Power Distribution Matrix– Used to eliminate barrier

block.– Makes output voltages more

accessible and easy to change.

12

J4+5V

12

J5-5V

12

J6+12V

12

J7-12V

1 2

J8+28V

1 2

J9+28V

1 2

J10+28V

1 2

J11+28V

1 2

J12+28V

To Power Modules

From AircraftFrom Power Modules

0

0

NOTE: All voltages available at each connector.Total Components = 10

To Components

12

34

56

J13CON6A

12

34

56

J14CON6A

12

34

56

J15CON6A

12

34

56

J16CON6A

12

34

56

J17CON6A

From Aircraft

To Power ModulesTo Components

From Power Modules



Finished BoardFrom Aircraft

To Power ModulesFrom PowerModules

To Components



Final Configuration


UAV’s Conical Sub-System Tx and Rx Paths Testing

Task performed to gain hands-on experience.


Learning Experience

Radar Theory Background– RF Front End Design– Power Requirements

PCB Design– ORCAD– Routing machine

Design Implementation


Conclusions

Goals achieved!– 80MHz/5MHz daughter card PCB developed– Power Modules PCB design developed

Gained valuable hands-on experience.


Questions


List of Acronyms

UAV – Unmanned Air Vehicle IDEAS – Initiative to Develop Education through Astronomy

and Space Science DCAS – Distributed Collaborative Adaptive Sensing PCB – Printed Circuit Board TTL – Transistor-Transistor Logic


Acknowledgements

Shannon Rodríguez / 555 Lihua Li / 912 Gerry Heymsfield / 613 Wai Fong / 567 Gerry McIntire / 613

Summer Tasks on UAV Radar

Documents

vegacartagenauavs rf

radar design

design 80mhz5mhz clock

subsystem rf

end block diagrammanuel

doppler radar edop

conical beam

daughter card format