Microwave Remote Sensing Laboratory The Design and … · 2008-07-01 · Microwave Remote Sensing...

The Design and Characterization of Ku- and Ka-bandDownconverter for Spaceborne Interferometric Radar

Microwave Remote Sensing Laboratory

2008 ESTC

Paul Siqueira , Harish Vedantham, Edin Insanic, Razi Ahmed (Umass)

Michael Tope, Gerry Walsh (JPL)

The Design and Characterization of aKu- and Ka-band Downcoverter for Spaceborne

Interferometric Radar

Microwave RemoteSensing Laboratory

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2008 ESTC

Approach

o Ku-band system

• Construct breadboard model to understand basiccharacteristics

• Build on breadboard experience to create flight prototypemodel

• Perform functional tests (noise figure, gain, etc.) onprototype model

• Performance tests on prototype model (phase andamplitude stability over temperature)

• Use prototype model in a working interferometric system

o Repeat above for Ka-band system


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2008 ESTC

Design Specifications

> 30 dB> 30 dBImage Rejection

65 to 70 dB65 to 70 dBDDC End to End Gain

-100 to –65 dBm-100 to –65 dBmInput Signal Range

0.3 dB RMS over BW0.3 dB RMS over BWReceiver Amplitude Variation over Best Linear Fit

2 dB over BW2 dB over BWReceiver Amplitude Variation

3 deg RMS over BW3 deg RMS over BWReceiver Phase Variation over Best Quadratic Fit

0.050 degrees RMS over BW0.050 degrees RMS over BWRelative Channel to Channel Phase Stability

< 1.5:1< 1.5:1Input/Output VSWR

> 80 dB> 80 dBChannel to Channel Isolation

5-25 MHz5-25 MHzOutput Frequency Range

< 4.5 dB< 4.5 dBNoise Figure

-10 to 50 degrees-10 to 50 degrees COperating Temperature

34975 – 34995 MHz13275 – 13295 MHzInput Frequency Range

< 30 MHz< 30 MhzEffective Noise Bandwidth

20 MHz20 MHzSignal Bandwidth

Ka-band DDCKu-band DDCDesign Constraint


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2008 ESTC

Cross-Track InterferometryE 1

Im{E}

Re{E}

H

E 1

B

E 2

look

ang

le

ambi

guit

y

z

E 2

E 1E2*

Im{E}

Re{E}

rangeto target

z = H cos sin1

a2 B

= sin1

a2 B


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2008 ESTC 5

Phase Measurement Accuracy

AH, altitudeA , target range

A , baseline tilt

A , wavelengthstability

A , phase noise

AB, baselinelength

z

2

=dz

d

2

2

+dz

dB

2

B

2

+dz

d

2

2

+dz

dH

2

H

2

+dz

d

2

2

+dz

d

2

2

SRTM,

C-band 60m

WSOA, Ku-band 6.4m


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2008 ESTC 6

Introduction

o OSTM:WSOA (ocean

surface topographymission: wide swathocean altimeter)

o GRACE (gravity

recovery and climateexperiment)


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2008 ESTC

SWOT/KaRIN

Surface Water and Ocean Topography Mission

Decadal Survey, 2013-2016

200 MHz Bandwidth

Technology Follow-on to WSOA

River discharge estimates; Lake, wetland and reservoir

storage; ocean eddies and currents


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2008 ESTC

Block Diagram of an Interferometric System

control, timing

and waveform

generation

RF

upconversion

and power

amplification

processing and

data storage

Antenna subsystem

transmit

receive

receiveT/R

switch

RF Electronics

spac

ecra

ft b

us

Low frequency electronics

DDC

RF

down-

conversion

ESTO ACT

Project

Ku-band

Ku-band



2008 ESTC

Ku-bandDownconverterDevelopment


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2008 ESTC

DDC Version 1


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2008 ESTC

Alternate Clamshell Layout


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2008 ESTC

Critical Signal Path

Ku-band Section

L-band Section


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2008 ESTC

DC power and low frequency electronics



2008 ESTC

Ku-Band Downconverter

design layout

actual device

test ports

RF

In

IF o

ut

temperature, power

and current telemetry

A careful system design approach was used to

meet strict performance requirements and to

monitor the downconverter under various

operating environments

A new, final enclosure, is currently

being designed to improve isolation

Space qualifiable design principles and

practices used throughout the

development process


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2008 ESTC

Single Surface, multilayer (4) layout



2008 ESTC

Ku-band DDC Silkscreen Layout

4.5”

7.5”2.5”

4.5”

L-band & UHFKu-band


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2008 ESTC

Ku-band Respin to improve isolation

On-board cavities used to isolate filters


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2008 ESTC

New Ku-band DDC Housing

Additional cavity walls carved into housing to improve isolation


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2008 ESTC

Final Ku-band board



2008 ESTC

Ka-BandDownconverterDevelopment


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2008 ESTC

Silkscreen for Ka-band to UHF DDC7”3”

5”

L-band & UHFKa-band


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2008 ESTC 22

In-line LO filter (small footprint)


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2008 ESTC 23

Orthogonal LO filter (large footprint, better isolation?)


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2008 ESTC

Addressing Isolation


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2008 ESTC

The final product


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2008 ESTC

Top Layer of Ka- to L-band downconverter



2008 ESTC

Testing


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2008 ESTC

Basic Performance: Downconversion of 14 GHz tone

Baseband Baseband & IF


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2008 ESTC

Two Channel Amplitude Performance

• < 1 dB between the two channels over frequency.

• < 1.5 dB variation over BW (2 dB reqm't)

• Better than 0.15 dB from linear fit over the passband (0.3 dB reqm't)

channel 1

channel 2

best linear fit



2008 ESTC

First Evaluation Results

Two-Channel Gain Balance=1.5dB

Nominal Gain = 70 dB

P1dB=19dBm

Noise figure=3.5dB

Input Return Loss ~ 11 dB

Two-channel isoloation = 66 dB

Inter-channel phase difference stability (Standard

Deviation) = 0.213°

Phase standard deviation from best quadratic

fit = 0.04° (0.05 ° rqmt.)

Supply = 14.5 V,

830 mA

Power = 12W


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2008 ESTC

Test Setup Schematic

STALO

amp1

1

amp2

2

= 2 -

1

Signal

injection

• AWG

• Caltone

• Chirp

Thermally

Stabilized

Environment

Thermally Controlled

Environment A/D conversion

performed with digitial

oscilloscope

processing

characterization

controller

measurementoutput statistics

DUT


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2008 ESTC


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2008 ESTC

Phase Difference, Temperature, and Best Fit Model



2008 ESTC

Thermal TestingThermally isolating the downconverter (breadboard

model) leads to a 20 mdeg phase error over time.


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2008 ESTC

Controlled Thermal Testing0.25oC/second, 15oC/min; -100oC to 300oC temperature range

Remote operation via serial port or IEEE-488 bus


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2008 ESTC

Early thermal test results (-10 to 45 deg C) -- Ku-band


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2008 ESTC

More Thermal Cycle Experiments -- Ku-band


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2008 ESTC

Reaching Thermal Stability (Ka-band)


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2008 ESTC

Temperature and Phase Fluctuations in an unprotected environment

Ka-band


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2008 ESTC

Temperature and Phase Fluctuations in a Protected Environment

Ka-band


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2008 ESTC

Ku-band Performance Numbers

> 30 dB, but still being tested> 30 dBImage Rejection

61.2 dB65 to 70 dBDDC End to End Gain



<1.5 dB over BW2 dB over BWReceiver Amplitude Variation

still being tested3 deg RMS over BWReceiver Phase Variation over Best Quadratic Fit

0.040 degrees RMS0.050 degrees RMS over BWRelative Channel to Channel Phase Stability

1.14:1 (worst case)< 1.5:1Input/Output VSWR

~ 70 dB> 80 dBChannel to Channel Isolation

5-25 MHz (nominal)5-25 MHzOutput Frequency Range

< 3 dB< 4.5 dBNoise Figure

still being tested-10 to 50 degrees COperating Temperature

33275 – 13295 MHz (nominal)13275 – 13295 MHzInput Frequency Range

20.3 MHz (adjustable)< 30 MhzEffective Noise Bandwidth

20 MHz (adjustable)20 MHzSignal Bandwidth

Ku-band DDC actualKu-band DDC plannedDesign Constraint


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2008 ESTC

Ka-band Performance Numbers

still being tested> 30 dBImage Rejection

70 dB65 to 70 dBDDC End to End Gain



<1.5 dB over BW2 dB over BWReceiver Amplitude Variation

still being tested3 deg RMS over BWReceiver Phase Variation over Best Quadratic Fit

0.040 degrees RMS0.050 degrees RMS over BWRelative Channel to Channel Phase Stability

1.5:1< 1.5:1Input/Output VSWR

~ 66 dB> 80 dBChannel to Channel Isolation

5-25 MHz (nominal)5-25 MHzOutput Frequency Range

< 3.5 dB< 4.5 dBNoise Figure

still being tested-10 to 50 degrees COperating Temperature

34975 – 34995 MHz (nominal)34975 – 34995 MHzInput Frequency Range

still being tested< 30 MhzEffective Noise Bandwidth

20 MHz (adjustable)20 MHzSignal Bandwidth

Ka-band DDC actualKa-band DDC plannedDesign Constraint


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2008 ESTC

TRL Definitions

begin

current


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2008 ESTC

Mission Scenarios• Enabling Technology: High phase accuracy and low cross-talk two-channel Ku- and Ka-band downconversion to IF.

• Generic capabilities

• precision polarimetry

• precision interferometry (along-track and cross-track)

• index of refraction studies for the atmosphere

• Airborne

• compact side-looking interferometer for topographic and volumetricdepth measurements

• Spaceborne

• detailed characterization will provide key inputs for mission designand observing scenarios

• Surface Water Ocean Topography (SWOT)

• Sea Ice, cold lands process and gravitational satellites


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2008 ESTC

TRL advancement

target area


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2008 ESTC

Slotted Waveguide Antenna Design

Baseline

separation


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2008 ESTC

Slotted Waveguide Antenna Implementation


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2008 ESTC

The Ka-band Slotted Waveguide Antenna

A near-field probe is used to test the antennaperformance


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2008 ESTC

First interferometric results at 35 GHz!Interferometric

correlation

magnitude

ej

=E1E2

*

E1

2

E2

2


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2008 ESTC

Potential for an Airborne Platform


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2008 ESTC

Academic Output

Two date, the project has generated:

• Four Masters degrees (two continuing on for a PhD, anotherworking at NASA-Marshall)

• One Journal Paper (IEEE MTT), One in progress, One book

• Four undergraduate projects

IEEE MTT, 55(10), 2007

Harish Vedantham, 2008

Razi Ahmed, 2006



2008 ESTC

End

Microwave Remote Sensing Laboratory The Design and … · 2008-07-01 · Microwave Remote Sensing...

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Transcript of Microwave Remote Sensing Laboratory The Design and … · 2008-07-01 · Microwave Remote Sensing...