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Reliable, tuneable andinexpensive antennas by

collective fabrication processes

RF-MST Cluster Meeting, June 30th, 2008 – Heraklion, Greece

V. Ziegler

EADS Innovation Works, Munich, GermanyThales Aeronautic Division, Elancourt, FranceIMEC, Leuven, BelgiumESIEE, Paris, FranceCoventor, Paris, FranceEPFL, Lausanne, SwitzerlandJSI, Ljubljana, SloveniaHYB, Sentjernej, Slovenia

EADS Innovation Works, Munich, GermanyThales Aeronautic Division, Elancourt, FranceIMEC, Leuven, BelgiumESIEE, Paris, FranceCoventor, Paris, FranceEPFL, Lausanne, SwitzerlandJSI, Ljubljana, SloveniaHYB, Sentjernej, Slovenia

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RETINA – Project data

Contract Nr.: AST4-CT-2005-516121

Total Cost: 5.189.032 €

EU Contribution: 3.170.000 €

Starting Date: 01/02/2005

Ending Date: 29/02/2008

Duration: 37 months

Website: http://dolomit.ijs.si/RETINA

Coordinator: Dr. Volker ZieglerEADS Innovation Works Germany

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- no additional drag- electrical beam-steering- bi-directional broadband

RETINA – SatCom antenna for AIRBUS

The specifications:

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Reflect-Array – Principle functionality

AIRCRAFT CABIN

MAST

T/R MODUL

REFLECTARRAY +RADOME

Radiating element

Phase shifter

Reflect

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Phase shifting topologies in RETINA

Influence the wave inside thewaveguide by a small component.

Sideview of unit cell

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Tasks to realize the demonstrator

• Develop (layout, fabricate and test) single devices in both technologies.RF-MEMS switches and tunable capacitances, ferroelectric tunable capacitances

• Assess the reliability performance of the devices

• Develop waveguide phase shifters based on the single devices

• Design and fabricate the demonstrator (DC-control unit, RF-unit)

• Characterize the RF-performance of the demonstrator

The demonstator of the RETINA project is a planar reflect array, whichis able to perform electrical beam-steering based on advanced phaseshifting technologies.

Tasks from Year 1 to Year 3

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Phase shifting devices

2 main technologies were developed in the project

Ferroelectric technology RF-MEMS technology

Ferroelectrictunable capacitor

RF-MEMStunable capacitor

RF-MEMSswitch

Tunabilityup to 3.5

Insertion losses < -0.2dB

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Waveguide phase shifters

Waveguide phase shifters were designed, fabricated and measured

Ferroelectric tunable capRF-MEMS tunable cap.

RF-MEMS switches

Design:

Realized andmeasuredphase shifters:

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Waveguide phase shifters – Achievements after Year 2

Key technical requirements for the phase shifters in the demonstrator:• Cover the whole frequency range from 10.95 – 12.75GHz• Exhibit low losses• Perform the required phase shift (3Bit) over the bandwidth

Bandwidth: o.kLosses: acceptablePhase shift: lowTechnology: more complex

Bandwidth: lowLosses: decentPhase shift: acceptableTechnology: simple

Ferro RF-MEMS

Go for demonstratorwith improved bandwidth

Reduce size and improvepackaging for higher phase shift

Achie

ved

perfo

rman

ce

afte

r year

2

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Technology optimisation example: RF-MEMS capacitors

Good RF-performances achieved :tunability up to 3,5 ---- IL~2dB ---- electrical resonance frequency >18GHz

1. Tunability between 3 to 3.5 with small Capacitor values (~100fF)

2. Pull-in voltage Vp <25V3. Low mechanical stress4. Sort of on-wafer packaging5. Reduced chip size (2,5x2mm2 packaged with interconnect pads)

• dual-gap process (Silicon/glass technology)• metal thickness optimization to reduce stress

3rd year

Results after Year 3:

2.5 x 3mm 2 x 2.5mm

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Technology optimisation example: RF-MEMS switches:

Excellent RF-performance achieved (IL = -0.19dB, IS = 18.0dB) by:

1. Enhanced lifetime (109 switching cycles)2. High temperature of operation (120°C for 48h)3. RF-power handling ( >6W hot-switching)4. on-wafer low dielectric packaging5. reduced chip size (1.0x0.8mm2 packaged with interconnect pads)

• changing metal composition• metal thickness• substrate thickness

3rd year

Results after Year 3:

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Reliability tests – examples from Year 3

RF-MEMS switch operationat elevated temperatures

Ferroelectric capacitance lifetimeactuation cycles

RF-MEMS switch power handlingunder hot-switching conditions

• RF-MEMS switches were testedextensively during years 1 and 2.

• Year 3 was focussed on ferroelectrics.

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Development: Software tool „Design for reliability“ for RF-MEMS

Material and Process Characterization

Test structure Design, Modeling,Experimental Data Extraction

System-Level Design

Stable statebefore drop

drop

shockacceleration

time

Shock-test, switching cycle, IC/package-co-design, non-linearities etc.

Mask Layout Virtual Prototyping

SEM image SEMulator3D image

Failure analysis, process defects,mask misalignment etc.

FEM/BEM Analysis

Mechanical Stress, chargedistributions, temperature cycles etc.

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RETINA Demonstrator – Partial reflect array antenna

SatCom antenna mock-up with demonstrator

Linear reflect array with 24 waveguide phase shifters

Demonstrator layout

Electr. beam steering

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Conclusions

• Different waveguide phase shifters were fabricated and testedusing the components under evaluation:- Tunable RF-MEMS capacitors- RF-MEMS switches- Ferroelectric thin film tunable capacitors

• A simulation tool “Design for Reliability” for RF-MEMSwas developed (incl. Shock analysis)

• Extensive reliability testing and technology optimization lead toremarkable improvement of the device performances after Year 3

• Demonstrator was designed, fabricated and successfully measured

• 42 papers and publications were made

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Acknowledgement for a very successful project

The project “RETINA” was supported bythe European Commission under theFramework Program 6.2003 AERO1 #516121

Contact: volker.ziegler@eads.net