adv in mems for rf tech anim
TRANSCRIPT
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8/8/2019 Adv in MEMs for RF Tech Anim
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Special Projects Office
ADV in MEMS RF SYS 100600
DARPADARPA
Advances in MEMs for RF Technology
2000 AOC Radar and EW ConferenceSession 2:Technology Developments
& Impact on Radar/ESM
25 October 2000
Mr. Vince Sieracki
Naval Air Systems Command
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ADV in MEMS RF SYS 100600
DARPADARPAMEMS
(Micro ElectroMechanical Systems)
Outgrowth of Micromachining
Creation of unique physical structures through the use of sacrificiallayers resulted in miniature mechanical structures on a substrate (often
Silicon)
Open Circuit / Low Capacitance
Dielectric Layer
Closed Circuit / High Capacitance
MEM Switch in RF Applications
Acts as RF Switch Or Capacitor (100:1 ratios)
Loss dominated by conductor loss
Controlled By Static DC Voltage (10 nJ switching energy)
Low cost processing (~ 5 mask layers)
High Cutoff Frequency Minimum intermodulation distortion
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DARPADARPARF MEMS Switch Classification(1.)
Signal Path: Capacitive; Contact Structure: Cantilever; Bridge; Membrane; Lever Arm; Rotary; Free FloatingActuation: Electrostatic; Electromagnetic; Thermal Topology: Series; Shunt; Combined
Pull-Back: Spring; Active Throw: Single; Multiple
Copper (17 um)
Polyimide (25 um) Thin dielectric (~ 1 um)
Substrate
Ball Aerospace - polymer MEMS switch
(3/29/00 Design Review)
Antenna array on
Duroid
600 um
100 um
200 um
Univ. of Colorado - polymer MEMS switch
(3/28/00 Design Review)
Raytheon bow-tie
MEMS switch
(2/1/00 Design Review)
Univ. of Illinois - floating beam switch
(4/11/00 Design Review)
HRL - contact switch
(1/31/00 Design Review)
GTRI - contact switch
(Jan 00 Progress Report)
RF
Contact
Apply
Voltage to
Clamp
CantileverArm
Magnet
Na2SO4Hg
1V-3V
RF out
RF in
UCLA - liquid metal switch
(3/30/00 Design Review)Univ. of Michigan (Rebeiz)
- microbridge switch
(5/10/00 Design Review)
1.RF MEMS Switches, R. Strawser et.al., Air Force Research Lab, Sept 12, 2000
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ADV in MEMS RF SYS 100600
DARPADARPA
MEMS SwitchCapacitively Coupled
Deposit and pattern bottom metal
Deposit and pattern dielectric
Deposit and pattern sacrificial layer
Deposit, pattern, and release top metal
Typical Fabrication Process
Deposit and pattern bottom metal
Actuation electrode RF line
Deposit and pattern sacrificial layer
Deposit and pattern dielectric
Form contact dimple
Deposit and pattern top metal and top dielectric
Release switch
MEMS SwitchMetal Contact
1
1 Schematics are from the Air Force Research Laboratory/ Aerospace Components Division
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ADV in MEMS RF SYS 100600
DARPADARPA
Properties1Switch TypeInsertion
Loss
Isolation Power
Consumption
DC
Voltage
Speed Bandwidth
PIN/SCHOTTKY ~.15 dB 45 dB 1-5 mW
per device
1-10 V 1-5 ns Narrow/
Wide
GaAs FETs 1-2 dB ~20 dB 1-5 mW
per device
1-10 V 2-10 ns Narrow/Wide
HBT/PIN 0.82 dB 25 dB 1-5 mW
per device
1-10 V 1-5 ns Narrow/
WideBest FET 0.5 dB 70 dB 5 mW 3.5 V 2 ns Narrow/
WideMEMS SergioShunt
0.06 dB @
20 GHz
30 dB ~1W 12-14 V > 30s Wide(1-40 GHz)
MEMS Scott/Jeremy(Shunt)
0.3 dB @30 GHz
50-60 dB ~1W ~20 V > 30s Moderate(10-40 GHz)
Why RF MEMS?
1 Sanders RECAP In-Process Review 2/00
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ADV in MEMS RF SYS 100600
DARPADARPA
Reconfigurable Apertures
Elements
Ground planes
Array feeds/architecture Phase shifters
Filters
MEMS RF Applications
Advantages of RF MEMS
High performance, low biaspower consumption
Potential low costmanufacturing into a varietyof substrates
Limitations of RF MEMS
Slower switching speed
Potential lifetime limitations
DARPA/SPO is attempting to exploit these MEMS device/componentcapabilities in RF SYSTEMS through the following programs:
RECAP; MEM-Tenna; Global Eye-STAR.
APP
LICATIONS
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ADV in MEMS RF SYS 100600
DARPADARPA
Overall Goals
Tailoring a radiation pattern dynamically
- Greater than a Decade bandwidth coverage ;Geometric reconfiguration (horizon-to-horizon)
- Adapt to frequency spectrum changes
Reconfigurable Aperture Program
RECAP
Reconfiguration For Optimized Performance
Employ Variable radiatingtopology
Create a frequency independent
multi layer ground plane
Active Reconfigurationof Elements
Composite StructuralPackaging
Wide Band FeedNetwork
Basic Antenna
Ground plane
Wire Radiator Element
Feed
~/4
Basic Antenna
Ground planeGround plane
Wire Radiator Element
Feed
~
RF MEMS currently under investigation as a reconfiguration mechanism
in each of these areas.
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DARPADARPA
Control Chip
Micro-switch
Metallic Pad
GTRI Concept is the Adaptive Design of Element
From the Connections Between Conducting Pads
(Pads are Not Patch Antennas, But Simple Conducting Structures
Connected Pads
Forming
a Bow-tie Pattern
Feed
MEMS in a Variable Radiating Topology1
1
GTRI DARPA RECAP Symposium 2000 - 8
RECAP Element Anticipated Capability: Allows Adaptive Optimization for Frequency Band Allows Steering of Pattern for Single Feed Aperture
Lets User Adaptively Trade Bandwidth for Gain
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ADV in MEMS RF SYS 100600
DARPADARPA Example of a Reconfigurable Antenna Element
Switches Open
Switches Closed
11 GHz 18 GHz
1
2
1
2
1
2
MICROSTRIPLINE FEED
DIEL
ECTR
IC2
GROUNDPLANE
APERTURE
MEM SWITCHDIPOLE
DIEL
ECTR
IC1
MEMS-SWITCHED DUAL-BAND
DIPOLE ANTENNA1
1 RECAP Quarterly Review 3/30/2000
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ADV in MEMS RF SYS 100600
DARPADARPA
Predicted Boresight Gain Relative to Free Space(No Resistive Bias Film)
MEMS in a Wideband Ground Plane
2-18 GHz frequency range
~0.5 inches
FSS
MEMS
Reconfigurable MEMS FSS
Baluns feedthru to
elements
Fixedgroundplane at
base
Spiral or Circle elements
Ball Aerospace & Technologies Corp.Advanced Antenna & Video Systems
Presented at DARPA RECAP Workshop 3 October 2000
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ADV in MEMS RF SYS 100600
DARPADARPA MEM-Tenna Concept
lOBJECTIVE: To develop and demonstrateultra low-cost, light-weight, low powerphased array antenna technology
Digital Mirror Device (DMD)Projection System
Multi-RFChannels
Transmitters&
Receivers
RFIllumination
Optical
Illumination
2-D MEM Lens
DARPADARPASpecial Projects Office
Aerostat PTIR
Applications -Large, low Cost AntennasAdvanced Ship Radar
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ADV in MEMS RF SYS 100600
DARPADARPA MEMs - Enabling Technology
1
10
100
1000
Cost ($) Power (mW) Loss (dB)
MEMS
GaAs MIMIC
Ferrite
Diode
Phase ShifterTechnology
MEMS advantages lead toeconomies for large scale
arrays
10
100
1000
10000
MEM-tenna ESA Conv. Space Fed
$(K) / sq. m lbs. / sq. m
Space - fed lens eliminates cost of many T/R modules
and weight of beamformer
Space - fed optical control reduces on-array wiring
Special Projects Office
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ADV in MEMS RF SYS 100600
DARPADARPA
Photograph
Photograph Schematic
X-Band Phase Shifter
2 bits of 4-bit phase shifter
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DARPADARPA
10 GHz 2-Bit (Small) PS Performance
5.5 - 11.0 GHz Return loss > 11 dB
6.0 - 10.0 GHz Average insertion loss 0.55-0.9 dB(Arithmetic average of all 4 states)
2-Bit 10 GHz Phase Shifter - Insertion Loss
-3
-2.5
-2
-1.5
-1
-0.5
0
5 6 7 8 9 10 11
Frequency (dB)
In
sertion
Loss
(dB)
0State
22State
45State
67State
AverageLoss
2-Bit 10 GHz Phase Shifter - Return Loss
-40
-35
-30
-25
-20
-15
-10
-5
0
5 6 7 8 9 10 11
Frequency (GHz)
Return
Loss(dB)
0State
22State
45State
67State
Measured Characteristics
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DARPADARPA
5 6 7 8 9 10 11 12 13 14 15
Frequency (GHz)
-40
-35
-30
-25
-20
-15
-10
-5
0
Insert
ion
Loss(dB)
Top-calculated
Bottom-calculated
Top-measuredBottom-measured
Actuationvoltage pad
Photo of Notch Filter Circuit Measured and Calculated Resultsfor Two State Notch Filter
CapacitiveSwitch
Individual RF Switches in Tunable
Notch Filter Circuit1
3 mm
1 Develped by Licoln Lab for the RECAP progrm.
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ADV in MEMS RF SYS 100600
DARPADARPA Advanced Multi-Mode Radar
Multi-Po
lariza
tion
Adaptiv
eAnte
nna
Multiple BeamsReconfigurable Beamformer
Mode Interleaving
STAP
RF
1
RF
2
RF
3
RF
4
RF
1
RF
2
RF
3
RF
4
PRISTAR Waveform
Subarray
Time
Tx 1 RF1 RF2 RF3 RF4 RF1 RF2 RF3 RF4
STAR Waveform Utilization
Tx 2 RF
1
RF
2
RF
3
RF
4
RF
1
RF
2
RF
3
RF
4
RF
1
RF
2
RF
3
RF
4
RF
1
RF
2
RF
3
RF
4Tx 3
RF
1
RF
2
RF
3
RF
4
RF
1
RF
2
RF
3
RF
4Tx 4
Tx Rcv Tx Rcv
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ADV in MEMS RF SYS 100600
DARPADARPA Required RF MEMS Technology Activities
Process Development
Reproducibility, Yield, cost, performance, complexity
Reliability
mechanical longevity
stiction issues
Environmental Packaging
Low cost
very low loss
Transition from development to program insertions
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ADV in MEMS RF SYS 100600
DARPADARPA Summary
Advances in RF MEMS provide excitingopportunities to Inject dramatic device/componentadvances into RF SYSTEMS
Early results show technological feasibility of
applications in antennas, phase shifters, and filters Additional technology development required beforetransitioning to programs