dual-band probes with broadband diplexers for 2-port...
TRANSCRIPT
Dual-Band Probes with Broadband Diplexers
for 2-Port Measurement up to 170 GHz
Florian Boes and Georg GramlichKarlsruhe Institute of Technology, Germany
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Outline
Why including Diplexers in RF Probe
Motivation
Diplexer TheoryWorkflow
Filter Design
Scale Down Prototype
Measurement Example
Verification
Conclusion Outlook
Roundup
3
Motivation• Limited measurement bandwidth
– Frequency extension module– Coaxial cable– Waveguide
• Multiple measurements required– Reconnecting sensitive equipment– Warmup– Calibration
Typical waveguide bands for mmW and sub-mmW measurements
coaxial0-110 GHz
WR6110-170 GHz
WR5140-220 GHz
WR3220-325 GHz
WR2325-500 GHz
DC – 110 GHz
110 – 170 GHz
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Motivation• Limited measurement bandwidth
– Frequency extension module– Coaxial cable– Waveguide
• Multiple measurements required– Reconnecting sensitive equipment– Warmup– Calibration
Typical waveguide bands for mmW and sub-mmW measurements
coaxial0-110 GHz
WR6110-170 GHz
WR5140-220 GHz
WR3220-325 GHz
WR2325-500 GHz
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• Passive dual band probe• Integrated diplexer
into probe housing– 1.0 mm connector (DC-110 GHz)– WR-06 connector (110-170 GHz)
mmW Head Controller
DUT
DC-170 GHz probe with integrated diplexerWR-06
Extension Module40 MHz - 110 GHz
Extension Module110 - 170 GHz
1 mm coax
WR-06
Extension Module40 MHz - 110 GHz
Extension Module110 - 170 GHz
1 mm coax
Dual Band On-Wafer Probe• Combining adjacent
frequency bands within one single measurement
• using existing measurement hardware
• 4-port NWA for 2-port measurement
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Outline
Why including Diplexers in RF Probe
Motivation
Diplexer TheoryWorkflow
Filter Design
Scale Down Prototype
Measurement Example
Verification
Conclusion Outlook
Roundup
7
Modified Tables for Optimum DiplexersDesign Goals:
• Low Loss• Return Loss < -10 dB• Isolation 20 dB
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Modified Tables for Optimum DiplexersDesign Goals:
• Low Loss• Return Loss < -10 dB• Isolation 20 dB
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Suspended Stripline (SSL)• Good shielding
– Embedded in split-block
• Most of the field components in air
– Low loss– Low dispersion
• Single mode (f < 200 GHz)• Wide impedance range
low impedancehigh impedance
MS GCPW SSL
Zmin 8 Ω 10 Ω 8 Ω
Zmax 132 Ω 147 Ω 183 Ω
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SSL Transitions
WR06 waveguide• Return Loss < -15 dB• 110 – 170 GHz
1.0 mm coax• Return Loss < -25 dB• DC – 110 GHz
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SSL Transition – Probe Pad• SSL GCPW Infinity Probe• Return Loss < -25 dB
top bottom split-block
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400 µm
300 µm via fence
Layerstack – FormFactor Membrane• Via fence
– Suppress substrate modes– Electrical connection of split-block parts
12 µm sub 2
20 µm sub 1
15 µm sub 0
6 µm met 2
5 µm met 1
• Milled wedge– Cuts part of the membrane– Replacement of via in sub 0
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Low Pass Filter DesignStepped impedance filter
• Series inductance high impedance line• Parallel capacitor low impedance line• Quasi-lumped approach: l = λ/8
– neglect parasitic effects
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Band Pass Filter DesignCoupled resonator filter
• λ/2 transmission line• Capacitive coupling
Equivalent circuit based on 3D EM simulations• Objective: Find link between CST parameers and ADS components
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Diplexer with BPF – DC-110-170 GHz Diplexer design
• Stepped impedance LPF• Coupled Resonator BPF
T-Junction: individual parameter adjustment
• Phase relation LPF – BPF• Cin BPF• Line1 length LPF
Cin
ϕLPF-BPF
line1
3D EM Simulations
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High Pass FilterQuasi-lumped elements filter
• Series capacities– End-coupled line sections
on opposite sides of the PCB– C1 = 6 fF– C2 = 5 fF– Cpar = 0.3 fF
• Parallel inductances– Short-circuited
high impedance stub– L1 = 140 pH
• finite length of T-junction– Requires transmission-lines
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Diplexer DC-110-170 GHzDiplexer design
• Stepped impedance LPF• Quasi concentrated HPF
T-Junction:• Phase relation LPF – HPF• Cin HPF• Transmission line at HPF input
– Decouple T-junction & HPF• Line1 length LPF
3D EM simulation:• Well matched < -20 dB• Low insertion loss• Sharp separation of frequency bands
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Outline
Why including Diplexers in RF Probe
Motivation
Diplexer TheoryWorkflow
Filter Design
Scale Down Prototype
Measurement Example
Verification
Conclusion Outlook
Roundup
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Scaled down by ×10• DC-11-17 GHz• Rogers RO4003C
– 508 µm thickness
• SMA connectors• Easy to manufacture• Easy to measure
Scaled Down Prototype: DC-11-17 GHz
500
µm
low impedance
4 mm
3 m
m
high impedance
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Outline
Why including Diplexers in RF Probe
Motivation
Diplexer TheoryWorkflow
Filter Design
Scale Down Prototype
Measurement Example
Verification
Conclusion Outlook
Roundup
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ConclusionOn-wafer probe with integrated diplexer
• Combining adjacent frequency bands within one single measurement
• Using measurement equipment
Diplexer design method• Modified tables & Equivalent circuits• Optimization with >25 parameters
Outlook• Realization and characterization
of dipelxers DC-110-170 GHz• Integration into on-wafer probe housing
mmW Head Controller
DUT
DC-170 GHz probe with integrated diplexerWR-06
Extension Module40 MHz - 110 GHz
Extension Module110 - 170 GHz
1 mm coax
WR-06
Extension Module40 MHz - 110 GHz
Extension Module110 - 170 GHz
1 mm coax
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Thank You!
For questions, please contact:Florian Boes
Karlsruhe Institute of TechnologyInstitute of Radio Frequency Engineering
and Electronics