Frequency Reconfigurable Microstrip Patch Antenna

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Frequency Reconfigurable Microstrip Patch Antenna

• Final Project Presentation

Presented by Mike Bly, Josh RohmanAdvisor
Dr. Prasad N. Shastry
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Why Reconfigurable Antennas?Practical
Applications?
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Presentation Outline

• Design Specifications
• MEMS Switch Implementation
• Linear Patch Antenna Design
• Antenna Simulations
• Inset Feed Matching Network

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Design Specifications

• Microstrip patch antenna (Rogers RO3010)
• 2 GPS application frequencies
• 24 MHz Bandwidth
• 1.575 GHz Center Frequency (Patch 1)
• 1.227 GHz Center Frequency (Patch 2)
• Linear Polarization
• Inset Feed matching network
• Matched to 50O
• MEMS preferred for switching method

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System Block Diagram
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Switching Method

• MEMS Switch
• RMSW201, RADANT MEMS
• 0.3dB Insertion Loss _at_ 2GHz
• 35dB Isolation Loss _at_ 2GHz
• 1.9mm x 1.85mm package size

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RMSW201 MEMS Operation

• /- 90 VGS Actuation Voltage

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RMSW201 MEMS Operation

• /- 90 VGS Actuation Voltage

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Implementing MEMS

• RS RD 100kO
• Stability

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Switching Method
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Switching Method

• DC-DC Converter 5V to -90V
• R2/R1 Vout/Vref
• R2 Vout/10uA

5VDC
-90VDC
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Switching Method

• DC-DC Converter 5V to -90V

5VDC
-90VDC
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Switching Method

• DC-DC Converter 5V to -90V

5VDC
-90VDC
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Switching Method

• DC-DC Converter 5V to -90V

5VDC
-90VDC
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DC-DC Converter Timing
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Implementing MEMS

• Conductive epoxy, double-stick thermal tape
• Wire bonding, gold plating

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MEMS Evaluation Board
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MEMS Evaluation Board
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MEMS Evaluation Board
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MEMS Evaluation Board
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MEMS Evaluation Board
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Micro-Circuits, Inc.

• Contact Robert Modica
• [phone]
• microcir_at_aol.com

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Patch Antenna Design Step 1
?L 0.412h(eeff 0.3)(W/h 0.264)/( eeff
0.258)(W/h 0.8) W c/(2fov((er1)/2)) L
c/(2fov(er)) 2?L
L 30mm W 40.25mm
L 38.6mm W 40.25mm
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Patch Antenna Design Step 2
lt-Height 1mm
L 30mm W 40.25mm
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Patch Antenna Design Step 3
Height 1.9mm
Height 1mm
L1 30mm W 40.25mm
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1.575 GHz Patch Antenna Design
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Simulations 1.575 GHz Patch Antenna
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Simulations 1.575 GHz Patch Antenna

• 1 to 2 GHz Simulation

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1.575 GHz Results
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1.227 GHz Patch Antenna Design
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Simulations 1.227 GHz Patch Antenna
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Simulations 1.227 GHz Patch Antenna

• 1 to 2 GHz Simulation

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1.227 GHz Results
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Inset Feed Matching Network
INSET FEED INSET FEED        
Freq Length(mm) Width(mm) Er Ereff Zo
1.227 34.06 40.25 10.2 9.818024134 47.16779462
           
1.575 30 40.25 10.2 9.818024134 67.47522359
           
Zin(real) Zin(imag) Wo(mm) Yo(mm) Pi  
135.902 -14.159 0.59567 10.2 3.14159  
           
290.732 -28.368 0.59567 10.2 3.14159  
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Inset Feed Design Step 1
y0 Cos-1(Z0/Zin)2(L/p) W0 0.6mm (50?
microstrip line) W1 W0
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Inset Feed Design Step 2
Height 1mm
L 30mm W 40.25mm y0 10.25mm
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Inset Feed 1.575Ghz Simulation
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Simulations 1.575 GHz Inset
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1.575 GHz Inset Results
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Inset Feed 1.227Ghz Simulation
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Simulations 1.227 GHz Inset
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1.227 GHz Inset Results
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Antenna System Layout
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Fabricated Antenna System
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Questions?
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Sources

• Application Note for MAX774 DC-to-DC Converter.
  RadantMEMS, 2007. Web. Nov. 2011.
  lthttp//www.radantmems.com/radantmems.data/Librar
  y/MAX77420DC-DC20Converter_1.2.pdfgt.
• Application Note for Test Handling of SPST
  RF-MEMS Switches. RadantMEMS, 2007. Web. Nov.
  2011. lthttp//www.radantmems.com/radantmems.data/
  Library/App_notes_1.6.pdfgt.
• Balanis, Constantine A. Antenna Theory Analysis
  and Design. 3rd ed. Hoboken, NJ John Wiley,
  2005. Print.
• DeSignor, Jessica A., and Jayanti Venkataraman.
  "Reconfigurable Dual Frequency Microstrip Patch
  Antenna Using RF MEMS Switches." IEEE Xplore.
  May 2007. Web. 20 Sept. 2011.
• Rebeiz, Gabriel M., and Jeremy B. Muldavin. "RF
  MEMS Switches and Switch Circuits." IEEE Xplore.
  Dec. 2001. Web. 20 Sept. 2011.
• SPST, High-Isolation, RF-MEMS Switch DC to 20
  GHz. RadantMEMS, 2007. Web. 28 Oct. 2011.
  lthttp//www.radantmems.com/radantmems.data/Librar
  y/Radant-Datasheet201_1.4.pdfgt.
• Yang, Songnan, Chunna Zhang, Helen K. Pan, Aly E.
  Fathy, and Vijay K. Nair. "Frequency
  Reconfigurable Antennas for Multiradio Wireless
  Platforms." IEEE Microwave Magazine (2009)
  67-84. Print.