Frequency Reconfigurable Microstrip Patch Antenna

Frequency Reconfigurable Microstrip Patch Antenna

Final Project Presentation

Presented by: Mike Bly, Josh Rohman

Advisor: Dr. Prasad N. Shastry

Why Reconfigurable Antennas?Why Reconfigurable Antennas?

Practical Applications?Practical Applications?

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

Design Specifications•Microstrip patch antenna (Rogers RO3010)•2 GPS application frequencies

24 MHz Bandwidth1.575 GHz Center Frequency (Patch 1)1.227 GHz Center Frequency (Patch 2)Linear Polarization

•Inset Feed matching networkMatched to 50Ω

•MEMS preferred for switching method

System Block Diagram

Switches?

Patch 1(1.575 GHz)

Patch 2 Connected

(1.227 GHz)

Inset Feed Matches to 50

ohm

Output to Coax Connector

On

Off

Switching Method•MEMS Switch

RMSW201, RADANT MEMS0.3dB Insertion Loss @ 2GHz35dB Isolation Loss @ 2GHz1.9mm x 1.85mm package size

RMSW201 MEMS Operation•+/- 90 VGS Actuation Voltage

RMSW201 MEMS Operation•+/- 90 VGS Actuation Voltage

Implementing MEMS•RS = RD = 100kΩ•Stability

Switching Method

+5V Supply Line

DC-DC Converter MEMS Gate

Switching Method•DC-DC Converter: +5V to -90V• R2/R1 = Vout/Vref• R2 = Vout/10uA

+5VDC

-90VDC

Switching Method•DC-DC Converter: +5V to -90V

+5VDC

-90VDC

Switching Method•DC-DC Converter: +5V to -90V

+5VDC

-90VDC

Switching Method•DC-DC Converter: +5V to -90V

+5VDC

-90VDC

DC-DC Converter Timing

Implementing MEMS•Conductive epoxy, double-stick thermal

tape•Wire bonding, gold plating

MEMS Evaluation Board

MEMS Evaluation Board

MEMS Evaluation Board

MEMS Evaluation Board

MEMS Evaluation Board

Micro-Circuits, Inc.•Contact: Robert Modica

(630) 628-5764 microcir@aol.com

Patch Antenna Design Step 1

L = 30mm & W = 40.25mm L = 38.6mm & W = 40.25mm

ΔL = 0.412h*[(εeff + 0.3)(W/h + 0.264)]/[( εeff – 0.258)(W/h + 0.8)]W = c/(2fo*√((εr+1)/2))L = c/(2fo*√(εr)) – 2ΔL

Patch Antenna Design Step 2

L = 30mm & W = 40.25mm

<-Height = 1mm

Patch Antenna Design Step 3

L1 = 30mm & W = 40.25mm

Height = 1.9mmHeight = 1mm

1.575 GHz Patch Antenna Design

Simulations: 1.575 GHz Patch Antenna

Simulations: 1.575 GHz Patch Antenna•1 to 2 GHz Simulation

1.575 GHz Results

1.227 GHz Patch Antenna Design

Simulations: 1.227 GHz Patch Antenna

Simulations: 1.227 GHz Patch Antenna•1 to 2 GHz Simulation

1.227 GHz Results

Inset Feed Matching Network

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

Inset Feed Design Step 1

y0 = [Cos-1(Z0/Zin)]2*(L/π)W0 = 0.6mm (50Ω microstrip line)W1 = W0

Inset Feed Design Step 2

L = 30mm & W = 40.25mm & y0 = 10.25mm

Height = 1mm

Inset Feed 1.575Ghz Simulation

Simulations: 1.575 GHz Inset

1.575 GHz Inset Results

Inset Feed 1.227Ghz Simulation

Simulations: 1.227 GHz Inset

1.227 GHz Inset Results

Antenna System Layout

Fabricated Antenna System

Questions?

Sources:• Application Note for MAX774 DC-to-DC Converter. RadantMEMS, 2007. Web. Nov. 2011.

<http://www.radantmems.com/radantmems.data/Library/MAX774%20DC-DC%20Converter_1.2.pdf>.

• Application Note for Test & Handling of SPST RF-MEMS Switches. RadantMEMS, 2007. Web. Nov. 2011. <http://www.radantmems.com/radantmems.data/Library/App_notes_1.6.pdf>.

• 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. <http://www.radantmems.com/radantmems.data/Library/Radant-

Datasheet201_1.4.pdf>.• 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.