Technical Presentation: April 27, 2012 Sponsored by: Website: seniordesign.engr.uidaho.edu/ /panelantenna

The Team Allan Davis: Project Lead Carlos Gonzalez: Budget/Resource Manager Cooper McBride: Website Developer 2

Objective Design, fabricate and test a 900-Mhz directional panel antenna for Schweitzer Engineering Laboratories 3

Applications Radios provide comm channels for electric utility protection, monitoring, and control Economical alternative to fiber-optic cable Backup primary protection channels Many more possible applications of wireless communications for critical infrastructure 4

What SEL Needs An antenna that will have performance similar to antennas that are currently supplied by outside sources The antenna will be used with the SEL-3031 Serial Radio Transceiver 5

Yagi Antenna SEL is currently selling directional Yagi antennas with the SEL-3031 An example of a 5-element Yagi is shown here 6

Design Process Research of existing antenna designs Computer simulations using Agilent EMPro software Finite-difference time-domain (FDTD) Finite element method (FEM) We fabricated several design variations based on our simulation results We tested the designs with different backplate spacings using SELs RFI chamber 7

Final Design Directional Bowtie Antenna 8

Far-Field Radiation Patterns 9 Horizontal Plane TestedSimulated Main LobeSide LobesMain LobeBack Lobe

Specifications Operating frequency range: MHz Directional Used for either vertical or horizontal polarization Gain ≈ 6 dBi 3-dB Beamwidth ≈ 65° Designed using printed circuit board technology FR-4 substrate Backplate spacing: 83 mm (λ/4) 10

Challenges during the project Software PC compatibility issues Convergence issues Simulation times ranged from ½ hour to 7 hours Correctly interpreting simulation results Extensive trial and error to get useable data Limited availability of RFI chamber 11

Recommendations for future work Investigate using an array of 2-4 bowtie elements for improved directionality Match the input impedance to 50 Ω using a microstrip matching network (quarter-wave impedance transformer, etc.) The antenna should be characterized by a professional antenna laboratory before production 12

Special Thanks Advisors: Dr. Greg Donohoe Dr. Touraj Assefi Sponsors: Eric Sagen Henry Loehner Dr. Jeff Young Dr. Chris Wagner 13

Questions? 14