1. UWB Antenna Ryan Clarke Roshini Karunaratne Chad Schrader Advisor: Ray Kwok

2. Objectives Design UWB antenna for hand held communication device (walkie-talkie) Use Iterative simulation to arrive at design

3. Specifications 225 – 400 MHz VSWR < 1.5 : 1 Efficiency > 75% Proximity Insensitive Broadband

4. Design Issues Small enough for a handheld device (H = 10”, W = 3”, T = 1”) Broadband High Bandwidth factor (~70%) Non-dispersive

5. Antenna Topologies Considered Diamond Dipole PIFA (Planar Inverted-F Antenna) Dual L-shaped Monopole

6. Diamond Dipole Poor frequency response for 225 – 400 MHz Dimensions too big

7. PIFA Poor frequency response for 225 – 400 MHz Dimensions too big

8. Dual L-Shaped Monopole (Success!) VSWR < 1.9 for 270 – 400 MHz Efficiency Omni-directional

9. Simulation Results Optimized dimensions VSWR Radiation Pattern E-fields and H-fields

10. Optimized Dimensions Dimensions optimized by simulation software H = 236mm, 9.3in W = 31.5mm, 1.24in Pipe diameter, d = 7.5mm, 0.3in

12. VSWR VSWR < 1.9 for 270.9 – 404.3 MHz VSWR < 1.5 not achieved Mid-band VSWR minimum is ~ 1.7

14. Radiation Pattern Omni-directional f = 225 MHz, Gain[phi] = 5.2 dB f = 350 MHz, Gain[phi] = 6.0 dB f = 400 MHz, 3.5 dB < Gain[phi] < 6.9 dB

15. F = 225 MHz

17. F = 350 MHz

19. F = 400 MHz

21. E-Fields and H-Fields Distribution at corners Surface current Proximity sensitivity

25. Construction Copper pipe –Best available conductor Ground plane –Large as possible (can’t do infinite) Insulators – Lowest ε r, rubber (ε r = 2) Coaxial cable and connectors –APC7, N-type

26. Costs Copper tube, $12/ft. Ground plane, $5-$10 Mounting hardware, $2 Total Cost, $30 - $35

27. Testing Network analyzer >>> return loss curve Proximity sensitivity Radiation pattern

28. Conclusion Simulated double-L monopole antenna Simulation results encouraging Prototype construction in progress

29. The End. Questions?