1. A Reduced Frequency Printed Quasi-Yagi Antenna Symmetrically Loaded with Meander Open Complementary Split Ring Resonator (MOCSRR) Elements Joshua Anderson Kai Johnson Cody Satterlee Andrew Lynch Benjamin D. Braaten* ECE Department North Dakota State University Fargo, ND, USA.

2. 1) Introduction and Background 2) The Reduced frequency Quasi-Yagi Antenna 3) Measurement and Simulation Results 4) Discussion and Guidelines 5) Conclusion Topics

3. Introduction and Background [1] A. Velez, F. Aznar, J. Bonache, M. C. Valazquez-Ahumada, J. Martel and F. Martin, “Open complementary split ring resonators (OCSRRs) and their application to wideband CPW band pass filters,” IEEE Microwave and Wireless Component Letters, vol. 19, no. 4, pp. 197-199, Apr. 2009. The open complementary split ring resonator (OCSRR) element [1]:

4. [2] B. D. Braaten, “A novel compact UHF RFID tag antenna designed using series connected open complementary split ring resonator (OCSRR) particle,” IEEE Transactions on Antennas and Propagation, vol. 58, no. 11, Nov. 2010, pp. 3728-3733. The OCSRR element has been used to design small resonant antennas [2]: Introduction and Background

5. The meander open complementary split ring resonator (MOCSRR) element [3]: [3] B. D. Braaten and M. A. Aziz, “Using meander open complementary split ring resonator (MCOSRR) particles to design a compact UHF RFID tag antenna,” IEEE Antenna and Wireless Propagation Letters, vol. 9, 2010, pp. 1037-1040.

6. Introduction and Background CPW structure used to measure the MOCSRR element:

7. Introduction and Background Printed MOCSRR element: S-parameters [4]: L eq = 9.25 nH C eq = 5.1 pF f o = 735 MHz [4] B. D. Braaten, M. A. Aziz, M. J. Schroeder and H. Li, “Meander open complementary split ring resonator (MOCSRR) particles implemented using coplanar waveguides,” Proceedings of the IEEE International Conference on Wireless Information Technology and Systems, Honolulu, Hawaii, Aug. 28 – Sep. 3, 2010.

8. Reduced Frequency Quasi-Yagi A = 131.4 mm B = 145.98 mm a = 22.27 mm b = 17.7 mm c = 1.3 mm d1 = 52.0 mm f = 40.98 mm i = 66.0 mm j = 12.0 mm k = 41.0 mm m = 5.8 mm n = 9.08 mm u = 4.45 mm α = 48.28 mm β = 15.91 mm Substrate: Thickness: 1.27 mm Permittivity: 10.2

9. Reduced Frequency Quasi-Yagi W = 6.88 mm H = 6.73 mm d2 = 2.45 mm g = 0.22 mm h = 4.53 mm p = 0.26 mm q = 0.32 mm r = 1.94 mm s = 0.17 mm t = 0.27 mm v = 0.19 mm L eq = 5.25 nH C eq = 5.6 pF f o = 2.2 GHz Approx. twice the operating frequency.

10. Measurement and Simulation Results Original unloaded quasi-yagi antenna [5].New loaded quasi-yagi antenna. [5] S. Chen and P. Hsu, “Broadband microstrip-fed modified quasi-yagi antenna,” Wireless Communications and Applied Computational Electromagnetics, Aug. 2005, pp. 208-211.

11. Measurement and Simulation Results Closer image of the element.

12. Measurement and Simulation Results Measuring the original quasi-yagi antenna.Operating frequency of 1.2 GHz.

13. Measurement and Simulation Results Measuring the loaded quasi-yagi antenna. 35% lower operating frequency Simulated: 735 MHz Measured: 765 MHz.

14. Measurement and Simulation Results x-z plane at 735 MHzy-z plane at 735 MHz Simulated gain at 1.18 GHz was 4.1 dBi (unloaded antenna) Simulated gain at 735 MHz was -5.5 dBi (loaded antenna)

15. Discussion and Guidelines The input impedance of the loaded and unloaded dipole above was finally computed: At 800 MHz Z eq1 = 17.2 – j97.0 Ω (without loading elements) Z eq2 = 104.0 + j126.0 Ω (with loading elements) Z eq = 102 Ω at 800 MHz (MOCSRR element) Im(Z eq1 - Z eq2 ) = Im(ΔZ) ≈ 233.0 Ω ≈ 2Zeq

16. 1) Intro. and background on the MOCSRR elements was presented. 2) The reduced frequency Quasi-Yagi antenna was introduced. 3) Measurement and simulation results were compared. 4) Initial discussion and guidelines on loading the antenna with MOCSRR elements was presented. Conclusion

17. Thank you for listening! Questions?