Aug 3, 2011 - 22â25, Jan. 2002. [4] S. H. Yeh and K.-L. Wong, âCompact dual-frequency PIFA with a chip- inductor-loaded rectangular spiral strip,â Microw.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 59, NO. 8, AUGUST 2011
choices in the type and position of reactive components. The proposed method has been successfully applied in designing monopole antenna for a mobile handset satisfying GSM900/UMTS2100/WiBro/Bluetooth requirements.
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Band-Notched UWB Antenna Incorporating a Microstrip Open-Loop Resonator James R. Kelly, Peter S. Hall, and Peter Gardner
ACKNOWLEDGMENT The authors would like to thank RadiNa Inc. Ltd. in Korea and the Brain Korea 21 project for manufacture and measurement support.
REFERENCES [1] K. L. Wong, Planar Antennas for Wireless Communications. Hoboken, NJ: Wiley, 2003, pp. 26–53. [2] Z. N. Chen, Antennas for Portable Devices. Chichester, U.K.: Wiley, 2007, p. 142. [3] P. L. Teng and K. L. Wong, “Planar monopole folded into a compact structure for very-low-profile multiband mobile-phone antenna,” Microw. Opt. Technol. Lett., vol. 33, pp. 22–25, Jan. 2002. [4] S. H. Yeh and K.-L. Wong, “Compact dual-frequency PIFA with a chipinductor-loaded rectangular spiral strip,” Microw. Opt. Technol. Lett., vol. 33, pp. 394–397, May 2002. [5] H. Choi and H. Kim, “Dual-band chip antenna design using intercoupling capacitance,” Microw. Opt. Technol. Lett., vol. 51, pp. 1467–1470, Mar. 2009. [6] J. S. McLean, “A re-examination of the fundamental limits on the radiation Q of electrically small antennas,” IEEE Trans. Antennas Propag., vol. 44, p. 672, May 1996. [7] P. Vainikainen, J. Ollikainen, O. Kivekas, and K. Kelander, “Resonator-based analysis of the combination of mobile handset antenna and chassis,” IEEE Trans. Antennas Propag., vol. 50, pp. 1433–1444, Oct. 2002. [8] A. D. Yaghjian and S. R. Best, “Impedance, bandwidth and Q of antennas,” IEEE Trans. Antennas Propag., vol. 53, pp. 1298–1324, Apr. 2005. [9] H. Choi, S. Jeon, S. Kim, and H. Kim, “Controlling resonance frequencies in antennas to achieve wideband operation,” Electron. Lett., vol. 45, pp. 716–717, Jul. 2009. [10] R. Schmitt, Electromagnetics Explained: A Handbook for Wireless/RF, EMC and High-Speed Electronics. Boston, MA: Newnes, 2002, pp. 229–230. [11] G. K. H. Lui and R. D. Murch, “Compact dual-frequency PIFA designs using LC resonators,” IEEE Trans. Antennas Propag., vol. 49, pp. 1016–1019, Jul. 2001. [12] S. Dong-Uk and P. Seong-Ook, “A triple-band internal antenna: Design and performance in presence of the handset case, battery, and human head,” IEEE Trans. Electromagn. Compat., vol. 47, pp. 658–666, Mar. 2005. [13] J. Rahola and J. Ollikainen, “Optimal antenna placement for mobile terminals using characteristic mode analysis,” in Proc. EuCAP, Nice, France, Nov. 2006, pp. 1–6. [14] M. Makimoto and S. Yamashita, Microwave Resonators and Filters for Wireless Communication Theory, Design and Application. New York: Springer, 2001, pp. 84–106. [15] M. Sagawa, K. Takahashi, and M. Makimoto, “Miniaturized hairpin resonator filters and their application to receiver front-end MIC’s,” IEEE Trans. Microw. Theory Tech., vol. 37, pp. 1991–1997, Dec. 1989. [16] V. Pathak, S. Thornwall, M. Krier, S. Rowson, G. Poilasne, and L. Desclos, “Mobile handset system performance comparison of a linearly polarized GPS internal antenna with a circularly polarized antenna,” in Proc. IEEE AP-S Int. Symp., Columbus, OH, Jun. 2003, vol. 3, pp. 666–669.
Abstract—Ultrawideband (UWB) systems require band notch filters in order to prevent sensitive components, within the front-end of the receiver, from being overloaded by strong signals. Recently, it has been shown that these filters can be integrated into the UWB antenna, to great advantage. This communication presents a new method for forming a notch band within the frequency response of a UWB antenna. An open loop notch band resonator is located on the back of the substrate, used to support the UWB monopole. The act of separating the resonator from the antenna means that they can now be designed in isolation, using the standard approach described in the literature, and then combined. A prototype was constructed and good agreement has been obtained between simulation and measurement. The radiation patterns are consistent over the frequency range of interest. Index Terms—Band-stop filters, coplanar waveguides, monopole antennas, ultrawideband (UWB) antennas.
I. INTRODUCTION There is much interest in the use of ultrawideband (UWB) signals (from 3.1 to 10.6 GHz) for short range, high-data rate communications [3]. UWB radar systems have been used to improve the detection of early stage breast cancer [1], [2]. UWB ground penetrating radar can be used to detect mines and damaged utility pipes. Interference from a strong narrowband signal, within the UWB band, could overload the receiver and band-stop filters have been suggested to mitigate for this. This filter might be a separate component, connected in series with the antenna [4], which will increase the size, weight, and complexity of the system or it could be integrated into the antenna’s feed-line [5]. A substrate integrated waveguide (SIW) cavity filter is used in [5], within the feed-line of an UWB monopole antenna, but antenna performance degradations result. An alternative is to integrate some form of band-stop filter into the radiating element. The majority of designs use a resonant slot within the planar monopole antenna [6]–[15]. Unfortunately most of the current solutions are limited by having: 1) poor return loss, i.e., >1.5 dB [5], [7], [13], [14], [25] or >2.5 dB [9], [10], [12], [16]; 2) poor gain suppression, i.e.,
