UWB Monopole Antenna with Switchable Band-Notch Characteristic Using a Novel MEMS Afloat
Keywords:
MEMS U-shaped afloat, switchable band notch, UWB antennaAbstract
In this paper, a novel microelectro-mechanical system (MEMS) U-shaped afloat is designed and used instead of a simple slot to activate and deactivate the band notch characteristic of an ultra wideband (UWB) monopole antenna at the WLAN band (5.15-5.825 GHz) without extra DC bias lines. The novelty of this work is design of MEMS afloat that can stay in down state permanently. When the dc actuation voltage, about 20 volts, is applied to the microstrip center line, the ?/2 long U-shaped afloat moves down and creates a slot (resonating element) in its vacant place. Whereas no voltage is applied, the afloat remains in the up position and serves as a part of the antenna, which eliminates the resonance. The proposed design for MEMS afloat has least negative effect on gain, reflection coefficient, and pattern of the antenna. The gain of the antenna is about 3.2 dBi over the entire UWB frequency band (3.1-10.6 GHz), while it decreases sharply over 7 dB at the rejection band. More-over, the time-domain characteristics of the antenna is investigated, which shows 1 ns delay over the UWB frequency band for 20 cm. Due to a novel afloat design, the addition of the resonance element does not affect on the radiation performance, reflection coefficient, gain, and group delay of the antenna outside of notched band frequencies.
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References
Federal Communications Commission Re-vision of Part 15 of the Commission’s Rules Regarding Ultra-wideband Transmission System” Tech. Rep., ET-Docket 98-153, FCC02-48, 2002.
R. Chair, A. A. Kishk, K. F. Lee, C. E. Smith, and D. Kajfez, “Microstrip line and CPW fed ultrawideband slot antennas with U-shaped tuning stub and reflector,” Progress In Electromagnetics Research, vol. 56, pp. 163-182, 2006.
D. Chen and C. H. Cheng, “A novel compact ultrawideband (UWB) wide slot antenna with via holes,” Progress In Electromagnetics Research, vol. 94, pp. 343-349, 2009.
K. P. Ray and Y. Rang, “Ultra wideband printed elliptical monopole antennas,” IEEE Transactions on Antennas and Propagation, vol. 55, no. 4, pp. 1189-1192, 2007.
N. Ojaroudi, M. Ojaroudi, and Sh. Amiri, “Enhanced bandwidth of small square monopole antenna by using inverted U-shaped slot and conductor-backed plane,” Applied Computational Electromagnetics Society (ACES) Journal, vol. 27, no. 8, pp. 685- 690, Aug. 2012.
R. Fallahi, A.-A. Kalteh, and M. Golparvar Roozbahani, “A novel UWB elliptical slot antenna with band-notched characteristics,” Progress In Electromagnetics Research, vol. 82, pp. 127-136, 2008.
Y. J. Cho, K. H. Kim, D. H. Choi, S. S. Lee, and SO. Park, “A miniature UWB planar monopole antenna with 5-GHz band-rejection filter and the time-domain characteristics,” IEEE Trans Antennas Propag., vol. 54, no. 5, pp. 1453-1460, 2006.
T. P. Vuong, A. Ghiotto, Y. Duroc, and S. Tedjini, “Design and characteristics of a small U-slotted planar antenna for IR-UWB,” Microwave Opt. Technol. Letters, vol. 49, iss. 7, pp. 1727-1731, 2007.
M. Majidzadeh and C. Ghobadi, “Compact microstrip fed monopole antenna with modified slot ground plane for UWB applications,” Applied Computational Electromagnetics Society (ACES) Journal, vol. 27, no. 10, pp. 801-807, Oct. 2012.
S. Khan, J. Xiong, and S. He, “Low profile and small size frequency notched planar monopole antenna from 3.5 to 23.64 GHz,” Microwave Opt. Technol. Letters, vol. 50, iss. 1, pp. 235-236, Jan. 2008.
R. Zaker, C. Ghobadi, and J. Nourinia, “Novel modified UWB planar monopole antenna with variable frequency band-notched function,” IEEE Antennas Wireless Propag. Letters, vol. 7, pp. 112- 114, 2008.
W. Chen and K. Yang, “CPW-fed planar ultrawideband antenna having a frequency bandrejected function,” Proc. Int. Conf. TENCON2007, pp. 1-3, 2007.
Y. Li, W. Li, and W. Yu, “A switchable UWB slot antenna using SIS-HSIR and SIS-SIR for multimode wireless communications applications,” Applied Computational Electromagnetics Society (ACES) Journal, vol. 27, no. 4, pp. 340-351, Apr. 2012.
V. A. Shameena, M. N. Suma, K. Raj Rohith, P. C. Bybi, and P. Mohanan, “Compact ultra-wideband planar serrated antenna with notch band ON=OFF control,” Electron. Lett., vol. 42, no. 23, pp. 1323- 1324, Nov. 2006.
S. Nikolaou, N. D. Kingsley, G. E. Ponchak, J. Papapolymerou, and M. Tentzeris, “UWB elliptical monopoles with a reconfigurable band notch using MEMS switches actuated without bias lines,” IEEE Trans. Antennas Propag., vol. 57, no. 8, pp. 2242- 2251, 2009.
D.-M. Fang, S. Fu, Y. C. Yong, and X.-L. Zhao, “Surface micromachined RF MEMS variable capacitor,” Microelectronics Journal, vol. 38, no. 8-9, pp. 855-859, 2007.
W.-S. Lee, D.-Z. Kim, K.-J. Kim, and J. W. Yu, “Wideband planar monopole antennas with dual band-notched characteristics,” IEEE Trans. Microw. Theory Tech., vol. 54, no. 6, pp. 2800-2806, Jun. 2006.
