Compact Microstrip Lowpass Filter with Ultra-Wide Stopband using Stepped-Impedance Trapezoid Resonators
Keywords:
Compact, lowpass filter, microstrip, trapezoid resonator, ultra-wideAbstract
A new microstrip lowpass filter with compact size and ultra-wide stopband is presented. The resonance properties of a microstrip main transmission line parallel loaded with the steppedimpedance trapezoid resonator are studied. Analysis results reveal that a compact size and ultra-wide stopband lowpass filter can be realized by properly introducing multiple steppedimpedance trapezoid resonators in the design. A demonstration filter with 3 dB cutoff frequency at 0.8 GHz has been designed, fabricated, and measured. Results indicate that the proposed filter is able to suppress the 17th harmonic response by 15 dB, together with a small size of 0.057 g ×0.077 g, where g is the guided wavelength at 0.8 GHz.
Downloads
References
D. Pozar, Microwave Engineering, Wiley, USA, pp. 412-415, 2005.
J.-L. Li, S.-W. Qu, and Q. Xue, “Compact microstrip lowpass filter with sharp roll-off and wide stop-band,” IEE Electron. Lett., vol. 45, no. 2, pp. 110-111, Jan. 2009.
M. Hayati, A. Sheikhi, and A. Lotfi, “Compact lowpass filter with wide stopband using modified semi-elliptic and semi-circular microstrip patch resonator,” IEE Electron. Lett., vol. 46, no. 22, pp. 1507-1509, Oct. 2010.
K. Ma and K. Yeo, “New ultra-wide stopband lowpass filter using transformed radial stubs,” IEEE Trans. Microw. Theory Tech., vol. 59, no. 3, pp. 604-611, Mar. 2011.
J. Wang, H. Cui, and G. Zhang, “Design of compact microstrip lowpass filter with ultra-wide stopband,” IEE Electron. Lett., vol. 48, no. 14, pp. 854-856, July 2012.
X. Wei, P. Wang, M. Liu, and Y. Shi, “Compact wide-stopband lowpass filter using stepped impedance hairpin resonator with radial stubs,” IEE Electron. Lett., vol. 47, no. 15, pp. 862-863, July 2011.
F. Wei, L. Chen, and X.-W. Shi, “Compact lowpass filter based on coupled-line hairpin unit,” IEE Electron. Lett., vol. 48, no. 7, pp. 379-381, Mar. 2012.
V. Velidi and S. Sanyal, “Sharp roll-off lowpass filter with wide stopband using stub-loaded coupled-line hairpin unit,” IEEE Microw. Wirel. Compon. Lett., vol. 21, no. 6, pp. 301-303, June 2011.
F. Wei, X.-W. Shi, B. Li, Q. Huang, and X. Wang, “Design of a compact microstrip low-pass filter using defected ground structure,” Microwave Opt. Technol. Lett., vol. 50, no. 12, pp. 3157-3160, Dec. 2008.
G. Al-Omair, S. Mahmoud, and A. Al-Zayed, “Lowpass and bandpass filter designs based on DGS with complementary split ring resonators,” Applied Computational Electromagnetic Society (ACES) Journal, vol. 26, no. 11, pp. 907-914, Nov. 2011.
M. Challal, A. Boutejdar, M. Dehmas1, A. Azrar, and A. Omar, “Compact microstrip low-pass filter design with ultra-wide reject band using a novel quarter-circle DGS shape,” Applied Computational Electromagnetic Society (ACES) Journal, vol. 27, no. 10, pp. 808-815, Oct. 2012.
