Miniaturized Microstrip Lowpass Filter with Ultra-Wide Stopband
Keywords:
Lowpass filter and microstrip, ultra-wide stopbandAbstract
A new microstrip lowpass filter with compact size and ultra-wide stopband is presented. Using triangular patch resonators and butterfly resonator with four 45° radial “wing” patches, the introduced filter can successfully realize compact design and ultra-wide stopband. To further reduce the circuit size of the filter, the meander transmission lines are also adopted in the design. A demonstration filter with 3 dB cutoff frequency at 1.6 GHz has been designed, fabricated, and measured. Measured results show that the lowpass filter has an ultra-wide stopband bandwidth of 153.9 %, which is able to suppress the 11th harmonic response. Furthermore, it also has a small size of 14 ? 15 mm2, which corresponds to 0.114 ?g ? 0.122 ?g, where ?g is the guided wavelength at 1.6 GHz.
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References
D. M. Pozar, Microwave Engineering, 3rd ed. New York: Wiley, Ch. 7, pp. 412-415, 2005.
L. Li, Z. -F. Li, and J. -F. Mao, “Compact lowpass filters with sharp and expanded stopband using stepped impedance hairpin units,” IEEE Microw. Wirel. Compon. Lett., vol. 20, no. 6, pp. 310-312, June 2010.
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. -X. Ma and K. -S. Yeo, “New ultra-wide stopband low-pass filter using transformed radial stubs,” IEEE Trans. Microw. Theory Tech., vol. 59, no. 3, pp. 604-611, Mar. 2011.
K. -Y. Zhao, L. Li, and Y. -M. Wang, “A novel lowpass filter using three corner-cutting T-shaped compact microstrip resonator cells,” Engineering and Technology (S-CET), 2012.
X. -B. Wei, P. Wang, M. -Q. 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.
J. -P. Wang, H. -F. Cui, and G. Zhang, “Design of a compact microstrip lowpass filter with ultra-wide stopband,” IEE Electron. Lett., vol. 48, no. 14, pp. 854-856, July 2012.
A. Bouteidar, A. Batmanov, A. Omar, and E. Burte, “Design of compact low-pass filter using cascaded arrowhead-DGS and multilayer-technique,” Asia-Pacific Microwave Conf., pp. 1-4, Dec. 2008.
S. Rehman, A. F. Sheta, and M. A. Alkanhal, “Compact bandpass filters with bandwidth control using defected ground structure (DGS),” Appl. Comp. Electro. Society (ACES) Journal, vol. 26, no. 7, pp. 624-630, July 2010.
F. Karshenas, A. R. Mallahzadeh, and J. Rashed-Mohassel, “Size reduction and harmonic suppression of parallel coupled-line bandpass filters using defected ground structure,” Appl. Comp. Electro. Society (ACES) Journal, vol. 25, no. 2, pp. 149-155, Feb. 2010.
M. Hayati, H. Asadbeigi and A. Sheikhi “Microstrip lowpass filter with high and wide rejection band,” IEE Electron. Lett., vol. 48, no. 19, pp. 1217-1219, Sep. 2012.
