Tunable microstrip dual-band bandpass lter for WLAN applications
Tunable microstrip dual-band bandpass lter for WLAN applications
In this paper, based on a new stub-loaded open loop resonator, a compact microstrip dual-band bandpasslter is presented. The proposed lter is designed using two stub-loaded open loop resonators to create two pass bands at 2.39 GHz and 5.7 GHz for multimode wireless LANs applications. Two high impedance sections are used in the main loops and the internal stubs are two low impedance microstrip cells. A method is presented to control the mode resonance frequencies. By increasing the internal stubs' dimensions, the resonance frequencies are adjusted without size increment. The proposed lter has a good performance. The insertion losses at 2.39 GHz and 5.7 GHz frequencies are 0.1 dB and 0.4 dB, respectively, while the return loss at the two pass bands is better than {16.6 dB. The lter size is 251 mm 2 . The designed lter is fabricated and measured. The results show that there is a good agreement between the simulation and measurement.
___
- [1] Lee HM, Tsai CC. Dual-band lter design with exible pass band frequency and bandwidth selections. IEEE T Microw Theory 2007; 55: 1002-1009.
- [2] Sun S, Zhu L. Coupling dispersion of parallel coupled microstrip lines for dual-band lters with controllable fractional pass bandwidths. IEEE MTT-S Int Microw Symp Dig 2005; 4: 2195-2198.
- [3] Zhang YP, Sun M. Dual-band microstrip bandpass lter using stepped-impedance resonators with new coupling scheme. IEEE T Microw Theory 2006; 54: 3779-3785.
- [4] Weng MH, Wu HW, Su YK. Compact and low loss dualband bandpass lter using pseudo-interdigital stepped impedance resonators for WLANs. IEEE Microw Wireless Compon Lett 2007; 17: 187-189.
- [5] Kuo JT, Yeh TH, Yeh CC. Design of microstrip bandpass lters with a dual-pass band response. IEEE T Microw Theory 2005; 53: 1331-1337.
- [6] Ren L, Huang H. Dual-band bandpass lter based on dual-plane microstrip/interdigital DGS slot structure. Electron Lett 2009; 45: 1077-1079.
- [7] Tseng CH, Shao HY. A new dual-band microstrip bandpass lter using net-type resonators. IEEE Microw Wireless Compon Lett 2010; 20: 196-198.
- [8] Jiang M, Chang LM, Chin A. Design of dual-pass band microstrip bandpass lters with multi-spurious suppression. Microw Wireless Compon Lett 2010; 20: 199-201.
- [9] Chen X, Han G, Ma R, Gao J, Zhang W. Design of balanced dual-band bandpass lter with self-feedback structure. ETRI J 2009; 31: 475-477.
- [10] Mondal P, Mandal MK. Design of dual-band bandpass lters using stub-loaded open-loop resonators. IEEE T Microw Theory 2008; 56: 150-155.
- [11] Hayati M, Noori L. Compact dual-band bandpass lter with ultra wide stopband using open loop resonator loaded by T-shape and open stubs. IEICE 2011; 8: 1168-1173.
- [12] Hong JS, Lancaster M J. Microstrip Filters for RF/Microwave Applications. 2nd ed. New York, NY, USA: Wiley, 2001.
- [13] Marimuthu J, Abbosh AM, Henin B. Planar microstrip bandpass lter with wide dual-bands using parallel-coupled lines and stepped impedance resonators. Prog Electromagn Res C 2013; 35: 49-60.
- [14] Khajavi N, Makki S, Majidifar S. Design of high performance microstrip dual-band bandpass lter. Radioeng 2015; 24: 32-38.
- [15] Hayati M, Noori L, Adinehvand A. Compact dual-band bandpass lter using open loop resonator for multimode WLANs. Electron Lett 2012; 48.