In this paper, a new printed ultra-wideband (UWB) power divider with notched band using square ring multiple-mode resonator (SRMMR) is presented. The characteristics of the proposed SRMMR are investigated by using even- and odd-mode analysis. Then, the initial UWB performance is achieved by introducing SRMMR to the basic Wilkinson power divider. Finally, a pair of parallel coupled lines is embedded into the SRMMR to achieve a desired notched band inside the UWB passband. The central frequency and the bandwidth of the notched band can be easily controlled by the electrical length and coupling coefficient of the coupled lines. To validate the design concept, a novel printed UWB power divider with notched band centered at frequencies of 5.8 GHz is designed and measured. The simulated and measured results indicate that it has a low insertion loss and good return loss performance at all the three ports, and a high isolation between the two output ports across the UWB bandwidth from 3.1 to 10.6 GHz with a small size of 0.46λg×0.69λg, where λg is the guided wavelength at 6.85 GHz.
1. Zhao, J. D., J. P. Wang, and J. L. Lin, "Compact UWB bandpass filter with triple notched bands using parallel U-shaped defected microstrip structure," IET Electron. Lett., Vol. 50, No. 2, 89-91, 2014. doi:10.1049/el.2013.3077
2. Lee, S. W., C. S. Kim, K. S. Choi, J. S. Park, and D. Ahn, "A general design formula of multi-section power divider based on singly terminated filter design theory," IEEE MTTS-S Int. Microwave Symp. Dig., Vol. 2, 1297-1300, Phoenix, AZ, USA, 2001.
3. Xue, Q. and K. Song, "Ultra-wideband coaxial-waveguide power divider with flat group delay response," IET Electron. Lett., Vol. 46, No. 17, 1236-1237, 2010. doi:10.1049/el.2010.1295
4. Wong, S. W. and L. Zhu, "Ultra-wideband power divider with good in-band splitting and isolation performances," IEEE Microw. Wirel. Compon. Lett., Vol. 18, No. 8, 518-520, 2008. doi:10.1109/LMWC.2008.2001009
5. Song, K.-J. and Q. Xue, "Novel Ultra-wideband (UWB) multilayer slotline power divider with bandpass response," IEEE Microw. Wirel. Compon. Lett., Vol. 20, No. 1, 13-15, 2010. doi:10.1109/LMWC.2009.2035951
6. Wang, J., W. Hong, H.-J. Tang, Y. Zhang, J.-X. Chen, and J.-Y. Zhou, "Ultra-wideband bandpass filter with multiple frequency notched bands based on SIW and SIR technology," Proceedings of the 36th European Microwave Conference, 268-271, 2009.
7. Abbosh, A. M., "Multilayer bandstop filter for ultra wideband systems," IET Microw. Antennas Propag., Vol. 3, No. 1, 130-136, 2009. doi:10.1049/iet-map:20070294
8. Matthaei, G., L. Young, and E. Jones, Microwave Filters, Impedance-matching Network, and Coupling Structures, 219-220, Artech House, Norwood, MA, USA, 1980.
9. Pozar, D. M., Microwave Engineering, 3th Ed., 185-187, Wiley, New York, 2005.