Efficient Microstrip Diplexer Employing a New Structure of Dual-Mode Bandpass Filter

Authors

  • Ibrahim A. Alnagar Electronics and Electrical Communications Engineering Dept., Faculty of Engineering, Tanta University, Tanta 31527, Egypt.
  • Nessim M. Mahmoud Electronics and Electrical Communications Engineering Dept., Faculty of Engineering, Tanta University, Tanta 31527, Egypt.
  • Salah A. Khames Electronics and Electrical Communications Engineering Dept., Faculty of Engineering, Tanta University, Tanta 31527, Egypt.
  • Amr H. Hussein Electronics and Electrical Communications Engineering Dept., Faculty of Engineering, Tanta University, Tanta 31527, Egypt,Communications and Electronics Engineering Dept., Higher Institute of Engineering and Technology, New Damietta, Egypt.

Keywords:

Band pass filter (BPF), Diplexer, Impedance matching, Dual-mode resonator (DMR)

Abstract

In this paper, a highly efficient design for microstrip diplexer employing a new configuration of dual-mode squared shape bandpass filters is introduced. The proposed diplexer consists of two dual-mode bandpass filters (BPFs), a matching network, which is utilized to ensure that the two BPFs and the antenna port are properly matched resulting in good isolation between the transmitter (Tx) and the receiver (Rx) branches. For the proposed BPFs, the transmission zeros of each BPF are adjusted to the nearest passband center frequency, which makes them very selective to achieve high isolation between the Tx and Rx frequencies. This also provides a low-frequency space ratio and low insertion loss. The proposed diplexer improves the channel isolation, bandwidth with compact size of . Based on this structure, the proposed diplexer has good insertion losses of about  and  at transmit frequency  and receive frequency , respectively. The achieved fractional bandwidth is  at  and  at . The achieved simulated isolation levels are  and  for Tx and Rx frequencies, respectively. The proposed diplexer is useful for several wireless communication applications such as WLAN, GPS and global mobile system (GMS).

References

. Zhou, Y.g., et al., High isolation microstrip diplexer with enhanced stopband characteristics for GSM and WLAN application. 2013. 55(12): p. 2990-2993.

. Qiang, T., C. Wang, and N.-Y.J.S.-S.E. Kim, High-performance and high-reliability SOT-6 packaged diplexer based on advanced IPD fabrication techniques. 2017. 134: p. 9-18.

. Pozar, D.M., Microwave engineering. 2011: John wiley & sons.

. Bui, D., et al., Compact low‐loss microstrip diplexer for RF energy harvesting. 2017. 53(8): p. 552-554.

. Chuang, M.-L., M.-T.J.I.M. Wu, and W.c. letters, Microstrip diplexer design using common T-shaped resonator. 2011. 21(11): p. 583-585.

. Hong, J.-S., M.J.J.I.T.o.M.t. Lancaster, and Techniques, Couplings of microstrip square open-loop resonators for cross-coupled planar microwave filters. 1996. 44(11): p. 2099-2109.

. Konpang, J. A compact diplexer using square open loop with stepped impedance resonators. in 2009 IEEE Radio and Wireless Symposium. 2009. IEEE.

. Ammar, A.E., et al., Efficient Diplexer with High Selectivity and Low Insertion Loss Based on SOLR and DGS for WIMAX. 2021. 116: p. 171-180.

. Guan, X., et al., Compact and high-isolation diplexer using dual-mode stub-loaded resonators. 2014. 24(6): p. 385-387.

. Da Xu, K., et al., Design of triplexer using E-stub-loaded composite right-/left-handed resonators and quasi-lumped impedance matching network. 2018. 6: p. 18814-18821.

. Jenq, F.L., K.K. Chong, and L.Q.J.J.o.A.S. Zeng, Overcoupled response improvement with miniaturizing of rectangular dual-mode filter by slow-wave modified resonator. 2009. 9(15): p. 2841-2846.

. Li, M., et al., Compact diplexer using short stub‐loaded composite right/left‐handed resonators. 2017. 59(6): p. 1470-1474.

. Yao, H.-W., et al., Wide-band waveguide and ridge waveguide T-junctions for diplexer applications. 1993. 41(12): p. 2166-2173.

. Li, Q., et al., Compact and high‐isolation microstrip diplexer using distributed coupling feeding line. 2018. 60(1): p. 192-196.

. Zhang, P., M.-H. Weng, and R.-Y.J.E. Yang, A compact wideband diplexer using stub-loaded square ring resonators. 2021. 41(3): p. 167-184.

. Xiao, J.-K., et al., High selective microstrip bandpass filter and diplexer with mixed electromagnetic coupling. 2015. 25(12): p. 781-783.

. Cheng, F., et al., High isolation substrate integrated waveguide diplexer with flexible transmission zeros. 2020. 30(11): p. 1029-1032.

. Hassan, A.Y., et al., A compact diplexer using coupled π-CRLH zeroth resonators. 2021: p. 1-8.

Downloads

Published

2022-05-22

Issue

Section

Articles