Integration of multiple functions is for the first time achieved within a single patch element. Firstly, out of phase equal power division and bandpass filter characteristics are combined within a patch element. The novelty of the proposed structure is to use simple asymmetric cross slots in the patch element to achieve this integration. A simplified equivalent circuit model to describe operation of this patch element is proposed. Coplanar waveguide/microstrip broadside coupling is then investigated to enhance the performance of the patch balanced filter and eliminate narrow coupling gaps and microstrip lines. Subsequently, transition between microstrip and coplanar waveguide is then added to the patch element by using certain electromagnetic coupling methods for higher level integration without introducing additional loss. Different patch elements operating at 2.4 GHz are developed to validate the feasibility of the proposed structures. The circuits were designed, fabricated and measured. The measured results agree quite well with the simulation, exhibiting small amplitude and phase imbalance at the output ports throughout the desired passband, and good rejection levels elsewhere.
Shao Yong Zheng,
Wing Shing Chan,
Kim Fung Man,
"Multi-Function Patch Element," Progress In Electromagnetics Research,
Vol. 109, 159-174, 2010. doi:10.2528/PIER10081801
1. Yang, Z. Q., T. Yang, and Y. Liu, "Aanalysis and design of a reduced-size marchand balun," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 9, 1169-1175, 2007.
2. Rogers, J. and R. Bhatia, "A 6 to 20 GHz planar balun using a Wilkinson divider and Lange coupler," IEEE MTT-S Int. Symp. Dig., Vol. 2, 865-868, Jul. 1991.
3. Park, M.-J. and B. Lee, "Stubbed branch line balun," IEEE Microw. Wirel. Compon. Lett., Vol. 17, No. 3, 169-171, Mar. 2007. doi:10.1109/LMWC.2006.890445
4. Guglielmi, M. and G. Gatti, "Experimental investigation of dual-mode microstrip ring resonators," Proc. 20th Eur. Microwave Conf., 901-906, Sep. 1990.
5. Zhu, L., B. C. Tan, and S. J. Quek, "Miniaturized dual-mode bandpass filter using inductively loaded cross-slotted patch resonator," IEEE Microw. Wirel. Compon. Lett., Vol. 15, No. 1, Jan. 2005. doi:10.1109/LMWC.2005.859967
6. Alhawari, A. R. H. and A. Ismail, "Compact wideband bandpass filter using single corners-cut isosceles triangular patch resonator," Progress In Electromagnetics Research C, Vol. 14, 227-237, 2010. doi:10.2528/PIERC10060102
7. Le Nadan, T., J. P. Coupez, S. Toutain, and C. Person, "Optimization and miniaturization of a filter/antenna multi-function module using a composite ceramic-foam substrate," IEEE MTT-S Inti. Microw. Symp. Dig., 219-222, 1999.
8. Yeung, L. K. and K.-L. Wu, "An integrated RF balanced-filter with enhanced rejection characteristics," IEEE MTT-S Inti. Microw. Symp. Dig., Vol. 2, 713-716, 2005. doi:10.1109/MWSYM.2005.1516708
9. Jung, E. Y. and H. Y. Hwang, "A Balun-BPF using a dual mode ring resonator," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 9, 652-654, Sep. 2007. doi:10.1109/LMWC.2007.903442
10. Iwasaki, H., "A circularly polarized small-size microstrip antenna with a cross slot," IEEE Trans. Antennas Propagat., Vol. 44, No. 10, 1399-1401, Oct. 1996. doi:10.1109/8.537335
11. Khodaei, G. F., J. Nourinia, and C. Ghobadi, "A practical miniaturized U-slot patch antenna with enhanced bandwidth," Progress In Electromagnetics Research B, Vol. 3, 47-62, 2008. doi:10.2528/PIERB07112201
12. Singh, Y. K. and A. Chakrabarty, "Miniaturized dual-mode circular patch bandpass filters with wide harmonic separation," IEEE Microw. Wirel. Compon. Lett., Vol. 18, No. 9, 584-586, Sep. 2008. doi:10.1109/LMWC.2008.2002449
13. Weng, M. H., S. Wu, S. B. Jhong, Y. C. Chang, and M. S. Lee, "A novel compact dual-mode filter using cross-slotted patch resonator for dual-band applications," IEEE MTT-S Int. Microwave Symp. Dig., 921-924, 2007.
14. Weng, L. H., Y.-C. Guo, X.-W. Shi, and X.-Q. Chen, "An overview on defected ground structure," Progress In Electromagnetics Research B, Vol. 7, 173-189, 2008. doi:10.2528/PIERB08031401