This paper presents a miniaturized Wilkinson power divider (WPD) with higher order harmonics suppression. The proposed power divider is designed for global system for mobile communication (GSM) application. The quarter wavelength lines of the conventional WPD are replaced by stub loaded transmission line in order to miniaturize the circuit size. A solution, operating at 1.8 GHz center frequency, has shown that the 2nd and 3rd order harmonics are well suppressed by a level < -15 dB. Further, two differently shaped defected ground structures (DGS) are embedded with the design to suppress the higher order harmonics. Therefore, overall 31% size reduction is achieved, and higher order harmonics are suppressed up to the 9th order (16 GHz) by a level < -15 dB compared to reference WPD. The return loss and isolation performance of the proposed WPD are < -15 dB and < -20 dB, respectively.
2. Wilkinson, E. J., "An n-way hybrid power divider," IRE Transactions on Microwave Theory and Techniques, Vol. 8, 116-118, 1960.
3. Yi, K. H. and B. Kang, "Modified Wilkinson power divider for nth harmonic suppression," IEEE Microwave and Wireless Components Letters, Vol. 13, No. 5, 178-180, 2003.
4. Yang, J., C. F. Gu, and W. Wu, "Design of novel compact coupled microstrip power divider with harmonic suppression," IEEE Microwave and Wireless Components Letters, Vol. 18, No. 9, 572-574, 2008.
5. Hayati, M., S. Roshani, and S. Roshani, "Miniaturized Wilkinson power divider with nth harmonic suppression using front coupled tapered CMRC," ACES J, Vol. 28, No. 3, 221-227, 2013.
6. Zhang, Z., Y.-C. Jiao, and Z.-B. Weng, "Design of 2.4 GHz power divider with harmonic suppression," Electronics Letters, Vol. 48, No. 12, 705-707, 2012.
7. Hayati, M. and S. Roshani, "A novel Wilkinson power divider using open stubs for the suppression of harmonics," ACES J, Vol. 28, No. 6, 501-505, 2013.
8. Xu, X. and X. Tang, "Design of a compact Wilkinson power divider with high order harmonics suppression," Progress In Electromagnetic Research Letters, Vol. 50, 111-116, 2014.
9. Tseng, C. H., et al., "Compact planar Wilkinson power divider using pi-equivalent shunt-stub-based artificial transmission lines," Electronics Letters, Vol. 46, No. 19, 1327-1328, 2010.
10. Karimi, G. and S. Menbari, "A novel Wilkinson power divider using lowpass filter with harmonics suppression and high fractional bandwidth," Microelectronics Journal, Vol. 71, 61-69, 2018.
11. Shao, J.-Y., S.-C. Huang, and Y.-H. Pang, "Wilkinson power divider incorporating quasielliptic filters for improved out-of-band rejection," Electronics Letters, Vol. 47, No. 23, 1288-1289, 2011.
12. Eom, D. J., et al., "Fully printed dual-band power divider miniaturized by CRLH phase shift lines," ETRI J, Vol. 35, 150-153, 2013.
13. Lin, C.-M., et al., "Wilkinson power divider using microstrip EBG cells for the suppression of harmonics," IEEE Microwave and Wireless Components Letters, Vol. 17, No. 10, 2007.
14. Zhang, F. and C. F. Li, "Power divider with microstrip electromagnetic band gap element for miniaturization and harmonic rejection," Electronics Letters, Vol. 44, No. 6, 422-423, 2008.
15. Ooi, B.-L., "Compact EBG in-phase hybrid-ring equal power divider," IEEE Transactions on Microwave Theory and Techniques, Vol. 53, 2329-2324, 2005.
16. Ahn, D., et al., "A design of the low-pass filter using the novel microstrip defected ground structure," IEEE Transactions on Microwave Theory and Techniques, Vol. 49, No. 1, 86-93, 2001.
17. Lim, J. S., et al., "A 4 : 1 unequal Wilkinson power divider," IEEE Microwave and Wireless Components Letters, Vol. 11, 124-126, 2001.
18. Park, J. S., et al., "A design of the novel coupled line bandpass filter using defected ground structure with wide stopband performance," IEEE Transactions on Microwave Theory and Techniques, Vol. 50, No. 9, 2037-2043, 2002.
19. Kim, J. S., et al., "A 10 dB branch line coupler using defected ground structure," 30th Eur: Microwave Conferance Dig., Vol. 3, 68-71, 2001.
20. Woo, D.-J., et al., "Suppression of harmonics in Wilkinson power divider using dual-band rejection by asymmetric DGS," IEEE Transactions on Microwave Theory and Techniques, Vol. 53, No. 6, 2139-2144, 2005.
21. Ning, J., Z. Luo, and S. Bu, "A simple design of planar harmonic-suppressed filters using shunt open stubs," IEEE Circuits and Systems International Conference on Testing and Diagnosis, 1-3, Chengdu, 2009.