A novel 180˚ out-of-phase power divider with complex-source to complex-load impedance transformation and high power-handling capability is proposed in this paper. It is composed of three double-sided parallel-strip lines (DSPSLs), a conduct plane in the middle as common ground, and two resistors for heat sinking and high isolation. Based on the rigorous odd- and even-mode analytical methods, closed-form design equations about electrical parameters are obtained. To demonstrate our design theory, a practical three-layer out-of-phase power divider is designed, simulated and measured. The measured results show that the return losses |Sii| (i=1, 2, and 3) are all larger than 17 dB. The insertion loss |S21| (|S31|) is 3.6 dB (3.7 dB). The isolation |S23| is -24 dB, and the output phase difference is -177˚ at the operating frequency. Good agreements between the simulated and measured results verify our design theory.
2. Lin, W. and Q. X. Chu, "A novel RFID tag antenna for matching complex impedances on 915 MHz and 2.45GHz bands," 2010 Asia-Pacific Microwave Conference, APMC, 2248-2251, Yokohama, Japan, Dec. 2010.
3. Liu, Y., Y. J. Zhao, S. B. Liu, Y. G. Zhou, and Y. Chen, "Multi-frequency impedance transformers for frequency-dependent complex loads," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 9, 3225-3235, 2013.
4. Ahn, H. R. and S. Nam, "3-dB power dividers with equal complex termination impedances and design methods for controlling isolation circuits," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 11, 3872-3883, 2013.
5. Zhang, W. W., Y. A. Liu, Y. L. Wu, W. M. Wang, M. Su, and J. C. Gao, "A complex impedance-transforming coupled-line Balun," Progress In Electromagnetics Research Letters, Vol. 48, 123-128, 2014.
6. Michaelsen, R. S., T. K. Johansen, and K. M. Tamborg, "Analysis and design of complex impedance transformingMarchand baluns," 20th International Conference on Microwaves, Radar and Wireless Communications, MIKON 2014, Gdansk, Poland, Jun. 2014.
7. Chen, J.-X., C. H. K. Chin, K. W. Lau, and Q. Xue, "180? out-of-phase power divider based on double-sided parallel striplines," Electron. Lett., Vol. 42, No. 21, 1229-1230, Oct. 2006.
8. Lu, Y. L., G. L. Dai, X. C. Wei, and E. P. Li, "A broadband out-of-phase power divider for high power applications using through ground via (TGV)," Progress In Electromagnetics Research, Vol. 137, 653-667, 2013.
9. Milligan, T. A., "Transmission-line transformation between arbitrary impedances," IEEE Trans. Microw. Theory Tech. (Letters), Vol. 24, No. 3, 159, Mar. 1976.
10. Potok, M. H. N., "Comments on ‘Transmission-line transformation between arbitrary impedances’," IEEE Trans. Microw. Theory Tech., Vol. 25, No. 1, 77, Jan. 1977.