This paper proposes an unequal power divider with different terminated impedances and different electrical lengths for four uniform transmission lines. The proposed power divider consists of four transmission lines with different electrical lengths and an isolation resistor. Under different port impedances, the splitting ratio of the proposed divider can be adjusted to desired values by varying the electrical lengths of the divider transmission lines with uniform impedances. To verify the feasibility of the proposed divider, two circuits were designed with dividing ratios of 2:1 and 4:1 at an operating frequency of 2 GHz. The circuits used a uniform impedance of 40 Ω at terminated impedances of 50, 70, and 60 Ω. The performance showed excellent agreement between the simulated and experimental results.
2. Jang, H., P. Roblin, C. Quindroit, Y. Lin, and R. D. Pond, "Asymmetric Doherty power amplifier designed using model-based nonlinear embedding," IEEE Trans. Microwave Theory & Tech., Vol. 62, No. 12, 3436-3451, Dec. 2014.
3. Li, B., X. Wu, and W. Wu, "A 10 : 1 unequal Wilkinson power divider using coupled lines with two shorts," IEEE Microwave Wireless Compon. Lett., Vol. 19, No. 12, 789-791, Dec. 2009.
4. Lim, J., S. Lee, C. Kim, J. Park, D. Ahn, and S. Nam, "A 4 : 1 unequal Wilkinson power divider," IEEE Microwave Wireless Compon. Lett., Vol. 11, No. 3, 124-126, Mar. 2001.
5. Cheng, K. K. M. and P.-W. Li, "A novel power-divider design with unequal power-dividing ratio and simple layout," IEEE Trans. Microwave Theory & Tech., Vol. 57, No. 6, 1589-1594, Jun. 2009.
6. Horst, S., R. Bairavasubramanian, M. M. Tentzeris, and J. Papapolymerou, "Modified Wilkinson power dividers for millimeter-wave integrated circuits," IEEE Trans. Microwave Theory & Tech., Vol. 55, No. 11, 2439-2446, Nov. 2007.
7. Qi, T., S. He, Z. Dai, and W. Shi, "Novel unequal dividing power divider with 50 Ω characteristic impedance lines," IEEE Microwave Wireless Compon. Lett., Vol. 26, No. 3, 180-182, Mar. 2016.
8. Chiu, L. and Q. Xue, "A parallel-strip ring power divider with high isolation and arbitrary power-dividing ratio," IEEE Trans. Microwave Theory & Tech., Vol. 55, No. 11, 2419-2426, Nov. 2007.
9. Lee, J.-G., J.-C. Lee, and M.-J. Park, "Branch-line couplers with arbitrary coupling value through the electrical length variation with fixed line impedances," IEEE Microwave Wireless Compon. Lett., Vol. 27, No. 11, 968-970, Nov. 2017.
10. Parad, L. I. and R. L. Moynihan, "Split-tee power divider," IRE Trans. Microwave Theory & Tech. MTT-8, Vol. 13, No. 1, 91-95, Jan. 1965.
11. Ahn, H.-R. and I. Wolff, "Three-port 3-dB power divider terminated by different impedances and its application to MMIC’s," IEEE Trans. Microwave Theory & Tech., Vol. 47, No. 6, 786-794, Jun. 1999.