Two-and four-way Wilkinson power divider design with slow-wave microstrip structures

In this study, conventional Wilkinson power dividers have been modified with meandered transmission line structures, resulting in two-port power dividers with either two or three serial connections and four-port power dividers with two serial connections. A substrate with a relative permittivity of 10.2 and a height of 1.27 mm, RT/Duroid, was used for the designs, and frequency responses were optimized using an electromagnetic simulation program. To enhance isolation and bandwidth, 100-ohm resistors were placed at each connection point in the power dividers. In the two-port configuration with two serial connections, the average return loss was-14.45 dB, insertion loss was-3.40 dB, and isolation was-13.25 dB over the 0.17-1.36 GHz band. Additionally, in the 2.24-2.97 GHz frequency band, the return loss was-15.45 dB, insertion loss was-3.50 dB, and isolation was-15.93 dB. In the three-port configuration with three serial connections, the average return loss was-14.73 dB, insertion loss was-3.38 dB, and isolation was-12.20 dB over the 0.11-1.05 GHz range;-15.21 dB return loss,-3.54 dB insertion loss, and-15.34 dB isolation over the 1.36-2.10 GHz range; and-17.52 dB return loss,-3.65 dB insertion loss, and-14.03 dB isolation over the 2.59-3.14 GHz range. In the four-port configuration with two serial connections, the average return loss was-20.65 dB, insertion loss was-6.17 dB, and isolation was-16.74 dB in the 0.47-1.17 GHz range. The designed circuits were fabricated, and it was observed that the simulation results were consistent with the measurement results.