Design of Dual-Frequency Wilkinson Divider Using Periodically Loaded Slow Wave Structure

Aiming at the drawback that a conventional Wilkinson power divider occupies more space and operates only at one design frequency and at all of its odd harmonics，a Wilkinson power divider operating at two arbitrary different frequencies is presented by combining a parallel RLC resonant network and a quarter wavelength impedance transformer which is consist of two different charac? teristic impedance transmission-lines. The miniaturization is achieved by realizing the power divider’s impedance transformers using slow wave structures which are designed by periodically loading transmission lines with capacitances. For dual-band application，we se? lected two bands at 900 and 1800 MHz. The substrate used was FR4 with a dielectric constant of 4.6. According to the simulated and measured results，three ports of the divider meet a good matching with the S11 -25 dB，S22 -26 dB，S21 -3.23 dB at 900 MHz and S11 -23 dB，S22 -17.5 dB and S21 -3.39 dB at 1800 MHz，which verifies the usability of the method.