An unequal wilkinson power divider with a high dividing ratio

We present the design and performance of an unequal Wilkinson power divider with a high dividing ratio. To obtain the unequal high-ratio feature, we propose a microstrip line with a periodic shunt open stub to achieve low-impedance lines. The periodic shunt capacitive loading of microstrip lines can be converted a low-impedance line to a high-impedance line because of low effective characteristic impedance and phase velocity. This enables the microstrip line fabrication to be achieved with a low characteristic impedance line of below 10 Ω. As a design example, a 10:1 divider was designed and measured at 1 GHz to show the validity of the unequal divider using periodic open stub. Its performance is in good agreements with the simulated results.