A miniaturized Wilkinson power divider for MMIC applications

The miniaturization of the conventional Wilkinson power divider using stepped impedance lines and series delta /rectangular stubs is presented. A new technique to improve the output port isolation using a capacitive network is introduced in the proposed circuit. The measured insertion loss is less than 0.6 dB and the measured input referred return loss is better than -10 dB across the frequency range 5 GHz-43 GHz. The port isolation is measured to be better than -10 dB from 20.3 GHz to 43 GHz with a maximum of -26.5 dB at 36.5 GHz. High fractional bandwidth of 80% and an overall size reduction of 57% were achieved using the proposed techniques at the center frequency of 33 GHz.