Modified Wilkinson power divider with harmonics suppression and compact size for GSM applications

In this article, a modified microstrip Wilkinson power divider with harmonics suppression for GSM communications applications is presented. For low-pass filter designing, one open stub, one radial resonator, and two rectangular resonators are used. According to results related to insertion losses (|S₂₁| and |S₃₁|), stopband is wide and equal to 7.5 GHz (3.4-10.9 GHz), under the condition of 20 dB harmonic suppression level. The results show that at the designed frequency of 1.8 GHz, the input return loss (|S₁₁|) and output return losses (|S₂₂| and |S₃₃|) are better than 22 dB, and the isolation between of output ports (|S₃₂|) is better than 30 dB. The size of the proposed power divider is compact and equal to 10.6 × 14.6 mm². Finally, the proposed power divider was fabricated and the measurement results illustrate a good agreement with simulation results.