A novel miniaturized wideband plane omnidirectional antenna with 3.4-7.4 GHz band is designed in this paper.Based on traditional circular monopole planar antenna,the antenna introduces a Wilkinson power divider,a tapered microstrip feeder,and a bottled floor structure.A Wilkinson power divider is introduced at the microstrip feeder to improve the unroundness of pattern,which achieves better omnidirectional radiation;and a metal ground floor of bottle shaped structure is printed on the back of this antenna to achieve good impedance matching effect.The results show that the planar omnidirectional antenna has impedance bandwidth of 4 GHz,the gain at the center frequency of 5.4 GHz is 3.35 dB,the unroundness of radiation pattern at the center frequency of 5.4 GHz is less than 3.50 dB,and the gain at the whole impedance bandwidth is 2.3-3.35 dB.The simulation results are basically consistent with the measured results.