A Method for Reducing the Influence of the Limited Ground and Coaxial Feeder on Monopole Radiation

To eliminate the influence of the limited ground and coaxial line on the radiation pattern of the monopole and increase the gain of monopole along the ground direction, a printed circular monopole antenna with a printed choke which is fed by Coplanar Waveguide (CPW)is proposed and analyzed. The antenna is fed by coaxial line and a finite large circular ground is also loaded on the antenna. It is simulated in CST Microwave Studio software®. Simulation results show that the operating frequency band of the antenna is 3.83 GHz-4.06 GHz with its reflection coefficient less than −10 dB. By comparing the simulation results of antenna with and without the choke, it can be concluded that antenna with the choke improved the gain along the direction of the ground at about 13 dB compared with the antenna without choke. This method can be used to decrease the influence of the ground and ceiling on the direction pattern of monopole antenna.