A Broadband Monopole Antenna of Trapezoid Patch by Coplanar Waveguide

The design of a broadband trapezoid patch antenna is presented. The antenna is based on FR4 as the substrate. And the U-shaped slot is embedded in the trapezoidal patch. Then the bottom of trapezoid patch is connected with a rectangular microstrip feeder line. Two ground planes are attached beside the microstrip feeder line. Meanwhile, a coaxial probe made of copper is placed on the microstrip feeder line as the excitation, to expand the operation of broadband. The antenna is a monopole antenna fed by coplanar waveguide. And the development trend and choice of the antenna is analyzed and described in this paper. Then the structure of antenna is designed and analyzed. Finally, it is simulated by ANSYS HFSS and several key parameters are studied, the optimal impedance bandwidth is obtained. The measured result shows that the impedance bandwidth (S11 ≤-10 dB) is about 27%.