Design of a multiband ground radiation antenna by utilizing balun excitation.

The design and performance of a triple‐band ground radiation antenna with a compact balun are shown in this paper. A microstrip balun is integrated with a modified rectangular ground plane has provided wideband frequency characteristics. With the help of the theory of the characteristic mode, the resonance phenomenon of the rectangular ground plane is analyzed. An eight‐like‐loop slit is embedded in the ground plane to excite multiple resonant modes. In, addition, by etching two rectangular slots at two terminals of the eight‐like‐loop slit, the capacitance of the ground‐plane resonator decreases such that the impedance‐matching condition in the upper‐frequency band can be improved. Finally, a triple‐band frequency performance is derived by embedding a simple matching circuit. The proposed antenna achieves the measured impedance bandwidths from 1.02 to 1.06, from 1.35 to 1.62, and from 1.96 to 2.55 GHz. The simulated current distributions of a ground‐plane prototype are also experimentally verified. [ABSTRACT FROM AUTHOR]