Optimized dimensions of ultra wideband quasi-complementary antenna with switching capability

This paper presents a study and comparison of complementary antenna structures to find an optimized case for the UWB frequency range. An auto-complementary antenna and quasi-complementary antennas are used as a reference to find an optimized quasi-complementary structure. With the optimized structure, the achieved frequency range is up from 2.22 GHz with impedance matching less than -10 dB. After finding the optimized case, the antennas are split to half as a monopole, and the monopole is added to the end of the ground plane of a portable device. With the optimized antenna structure, the -10 dB impedance bandwidth starts from 3.2 GHz without exceeding the -10 dB limit compared to reference. As a final step, a switching capability is studied to achieve frequency response around 1 GHz.