Miniaturized Ultra-Wideband Self-Complementary Antennas Using High Permittivity Thick Resin Material

A miniaturized self-complementary antenna for Japanese UWB higher band (7.25 GHz-10.25 GHz) is demonstrated. Input impedances of four antennas in the size of 30 mm, 20 mm, 15 mm, 10 mm each on 1 mm and 2 mm thick high permittivity (epsiv_r = 10.2 ) resin substrates were measured and extracted. With the extracted input impedance, 50 Omega-matched self-complementary antennas in the size of 10 mm were designed and fabricated. The measured return loss was less than -10 dB between 5.9 GHz and 13.8 GHz and the fractional bandwidth was 80%. The fabricated antenna size is almost equivalent with the broadband antenna´s minimum size Chu showed ^[1]. Measured radiation patterns were almost omni-directional between 6 GHz and 12 GHz.