Practical realization of self-complementary broadband antenna on low-loss resin substrate for UWB applications

Practical realizations of self-complementary ultra-wideband antennas on low-loss resin materials are demonstrated. Dependences of broadband characteristics on sizes and shapes are clarified by simulations and experiments. The self-complementary antennas impedance-matched to a 50-ohm system, utilizing a 3-stage Chebyshev transformer over the UWB band, were designed and fabricated on a resin material (the relative permittivity; /spl epsiv//sub r/=3.6). A measured return loss of less than -9.8 dB and a measured absolute gain of 0-3 dBi over a frequency range from 3.1 to 10.6 GHz (the UWB band) were obtained with a 30 mm/spl times/60 mm sized antenna. A reduced sized antenna (20 mm/spl times/40 mm), designed and fabricated on a resin material of /spl epsiv//sub r/=10.2, delivered a return loss of less than -7.8 dB with an isotropic radiation pattern.