Wideband non-traveling-wave triple-mode slotline antenna

摘要

Design approach of a novel, triple-mode wideband slotline antenna is proposed and studied. The proposed antenna is realised and implemented by employing the multiple resonant modes within a narrow slotline radiator, rather than utilising the traveling-wave effect. At first, a triple-digit, fork-like microstrip tuning stub is used to excite the first and the second odd-order mode within a slim, 3/2-wavelength slotline radiator. Then, a pair of slotline stubs is introduced near the E-field nulls of the third odd-order mode. By finely tuning the parameters of the microstrip/slotline stubs, the three radiation modes are perturbed and merged to generate a wideband, radiation characteristic with three resonances. Prototype antennas are then fabricated and measured. Finally, the design approach is experimentally validated. It is shown that the proposed antenna's radiation bandwidth has been effectively increased to 33.2% while keeping a single, basic-form narrow slotline radiator with a simple, non-traveling-wave configuration.