Self-decoupled tapered slot antenna using defected radiator structure

A self-decoupled tapered slot antenna (TSA) by rejecting the coupling wave is proposed in this paper. Such TSA arrays have high isolation without introducing additional decoupling structures. And compared with the reference TSA, the self-decoupled TSA is obtained by the defected radiator structure, which is etched with multiple continuous cross grooves on the two fins of TSA. The reason why the defected radiator structure can be decoupled is that it has a band-stop characteristic within the operating frequency band of the TSA. The TSA with and without the defected radiator structure is studied that the TSA with defected radiator structure achieves ultra-wideband decoupling from 3 to 11 GHz. Moreover, the gain of the self-decoupled TSA is improved at most frequencies. A prototype of the self-decoupled TSA and the reference TSA are fabricated and measured. An excellent agreement between simulated and measured results is obtained. The isolation level of the self-decoupled TSA improves by a maximum of 12 dB at 6 GHz. The mutual coupling is reduced by 1 to 12 dB over the entire operating frequency band. In addition, the peak gain of the self-decoupled TSA is improved by up to 1.5 dBi.