Spoof Surface Plasmon Polaritons Based Antenna and Array by Exciting both Even and Odd Mode Resonances

Spoof surface plasmon polaritons (SSPPs) based antenna and array by exciting both even and odd mode resonances are developed and investigated in this paper. Different from others' work and for the first time, we use the separated corrugated grooves to achieve the consistent fundamental even and odd mode resonances on the same SSPPs aperture. In this way, the even and odd mode resonances can be operated in the same frequency band. Also for the first time, we introduce the SSPPs into an orthogonal-mode resonated antenna pursuing high isolated radiation. New challenges including the feed methods and impedance matching of two different resonant modes are overcome by introducing the capacitive patch and triangular cuts on the SSPPs. Finally, the SSPPs antenna and array were tested for performance investigation. It is found that in addition to the obtained wide overlapped impedance bandwidth of 14.8%, a very high isolation of 29 dB is achieved in the developed compact antenna element. The couplings between other antenna elements, radiation patterns, gains, and efficiencies of the array are also investigated. Both the measured and simulated results show that SSPPs and the developed antenna can be very appealing in MIMO applications owing to their orthogonal even-odd modes and compact structures.